diff --git a/KNOWLEDGE_BASE.md b/KNOWLEDGE_BASE.md
index 8f1d9baa9..a73b4cc22 100644
--- a/KNOWLEDGE_BASE.md
+++ b/KNOWLEDGE_BASE.md
@@ -113,9 +113,11 @@ GitHub organizations, like `@laravel`, have a page at `/@{handle}` too, with the
 
 The **Mentions** tab lists the commits and replies that mention the organization, newest first, a reply with the commit it answers. A commit stays listed after the organization is renamed, since it is linked to the organization rather than to the handle. It follows the usual visibility: guests see approved commits only, you also see your own pending ones, and commits across a block or by people you muted are left out.
 
+Members of an organization can **Claim** its page, which lists them as its admins. Claiming asks GitHub once for permission to read your organizations, then checks that you are an owner or a member there, not just invited. Organizations that restrict third-party apps only share their members once an owner approved /dev/null: the page then links to GitHub, where an owner grants access and a member requests it. GitHub is only the way in: leaving the organization on GitHub doesn't remove you as an admin on /dev/null. Claims are in your data export and go when you delete your account.
+
 Following organizations is planned, not shipped yet.
 
-Sources: [organization page](resources/js/pages/organization/show.tsx), [mentions](app/Queries/OrganizationMentionsQuery.php), [organization lookups](app/Actions/UpdateCommitTopics.php).
+Sources: [organization page](resources/js/pages/organization/show.tsx), [mentions](app/Queries/OrganizationMentionsQuery.php), [organization lookups](app/Actions/UpdateCommitTopics.php), [claims](app/Http/Controllers/OrganizationAdminController.php).
 
 ### Going live
 
diff --git a/app/Actions/CreateExport.php b/app/Actions/CreateExport.php
index c8c9e48c5..079d84250 100644
--- a/app/Actions/CreateExport.php
+++ b/app/Actions/CreateExport.php
@@ -44,6 +44,7 @@
  *     muting: Generator<int, ExportUser>,
  *     blocking: Generator<int, ExportUser>,
  *     dismissed_suggestions: Generator<int, ExportUser>,
+ *     claimed_organizations: array<int, array{handle: string, claimed_at: string}>,
  *     messages: Generator<int, ExportMessage>,
  *     remote_pins: array<int, array{to: string|null, pinned_at: string|null}>,
  *     remote_mutes: array<int, array{to: string|null, muted_until_at: string|null}>,
@@ -110,6 +111,7 @@ public function handle(User $user): array
             'muting' => $this->handles($user->muting()),
             'blocking' => $this->handles($user->blocking()),
             'dismissed_suggestions' => $this->handles($user->dismissedSuggestions()),
+            'claimed_organizations' => $this->claimedOrganizations($user),
             'messages' => $this->messages($user),
             'remote_mutes' => Conversation::query()
                 ->join('conversation_participants as mine', 'mine.conversation_id', '=', 'conversations.id')
@@ -290,6 +292,23 @@ private function handles(BelongsToMany $users): Generator
         }
     }
 
+    /**
+     * @return array<int, array{handle: string, claimed_at: string}>
+     */
+    private function claimedOrganizations(User $user): array
+    {
+        /** @var Collection<int, object{handle: string, created_at: string}> $claims */
+        $claims = $user->claimedOrganizations()->newPivotQuery()
+            ->join('profiles', 'profiles.id', '=', 'organization_admins.organization_id')
+            ->oldest('organization_admins.created_at')
+            ->get(['profiles.handle', 'organization_admins.created_at']);
+
+        return $claims->map(fn (object $claim): array => [
+            'handle' => $claim->handle,
+            'claimed_at' => CarbonImmutable::parse($claim->created_at)->toIso8601String(),
+        ])->all();
+    }
+
     /**
      * Moderators stay anonymous, as they are on the notifications page, and level-ups are the user's own doing.
      *
diff --git a/app/Actions/CreateOrganizationAdmin.php b/app/Actions/CreateOrganizationAdmin.php
new file mode 100644
index 000000000..96102f357
--- /dev/null
+++ b/app/Actions/CreateOrganizationAdmin.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Actions;
+
+use App\Models\Profile;
+use App\Models\User;
+
+final readonly class CreateOrganizationAdmin
+{
+    /**
+     * Makes the user an admin of the organization's page, once GitHub confirmed they belong to it. Claiming again
+     * changes nothing.
+     */
+    public function handle(Profile $organization, User $user): void
+    {
+        $organization->admins()->syncWithoutDetaching([$user->id]);
+    }
+}
diff --git a/app/Actions/DeleteOrganization.php b/app/Actions/DeleteOrganization.php
index dc315b770..6354b35eb 100644
--- a/app/Actions/DeleteOrganization.php
+++ b/app/Actions/DeleteOrganization.php
@@ -11,8 +11,8 @@
 final readonly class DeleteOrganization
 {
     /**
-     * Deletes an organization GitHub no longer has, and unlinks the commits that mention it, so none links to a page
-     * that is gone.
+     * Deletes an organization GitHub no longer has, with its admins, and unlinks the commits that mention it, so none
+     * links to a page that is gone.
      */
     public function handle(Profile $organization): void
     {
@@ -22,6 +22,7 @@ public function handle(Profile $organization): void
                 ->where('topic_id', $organization->id)
                 ->delete();
 
+            $organization->admins()->detach();
             $organization->delete();
         });
     }
diff --git a/app/Actions/DeleteUser.php b/app/Actions/DeleteUser.php
index 8226ad8b0..56513ed1f 100644
--- a/app/Actions/DeleteUser.php
+++ b/app/Actions/DeleteUser.php
@@ -67,6 +67,8 @@ public function handle(User $user): void
 
             $this->deleteOrgs->handle($this->emptyOrgs($user));
 
+            $user->claimedOrganizations()->detach();
+
             $user->delete();
             $user->profile->delete();
 
diff --git a/app/Enums/GitHubOrganizationMembership.php b/app/Enums/GitHubOrganizationMembership.php
new file mode 100644
index 000000000..8e1aabc2c
--- /dev/null
+++ b/app/Enums/GitHubOrganizationMembership.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Enums;
+
+/**
+ * What GitHub says about a user's place in an organization, when they ask with the read:org scope.
+ */
+enum GitHubOrganizationMembership
+{
+    /** An owner or a member, who accepted the invitation. */
+    case Member;
+
+    case NotMember;
+
+    /** The organization restricts OAuth apps, and its owners haven't approved /dev/null. */
+    case Restricted;
+
+    /** The organization signs its members in with SAML, and the user hasn't signed in that way. */
+    case SingleSignOn;
+}
diff --git a/app/Http/Controllers/OrganizationAdminController.php b/app/Http/Controllers/OrganizationAdminController.php
new file mode 100644
index 000000000..fc4f06193
--- /dev/null
+++ b/app/Http/Controllers/OrganizationAdminController.php
@@ -0,0 +1,126 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Controllers;
+
+use App\Actions\CreateOrganizationAdmin;
+use App\Enums\GitHubOrganizationMembership;
+use App\Enums\ProfileType;
+use App\Http\Requests\CreateOrganizationAdminRequest;
+use App\Models\Profile;
+use App\Models\User;
+use App\Services\GitHub;
+use Illuminate\Container\Attributes\CurrentUser;
+use Illuminate\Http\RedirectResponse;
+use Illuminate\Http\Request;
+use Inertia\Inertia;
+use Laravel\Socialite\Socialite;
+use Laravel\Socialite\Two\GithubProvider;
+use Laravel\Socialite\Two\InvalidStateException;
+use Laravel\Socialite\Two\User as GitHubUser;
+use Symfony\Component\HttpFoundation\Response as SymfonyResponse;
+
+/**
+ * Claiming an organization's page asks GitHub, with the read:org scope sign-in doesn't ask for, whether the user
+ * belongs to the organization. The token is only used for that, and isn't kept.
+ */
+final readonly class OrganizationAdminController
+{
+    private const string CLAIMING = 'claiming-organization';
+
+    /**
+     * Claiming starts from a form, so no other site can send a user who already granted the scope through it.
+     */
+    public function create(CreateOrganizationAdminRequest $request, Profile $organization): SymfonyResponse
+    {
+        $request->session()->put(self::CLAIMING, $organization->id);
+
+        return Inertia::location($this->github()->scopes(['read:org'])->redirect()->getTargetUrl());
+    }
+
+    /**
+     * GitHub only sends back to a path under the callback registered for sign-in, so this is where it lands.
+     */
+    public function store(Request $request, #[CurrentUser] User $user, GitHub $github, CreateOrganizationAdmin $action): RedirectResponse
+    {
+        $organization = Profile::query()
+            ->where('type', ProfileType::Organization)
+            ->find($request->session()->pull(self::CLAIMING));
+
+        if (! $organization instanceof Profile) {
+            Inertia::flash('toast', ['type' => 'error', 'message' => __('Unable to claim this organization. Please try again.')]);
+
+            return to_route('log.show', $user->log);
+        }
+
+        $page = to_route('user.show', $organization->handle);
+
+        if ($request->has('error')) {
+            return $this->failed(__('GitHub was not asked about your organizations, so the page was not claimed.'), $page);
+        }
+
+        try {
+            $githubUser = $this->github()->user();
+        } catch (InvalidStateException) {
+            return $this->failed(__('Unable to claim this organization. Please try again.'), $page);
+        }
+
+        assert($githubUser instanceof GitHubUser);
+
+        if ((string) $githubUser->getId() !== $user->github_id) {
+            return $this->failed(__('GitHub is signed in as @:login. Sign in there as @:handle to claim this page.', [
+                'login' => $githubUser->getNickname(),
+                'handle' => $user->profile->handle,
+            ]), $page);
+        }
+
+        $handle = $organization->handle;
+
+        // An organization restricting OAuth apps hides its members from those its owners haven't approved, which they
+        // do from the app's page in their settings, where members request it.
+        $failure = match ($github->organizationMembership($githubUser->token, $handle, $organization->github_id)) {
+            GitHubOrganizationMembership::Member => null,
+            GitHubOrganizationMembership::NotMember => [__('GitHub says you are not a member of @:handle.', ['handle' => $handle]), null],
+            GitHubOrganizationMembership::Restricted => [
+                __('@:handle only shares its members with apps its owners approved. On GitHub, grant /dev/null access if you are an owner, or request it from them, then try again.', ['handle' => $handle]),
+                'https://github.com/settings/connections/applications/'.config()->string('services.github.client_id'),
+            ],
+            GitHubOrganizationMembership::SingleSignOn => [
+                __('@:handle signs its members in with single sign-on. Sign in to @:handle on GitHub, then try again.', ['handle' => $handle]),
+                "https://github.com/orgs/{$handle}/sso",
+            ],
+        };
+
+        if ($failure !== null) {
+            return $this->failed($failure[0], $page, $failure[1]);
+        }
+
+        $action->handle($organization, $user);
+
+        Inertia::flash('toast', ['type' => 'success', 'message' => __('You are now an admin of @:handle.', ['handle' => $organization->handle])]);
+
+        return $page;
+    }
+
+    /**
+     * GitHub sends the user back here rather than to sign-in, and checks the token is redeemed for the same URL.
+     */
+    private function github(): GithubProvider
+    {
+        $provider = Socialite::driver('github');
+        assert($provider instanceof GithubProvider);
+
+        return $provider->redirectUrl(route('organization-admin.store'));
+    }
+
+    /**
+     * The page says why the claim failed until the user leaves it, with where to approve /dev/null when that's why.
+     */
+    private function failed(string $message, RedirectResponse $redirect, ?string $approvalUrl = null): RedirectResponse
+    {
+        Inertia::flash('claimFailed', ['message' => $message, 'approvalUrl' => $approvalUrl]);
+
+        return $redirect;
+    }
+}
diff --git a/app/Http/Controllers/OrganizationController.php b/app/Http/Controllers/OrganizationController.php
index 2bfdbf0f1..b31aff726 100644
--- a/app/Http/Controllers/OrganizationController.php
+++ b/app/Http/Controllers/OrganizationController.php
@@ -10,6 +10,7 @@
 use App\Queries\OrganizationMentionsQuery;
 use App\Services\PageMetadata;
 use Illuminate\Container\Attributes\CurrentUser;
+use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Http\RedirectResponse;
 use Inertia\Inertia;
 use Inertia\Response;
@@ -18,8 +19,8 @@
 {
     /**
      * Organization pages are public, at the "@handle" of users, and show the organization's GitHub profile and the
-     * commits that mention it, with the organization's link preview. Like users' pages, they move for good to the
-     * handle's own case.
+     * commits that mention it, with the users who claimed it, first claim first, and the organization's link preview.
+     * Like users' pages, they move for good to the handle's own case.
      */
     public function show(ShowOrganizationRequest $request, #[CurrentUser] ?User $currentUser, OrganizationMentionsQuery $mentions, PageMetadata $metadata): RedirectResponse|Response
     {
@@ -40,6 +41,8 @@ public function show(ShowOrganizationRequest $request, #[CurrentUser] ?User $cur
             'commits' => Inertia::scroll(fn () => $mentions->builder($organization, $currentUser)
                 ->cursorPaginate(20)
                 ->appends(['tab' => $request->tab()])),
+            'claimUrl' => route('organization-admin.create', $organization),
+            'admins' => fn (): Collection => $organization->admins()->oldest('organization_admins.created_at')->get()->makeHidden('pivot'),
         ])->withViewData(['preview' => $currentUser instanceof User || $request->inertia() ? null : $metadata->organization($organization)]);
     }
 }
diff --git a/app/Http/Requests/CreateOrganizationAdminRequest.php b/app/Http/Requests/CreateOrganizationAdminRequest.php
new file mode 100644
index 000000000..5c5972c8d
--- /dev/null
+++ b/app/Http/Requests/CreateOrganizationAdminRequest.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Requests;
+
+use App\Enums\ProfileType;
+use App\Models\Profile;
+use Illuminate\Auth\Access\Response;
+use Illuminate\Foundation\Http\FormRequest;
+
+final class CreateOrganizationAdminRequest extends FormRequest
+{
+    /**
+     * Only organizations' pages can be claimed. A user's profile looks like it does not exist.
+     */
+    public function authorize(): Response
+    {
+        $organization = $this->route('organization');
+        assert($organization instanceof Profile);
+
+        return $organization->type === ProfileType::Organization ? Response::allow() : Response::denyAsNotFound();
+    }
+
+    /**
+     * @return array{}
+     */
+    public function rules(): array
+    {
+        return [];
+    }
+}
diff --git a/app/Models/Profile.php b/app/Models/Profile.php
index 2a17f4528..2dcac92e9 100644
--- a/app/Models/Profile.php
+++ b/app/Models/Profile.php
@@ -13,6 +13,7 @@
 use Illuminate\Database\Eloquent\Concerns\HasUuids;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasOne;
 use Illuminate\Database\Eloquent\Relations\Relation;
 
@@ -111,4 +112,15 @@ public function user(): HasOne
     {
         return $this->hasOne(User::class, 'github_id', 'github_id');
     }
+
+    /**
+     * The users who claimed the organization's page. GitHub only lets them in: leaving the organization there doesn't
+     * remove them here.
+     *
+     * @return BelongsToMany<User, $this>
+     */
+    public function admins(): BelongsToMany
+    {
+        return $this->belongsToMany(User::class, 'organization_admins', 'organization_id')->withTimestamps(updatedAt: false);
+    }
 }
diff --git a/app/Models/User.php b/app/Models/User.php
index 6a5f81113..44679049b 100644
--- a/app/Models/User.php
+++ b/app/Models/User.php
@@ -333,6 +333,16 @@ public function isBanned(): bool
         return $this->banned_at !== null;
     }
 
+    /**
+     * The organizations whose page the user claimed, see `Profile::admins()`.
+     *
+     * @return BelongsToMany<Profile, $this>
+     */
+    public function claimedOrganizations(): BelongsToMany
+    {
+        return $this->belongsToMany(Profile::class, 'organization_admins', 'user_id', 'organization_id')->withTimestamps(updatedAt: false);
+    }
+
     /**
      * @return BelongsToMany<Commit, $this>
      */
diff --git a/app/Services/GitHub.php b/app/Services/GitHub.php
index de5335e30..d6870134e 100644
--- a/app/Services/GitHub.php
+++ b/app/Services/GitHub.php
@@ -4,6 +4,7 @@
 
 namespace App\Services;
 
+use App\Enums\GitHubOrganizationMembership;
 use Illuminate\Http\Client\PendingRequest;
 use Illuminate\Support\Facades\Http;
 
@@ -52,6 +53,35 @@ public function login(string $githubId): ?string
         return $login;
     }
 
+    /**
+     * Where the user the token is for stands in the organization. The token needs the read:org scope. Matched by the
+     * organization's ID, so a renamed handle that someone else took since doesn't count.
+     */
+    public function organizationMembership(string $token, string $handle, string $githubId): GitHubOrganizationMembership
+    {
+        $response = $this->request($token)->get("user/memberships/orgs/{$handle}");
+
+        if ($response->notFound()) {
+            return GitHubOrganizationMembership::NotMember;
+        }
+
+        if ($response->forbidden() && $response->hasHeader('X-GitHub-SSO')) {
+            return GitHubOrganizationMembership::SingleSignOn;
+        }
+
+        if ($response->forbidden() && str_contains($response->fluent()->string('message')->value(), 'OAuth App access restrictions')) {
+            return GitHubOrganizationMembership::Restricted;
+        }
+
+        $membership = $response->throw()->fluent();
+
+        return $membership->string('state')->value() === 'active'
+            && in_array($membership->string('role')->value(), ['admin', 'member'], true)
+            && (string) $membership->integer('organization.id') === $githubId
+            ? GitHubOrganizationMembership::Member
+            : GitHubOrganizationMembership::NotMember;
+    }
+
     /**
      * The IDs of the accounts in a paginated list, such as the followers of a user, up to the given number of pages.
      *
diff --git a/database/migrations/2026_10_28_120000_create_organization_admins_table.php b/database/migrations/2026_10_28_120000_create_organization_admins_table.php
new file mode 100644
index 000000000..e9e44c6ad
--- /dev/null
+++ b/database/migrations/2026_10_28_120000_create_organization_admins_table.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * The users who claimed an organization's page, which GitHub confirmed they belong to. Everyone sees them on the
+     * page. A user's rows go when they erase their account, and an organization's when GitHub no longer has it.
+     */
+    public function up(): void
+    {
+        Schema::create('organization_admins', function (Blueprint $table): void {
+            $table->foreignUuid('organization_id')->constrained('profiles');
+            $table->foreignUuid('user_id')->constrained();
+            $table->timestamp('created_at');
+
+            $table->primary(['organization_id', 'user_id']);
+            $table->index('user_id');
+        });
+    }
+};
diff --git a/resources/js/lib/legal.ts b/resources/js/lib/legal.ts
index 5579bbbdc..63e0484c4 100644
--- a/resources/js/lib/legal.ts
+++ b/resources/js/lib/legal.ts
@@ -1,4 +1,4 @@
-export const PRIVACY_EFFECTIVE_DATE = '28 October 2026';
+export const PRIVACY_EFFECTIVE_DATE = '29 October 2026';
 
 export const TERMS_EFFECTIVE_DATE = '25 October 2026';
 
diff --git a/resources/js/pages/organization/show.tsx b/resources/js/pages/organization/show.tsx
index d2f508e6a..03f756a1b 100644
--- a/resources/js/pages/organization/show.tsx
+++ b/resources/js/pages/organization/show.tsx
@@ -1,5 +1,6 @@
-import { Head } from '@inertiajs/react';
-import { Link2, MapPin } from 'lucide-react';
+import { Head, Link, usePage } from '@inertiajs/react';
+import { AlertCircleIcon, Link2, MapPin } from 'lucide-react';
+import { useState } from 'react';
 import { show } from '@/actions/App/Http/Controllers/UserController';
 import { BioText } from '@/components/bio-text';
 import { CommitFeed, EmptyFeed } from '@/components/commit-feed';
@@ -7,18 +8,35 @@ import { GitHubIcon } from '@/components/github-icon';
 import { OrganizationAvatar } from '@/components/organization-avatar';
 import { PageTabs } from '@/components/page-tabs';
 import { ProfileShareButton } from '@/components/profile-share-button';
+import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
+import { Button } from '@/components/ui/button';
+import { UserAvatar } from '@/components/user-avatar';
 import AppLayout from '@/layouts/app-layout';
-import type { Commit, CursorPaginated, Organization } from '@/types';
+import type { Commit, CursorPaginated, Organization, User } from '@/types';
 
 export default function Show({
     organization,
     tab,
     commits,
+    claimUrl,
+    admins,
 }: {
     organization: Organization & { id: string };
     tab: 'mentions';
     commits: CursorPaginated<Commit>;
+    claimUrl: string;
+    admins: User[];
 }) {
+    const { props, flash } = usePage();
+    const { auth } = props;
+    // Kept until the user leaves the page, as the background reloads bring no flash and would hide it.
+    const [claimFailed] = useState(flash.claimFailed);
+    // While a claim failed, its alert offers to try again instead.
+    const canClaim =
+        auth.user !== null &&
+        claimFailed === undefined &&
+        !admins.some((admin) => admin.id === auth.user?.id);
+
     return (
         <>
             <Head title={`${organization.name} (@${organization.handle})`} />
@@ -41,6 +59,14 @@ export default function Show({
                     />
 
                     <div className="flex shrink-0 gap-1.5 sm:gap-2">
+                        {canClaim && (
+                            <Button variant="outline" asChild>
+                                {/* A form, so no other site can claim for the user. The server sends them on to GitHub. */}
+                                <Link href={claimUrl} method="post" as="button">
+                                    Claim
+                                </Link>
+                            </Button>
+                        )}
                         <ProfileShareButton
                             handle={organization.handle}
                             href={show(organization).url}
@@ -99,6 +125,62 @@ export default function Show({
                         </a>
                     </li>
                 </ul>
+
+                {admins.length > 0 && (
+                    <div className="mt-4 flex flex-wrap items-center gap-2 text-sm text-muted-foreground">
+                        <span>Admins</span>
+                        {admins.map((admin) => (
+                            <Link
+                                key={admin.id}
+                                href={show(admin.handle)}
+                                className="flex items-center gap-1.5 text-foreground hover:underline"
+                            >
+                                <UserAvatar
+                                    user={admin}
+                                    className="size-5"
+                                    pixels={40}
+                                />
+                                @{admin.handle}
+                            </Link>
+                        ))}
+                    </div>
+                )}
+
+                {claimFailed && (
+                    <Alert className="mt-4 border-destructive-foreground/40 [&>svg]:text-destructive-foreground">
+                        <AlertCircleIcon />
+                        <AlertTitle className="text-destructive-foreground">
+                            Couldn't claim @{organization.handle}
+                        </AlertTitle>
+                        {/* The reason in the text color, as red at this size is hard to read. */}
+                        <AlertDescription className="text-foreground">
+                            <p>{claimFailed.message}</p>
+                            <div className="mt-2 flex flex-wrap gap-2">
+                                {claimFailed.approvalUrl && (
+                                    <Button size="sm" asChild>
+                                        <a
+                                            href={claimFailed.approvalUrl}
+                                            target="_blank"
+                                            rel="noopener noreferrer"
+                                        >
+                                            <GitHubIcon className="size-4" />
+                                            Open GitHub
+                                        </a>
+                                    </Button>
+                                )}
+                                <Button size="sm" variant="outline" asChild>
+                                    <Link
+                                        href={claimUrl}
+                                        method="post"
+                                        as="button"
+                                    >
+                                        Try again
+                                    </Link>
+                                </Button>
+                            </div>
+                        </AlertDescription>
+                    </Alert>
+                )}
             </header>
 
             <div className="min-h-dvh">
diff --git a/resources/js/pages/privacy/show.tsx b/resources/js/pages/privacy/show.tsx
index 59c7621f8..4d3deb543 100644
--- a/resources/js/pages/privacy/show.tsx
+++ b/resources/js/pages/privacy/show.tsx
@@ -54,6 +54,16 @@ export default function Show() {
                                 listing, your public SSH key fingerprints, and
                                 who you follow and who follows you.
                             </>,
+                            <>
+                                <strong>
+                                    From GitHub, when you claim an
+                                    organization's page:
+                                </strong>{' '}
+                                whether you belong to that organization, asked
+                                once with your permission to read your
+                                organizations. Nothing else about them is kept,
+                                and your claim shows on the organization's page.
+                            </>,
                             <>
                                 <strong>
                                     From Apple, when you sign in with Apple in
diff --git a/resources/js/types/global.d.ts b/resources/js/types/global.d.ts
index 07c0226c7..e19525dba 100644
--- a/resources/js/types/global.d.ts
+++ b/resources/js/types/global.d.ts
@@ -21,6 +21,7 @@ declare module '@inertiajs/core' {
             submitted?: string;
             localSignIn?: boolean;
             signedUp?: boolean;
+            claimFailed?: { message: string; approvalUrl: string | null };
         };
         sharedPageProps: {
             name: string;
diff --git a/routes/web.php b/routes/web.php
index e6eca1793..4cf729966 100644
--- a/routes/web.php
+++ b/routes/web.php
@@ -74,6 +74,7 @@
 use App\Http\Controllers\OnboardingController;
 use App\Http\Controllers\OperationsController;
 use App\Http\Controllers\OperationsEventController;
+use App\Http\Controllers\OrganizationAdminController;
 use App\Http\Controllers\OrganizationController;
 use App\Http\Controllers\OrganizationMentionController;
 use App\Http\Controllers\OrganizationSitemapController;
@@ -323,6 +324,15 @@
     // Banned, where a banned user is sent from everywhere else...
     Route::get('banned', [BannedController::class, 'show'])->name('banned.show');
 
+    // Claiming an organization's page, which GitHub confirms the user belongs to...
+    Route::post('organizations/{organization}/claim', [OrganizationAdminController::class, 'create'])
+        ->whereUuid('organization')
+        ->middleware('throttle:10,1')
+        ->name('organization-admin.create');
+    Route::get('auth/github/callback/organizations', [OrganizationAdminController::class, 'store'])
+        ->middleware('throttle:10,1')
+        ->name('organization-admin.store');
+
     // Followers the viewer knows...
     Route::get('@{user:handle}/followers-you-know', [UserFollowersYouKnowController::class, 'index'])
         ->name('user-followers-you-know.index');
diff --git a/tests/Feature/Controllers/ExportControllerTest.php b/tests/Feature/Controllers/ExportControllerTest.php
index 23b4ff740..18ea6abda 100644
--- a/tests/Feature/Controllers/ExportControllerTest.php
+++ b/tests/Feature/Controllers/ExportControllerTest.php
@@ -16,6 +16,7 @@
 use App\Models\Notification;
 use App\Models\Poll;
 use App\Models\PollVote;
+use App\Models\Profile;
 use App\Models\SshKey;
 use App\Models\User;
 use App\Models\UserTimeout;
@@ -129,6 +130,7 @@
         'muting' => [],
         'blocking' => [],
         'dismissed_suggestions' => [],
+        'claimed_organizations' => [],
         'messages' => [],
         'remote_mutes' => [],
         'remote_pins' => [],
@@ -438,6 +440,23 @@
         );
 });
 
+it('exports the organizations the user claimed, first claim first, without their other admins', function (): void {
+    $this->freezeSecond();
+    $user = User::factory()->create();
+    $laravel = Profile::factory()->organization()->create(['handle' => 'laravel']);
+    $bref = Profile::factory()->organization()->create(['handle' => 'brefphp']);
+    $bref->admins()->attach($user->id, ['created_at' => now()->subDay()]);
+    $laravel->admins()->attach([$user->id => ['created_at' => now()], User::factory()->create()->id => ['created_at' => now()]]);
+
+    $response = $this->actingAs($user)->get(route('export'));
+    $data = json_decode($response->streamedContent(), true, flags: JSON_THROW_ON_ERROR);
+
+    expect($data['claimed_organizations'])->toBe([
+        ['handle' => 'brefphp', 'claimed_at' => now()->subDay()->toIso8601String()],
+        ['handle' => 'laravel', 'claimed_at' => now()->toIso8601String()],
+    ]);
+});
+
 it('exports the devices approved for the app, oldest first', function (): void {
     $user = User::factory()->create();
     $older = Device::factory()->for($user)->create(['name' => 'devnull on iPad', 'approved_at' => now()->subWeek(), 'last_used_at' => now()->subDay()]);
diff --git a/tests/Feature/Controllers/OrganizationAdminControllerTest.php b/tests/Feature/Controllers/OrganizationAdminControllerTest.php
new file mode 100644
index 000000000..9f83a5b1d
--- /dev/null
+++ b/tests/Feature/Controllers/OrganizationAdminControllerTest.php
@@ -0,0 +1,243 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\Profile;
+use App\Models\User;
+use Illuminate\Http\Client\Request;
+use Illuminate\Http\Client\RequestException;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Http;
+use Laravel\Socialite\Facades\Socialite;
+use Laravel\Socialite\Two\GithubProvider;
+use Laravel\Socialite\Two\InvalidStateException;
+use Laravel\Socialite\Two\User as GitHubUser;
+
+/**
+ * GitHub sends the user back as the given account, having granted the read:org scope.
+ */
+function fakeClaimingGitHubAccount(string $id): void
+{
+    $provider = Mockery::mock(GithubProvider::class);
+    $provider->shouldReceive('redirectUrl')->with(route('organization-admin.store'))->andReturnSelf();
+    $provider->shouldReceive('user')->andReturn(GitHubUser::fake(['id' => $id, 'nickname' => 'octocat', 'token' => 'claim-token']));
+
+    Socialite::shouldReceive('driver')->with('github')->andReturn($provider);
+}
+
+/**
+ * @param  array<string, mixed>  $membership
+ * @param  array<string, string>  $headers
+ */
+function fakeGitHubMembership(array $membership = [], int $status = 200, array $headers = []): void
+{
+    Http::fake([
+        'api.github.com/user/memberships/orgs/brefphp' => Http::response([
+            'state' => 'active',
+            'role' => 'member',
+            'organization' => ['id' => 45861341],
+            ...$membership,
+        ], $status, $headers),
+    ]);
+}
+
+/**
+ * @return array{0: User, 1: Profile}
+ */
+function claimingUserAndOrganization(): array
+{
+    return [
+        User::factory()->create(['github_id' => '720328']),
+        Profile::factory()->organization()->create(['github_id' => '45861341', 'handle' => 'brefphp']),
+    ];
+}
+
+it('asks github for the organizations of the user, coming back to the claim', function (): void {
+    config(['services.github.client_id' => 'client-id']);
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $response = $this->actingAs($user)->post(route('organization-admin.create', $organization));
+
+    $location = $response->assertRedirect()->headers->get('Location');
+    parse_str((string) parse_url((string) $location, PHP_URL_QUERY), $query);
+
+    expect($location)->toStartWith('https://github.com/login/oauth/authorize?')
+        ->and($query)->toMatchArray([
+            'client_id' => 'client-id',
+            'redirect_uri' => route('organization-admin.store'),
+            'scope' => 'user:email,read:org',
+        ]);
+    $response->assertSessionHas('claiming-organization', $organization->id);
+});
+
+it('leaves the page for github from the claim button', function (): void {
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->post(route('organization-admin.create', $organization), headers: ['X-Inertia' => 'true'])
+        ->assertConflict()
+        ->assertHeader('X-Inertia-Location');
+});
+
+it('only starts a claim from a form, so no other site can start one for the user', function (): void {
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)->get(route('organization-admin.create', $organization))
+        ->assertNotFound()
+        ->assertSessionMissing('claiming-organization');
+});
+
+it('only lets users claim organizations', function (): void {
+    $user = User::factory()->create();
+
+    $this->actingAs($user)->post(route('organization-admin.create', $user->profile))->assertNotFound();
+});
+
+it('asks guests to sign in first', function (): void {
+    $this->post(route('organization-admin.create', Profile::factory()->organization()->create()))->assertRedirect(route('home'));
+});
+
+it('makes a member of the organization on github an admin of its page', function (string $role): void {
+    fakeClaimingGitHubAccount('720328');
+    fakeGitHubMembership(['role' => $role]);
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store', ['code' => 'code', 'state' => 'state']))
+        ->assertRedirect('/@brefphp')
+        ->assertSessionMissing('claiming-organization')
+        ->assertInertiaFlash('toast', ['type' => 'success', 'message' => 'You are now an admin of @brefphp.']);
+
+    expect($organization->admins()->pluck('users.id')->all())->toBe([$user->id]);
+    Http::assertSent(fn (Request $request): bool => $request->hasHeader('Authorization', 'Bearer claim-token'));
+})->with(['admin', 'member']);
+
+it('keeps the first claim when the user claims again', function (): void {
+    fakeClaimingGitHubAccount('720328');
+    fakeGitHubMembership();
+    [$user, $organization] = claimingUserAndOrganization();
+    $claimedAt = now()->subWeek()->startOfSecond();
+    DB::table('organization_admins')->insert(['organization_id' => $organization->id, 'user_id' => $user->id, 'created_at' => $claimedAt]);
+
+    $this->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store'))
+        ->assertRedirect('/@brefphp');
+
+    expect(DB::table('organization_admins')->sole()->created_at)->toBe($claimedAt->toDateTimeString());
+});
+
+it('refuses users github does not say are members', function (array $membership, int $status): void {
+    fakeClaimingGitHubAccount('720328');
+    fakeGitHubMembership($membership, $status);
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store'))
+        ->assertRedirect('/@brefphp')
+        ->assertSessionMissing('claiming-organization')
+        ->assertInertiaFlash('claimFailed', ['message' => 'GitHub says you are not a member of @brefphp.', 'approvalUrl' => null]);
+
+    expect($organization->admins()->exists())->toBeFalse();
+})->with([
+    'not a member' => [['message' => 'Not Found'], 404],
+    'invited only' => [['state' => 'pending'], 200],
+    'a billing manager' => [['role' => 'billing_manager'], 200],
+    'of another organization since renamed' => [['organization' => ['id' => 1]], 200],
+]);
+
+it('says where to approve /dev/null when the organization hides its members from it', function (): void {
+    config(['services.github.client_id' => 'client-id']);
+    fakeClaimingGitHubAccount('720328');
+    fakeGitHubMembership(['message' => 'Although you appear to have the correct authorization credentials, the `brefphp` organization has enabled OAuth App access restrictions.'], 403);
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store'))
+        ->assertRedirect('/@brefphp')
+        ->assertInertiaFlash('claimFailed.approvalUrl', 'https://github.com/settings/connections/applications/client-id');
+
+    expect($organization->admins()->exists())->toBeFalse();
+});
+
+it('says where to sign in when the organization uses single sign-on', function (): void {
+    fakeClaimingGitHubAccount('720328');
+    fakeGitHubMembership(['message' => 'Resource protected by organization SAML enforcement. You must grant your OAuth token access to this organization.'], 403, ['X-GitHub-SSO' => 'required; url=https://github.com/orgs/brefphp/sso?authorization_request=abc']);
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store'))
+        ->assertRedirect('/@brefphp')
+        ->assertInertiaFlash('claimFailed', [
+            'message' => '@brefphp signs its members in with single sign-on. Sign in to @brefphp on GitHub, then try again.',
+            'approvalUrl' => 'https://github.com/orgs/brefphp/sso',
+        ]);
+
+    expect($organization->admins()->exists())->toBeFalse();
+});
+
+it('fails loudly when github fails', function (array $membership, int $status): void {
+    fakeClaimingGitHubAccount('720328');
+    fakeGitHubMembership($membership, $status);
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->withoutExceptionHandling()
+        ->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store'));
+})->with([
+    'down' => [[], 502],
+    'rate limited' => [['message' => 'API rate limit exceeded for user ID 720328.'], 403],
+])->throws(RequestException::class);
+
+it('refuses a github account other than the one the user signed in with', function (): void {
+    Http::fake();
+    fakeClaimingGitHubAccount('583231');
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store'))
+        ->assertRedirect('/@brefphp')
+        ->assertInertiaFlash('claimFailed.message', "GitHub is signed in as @octocat. Sign in there as @{$user->profile->handle} to claim this page.");
+
+    expect($organization->admins()->exists())->toBeFalse();
+    Http::assertNothingSent();
+});
+
+it('fails when the user denies access on github', function (): void {
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store', ['error' => 'access_denied']))
+        ->assertRedirect('/@brefphp')
+        ->assertInertiaFlash('claimFailed.message', 'GitHub was not asked about your organizations, so the page was not claimed.');
+});
+
+it('fails when the state does not match', function (): void {
+    $provider = Mockery::mock(GithubProvider::class);
+    $provider->shouldReceive('redirectUrl')->andReturnSelf();
+    $provider->shouldReceive('user')->andThrow(new InvalidStateException);
+    Socialite::shouldReceive('driver')->with('github')->andReturn($provider);
+    [$user, $organization] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->withSession(['claiming-organization' => $organization->id])
+        ->get(route('organization-admin.store'))
+        ->assertRedirect('/@brefphp')
+        ->assertInertiaFlash('claimFailed.message', 'Unable to claim this organization. Please try again.');
+});
+
+it('fails when no organization is being claimed', function (): void {
+    [$user] = claimingUserAndOrganization();
+
+    $this->actingAs($user)
+        ->get(route('organization-admin.store'))
+        ->assertRedirect(route('log.show', $user->log))
+        ->assertInertiaFlash('toast', ['type' => 'error', 'message' => 'Unable to claim this organization. Please try again.']);
+});
diff --git a/tests/Feature/Controllers/OrganizationControllerTest.php b/tests/Feature/Controllers/OrganizationControllerTest.php
index 90e732895..1981bbd6e 100644
--- a/tests/Feature/Controllers/OrganizationControllerTest.php
+++ b/tests/Feature/Controllers/OrganizationControllerTest.php
@@ -29,6 +29,23 @@
             ->missing('organization.github_synced_at'));
 });
 
+it('shows who claimed the organization, first claim first, and where to claim it', function (): void {
+    $organization = Profile::factory()->organization()->create(['handle' => 'laravel']);
+    $first = User::factory()->create();
+    $second = User::factory()->create();
+    $organization->admins()->attach([$second->id => ['created_at' => now()], $first->id => ['created_at' => now()->subDay()]]);
+
+    $this->get('/@laravel')
+        ->assertOk()
+        ->assertInertia(fn ($page) => $page
+            ->where('claimUrl', route('organization-admin.create', $organization))
+            ->where('admins.0.id', $first->id)
+            ->where('admins.0.handle', $first->profile->handle)
+            ->where('admins.1.id', $second->id)
+            ->missing('admins.0.pivot')
+            ->has('admins', 2));
+});
+
 it('shows guests the link preview of the organization', function (): void {
     $laravel = Profile::factory()->organization()->create([
         'handle' => 'laravel',
diff --git a/tests/Unit/Actions/DeleteOrganizationTest.php b/tests/Unit/Actions/DeleteOrganizationTest.php
new file mode 100644
index 000000000..81a730aac
--- /dev/null
+++ b/tests/Unit/Actions/DeleteOrganizationTest.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Actions\DeleteOrganization;
+use App\Models\Profile;
+use App\Models\User;
+use Illuminate\Support\Facades\DB;
+
+it('deletes an organization with its admins, keeping the users', function (): void {
+    $user = User::factory()->create();
+    $organization = Profile::factory()->organization()->create();
+    $kept = Profile::factory()->organization()->create();
+    $organization->admins()->attach($user->id, ['created_at' => now()]);
+    $kept->admins()->attach($user->id, ['created_at' => now()]);
+
+    resolve(DeleteOrganization::class)->handle($organization);
+
+    expect($organization->fresh())->toBeNull()
+        ->and($user->fresh())->not->toBeNull()
+        ->and(DB::table('organization_admins')->pluck('organization_id')->all())->toBe([$kept->id]);
+});
diff --git a/tests/Unit/Actions/DeleteUserTest.php b/tests/Unit/Actions/DeleteUserTest.php
index bf227ecb2..a50fe8abe 100644
--- a/tests/Unit/Actions/DeleteUserTest.php
+++ b/tests/Unit/Actions/DeleteUserTest.php
@@ -189,6 +189,17 @@
         ->and(PollVote::query()->sole()->is($keptVote))->toBeTrue();
 });
 
+it('erases the organizations a deleted user claimed, keeping their other admins', function (): void {
+    $user = User::factory()->create();
+    $other = User::factory()->create();
+    $organization = Profile::factory()->organization()->create();
+    $organization->admins()->attach([$user->id => ['created_at' => now()], $other->id => ['created_at' => now()]]);
+
+    resolve(DeleteUser::class)->handle($user);
+
+    expect($organization->admins()->pluck('users.id')->all())->toBe([$other->id]);
+});
+
 it('erases the devices of a deleted user', function (): void {
     $user = User::factory()->create();
     Device::factory()->for($user)->create();