diff --git a/.changeset/preact-retry-on-mount-throw-on-error.md b/.changeset/preact-retry-on-mount-throw-on-error.md
new file mode 100644
index 00000000000..21a7fd14a04
--- /dev/null
+++ b/.changeset/preact-retry-on-mount-throw-on-error.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/preact-query': patch
+---
+
+Evaluate a function-form `throwOnError` against the actual query error before disabling `retryOnMount` (port of #9338), so errored queries whose `throwOnError` returns `false` are retried on mount again.
diff --git a/packages/preact-query/src/__tests__/useQuery.test.tsx b/packages/preact-query/src/__tests__/useQuery.test.tsx
index 3a36725ff09..db1971ec4aa 100644
--- a/packages/preact-query/src/__tests__/useQuery.test.tsx
+++ b/packages/preact-query/src/__tests__/useQuery.test.tsx
@@ -6740,4 +6740,171 @@ describe('useQuery', () => {
     expect(rendered.getByTestId('data')).toHaveTextContent('undefined')
     expect(queryFn).toHaveBeenCalledTimes(0)
   })
+  it('should retry on mount when throwOnError returns false', async () => {
+    const key = queryKey()
+    let fetchCount = 0
+    const queryFn = vi.fn().mockImplementation(() => {
+      fetchCount++
+      console.log(`Fetching... (attempt ${fetchCount})`)
+      return Promise.reject(new Error('Simulated 500 error'))
+    })
+
+    function Component() {
+      const { status, error } = useQuery({
+        queryKey: key,
+        queryFn,
+        throwOnError: () => false,
+        retryOnMount: () => true,
+        staleTime: Infinity,
+        retry: false,
+      })
+
+      return (
+        <div>
+          <div data-testid="status">{status}</div>
+          {error && <div data-testid="error">{error.message}</div>}
+        </div>
+      )
+    }
+
+    const rendered1 = renderWithClient(queryClient, <Component />)
+    await vi.advanceTimersByTimeAsync(0)
+    expect(rendered1.getByTestId('status')).toHaveTextContent('error')
+    expect(rendered1.getByTestId('error')).toHaveTextContent(
+      'Simulated 500 error',
+    )
+    expect(fetchCount).toBe(1)
+    rendered1.unmount()
+
+    const initialFetchCount = fetchCount
+
+    const rendered2 = renderWithClient(queryClient, <Component />)
+    await vi.advanceTimersByTimeAsync(0)
+    expect(rendered2.getByTestId('status')).toHaveTextContent('error')
+
+    expect(fetchCount).toBe(initialFetchCount + 1)
+    expect(queryFn).toHaveBeenCalledTimes(2)
+  })
+
+  it('should not retry on mount when throwOnError function returns true', async () => {
+    const key = queryKey()
+    let fetchCount = 0
+    const queryFn = vi.fn().mockImplementation(() => {
+      fetchCount++
+      console.log(`Fetching... (attempt ${fetchCount})`)
+      return Promise.reject(new Error('Simulated 500 error'))
+    })
+
+    function Component() {
+      const { status, error } = useQuery({
+        queryKey: key,
+        queryFn,
+        throwOnError: () => true,
+        retryOnMount: () => true,
+        staleTime: Infinity,
+        retry: false,
+      })
+
+      return (
+        <div>
+          <div data-testid="status">{status}</div>
+          {error && <div data-testid="error">{error.message}</div>}
+        </div>
+      )
+    }
+
+    const rendered1 = renderWithClient(
+      queryClient,
+      <ErrorBoundary
+        fallbackRender={({ error }) => (
+          <div>
+            <div data-testid="status">error</div>
+            <div data-testid="error">{error?.message}</div>
+          </div>
+        )}
+      >
+        <Component />
+      </ErrorBoundary>,
+    )
+    await vi.advanceTimersByTimeAsync(0)
+    expect(rendered1.getByTestId('status')).toHaveTextContent('error')
+    expect(rendered1.getByTestId('error')).toHaveTextContent(
+      'Simulated 500 error',
+    )
+    expect(fetchCount).toBe(1)
+
+    rendered1.unmount()
+
+    const initialFetchCount = fetchCount
+
+    const rendered2 = renderWithClient(
+      queryClient,
+      <ErrorBoundary
+        fallbackRender={({ error }) => (
+          <div>
+            <div data-testid="status">error</div>
+            <div data-testid="error">{error?.message}</div>
+          </div>
+        )}
+      >
+        <Component />
+      </ErrorBoundary>,
+    )
+    await vi.advanceTimersByTimeAsync(0)
+    expect(rendered2.getByTestId('status')).toHaveTextContent('error')
+
+    // Should not retry because throwOnError returns true
+    expect(fetchCount).toBe(initialFetchCount)
+    expect(queryFn).toHaveBeenCalledTimes(1)
+  })
+
+  it('should handle throwOnError function based on actual error state', async () => {
+    const key = queryKey()
+    let fetchCount = 0
+    const queryFn = vi.fn().mockImplementation(() => {
+      fetchCount++
+      console.log(`Fetching... (attempt ${fetchCount})`)
+      return Promise.reject(new Error('Simulated 500 error'))
+    })
+
+    function Component() {
+      const { status, error } = useQuery({
+        queryKey: key,
+        queryFn,
+        throwOnError: (error) => error.message.includes('404'),
+        retryOnMount: true,
+        staleTime: Infinity,
+        retry: false,
+      })
+
+      return (
+        <div>
+          <div data-testid="status">{status}</div>
+          {error && <div data-testid="error">{error.message}</div>}
+        </div>
+      )
+    }
+
+    const rendered1 = renderWithClient(queryClient, <Component />)
+
+    await vi.advanceTimersByTimeAsync(0)
+    expect(rendered1.getByTestId('status')).toHaveTextContent('error')
+    expect(rendered1.getByTestId('error')).toHaveTextContent(
+      'Simulated 500 error',
+    )
+    expect(fetchCount).toBe(1)
+
+    rendered1.unmount()
+
+    const initialFetchCount = fetchCount
+
+    const rendered2 = renderWithClient(queryClient, <Component />)
+
+    await vi.advanceTimersByTimeAsync(0)
+    expect(rendered2.getByTestId('status')).toHaveTextContent('error')
+
+    // Should retry because throwOnError returns false (500 error doesn't include '404')
+    expect(fetchCount).toBe(initialFetchCount + 1)
+    expect(queryFn).toHaveBeenCalledTimes(2)
+  })
 })
diff --git a/packages/preact-query/src/errorBoundaryUtils.ts b/packages/preact-query/src/errorBoundaryUtils.ts
index 0b3d561fea6..86fbccd29f1 100644
--- a/packages/preact-query/src/errorBoundaryUtils.ts
+++ b/packages/preact-query/src/errorBoundaryUtils.ts
@@ -25,11 +25,17 @@ export const ensurePreventErrorBoundaryRetry = <
     TQueryKey
   >,
   errorResetBoundary: QueryErrorResetBoundaryValue,
+  query: Query<TQueryFnData, TError, TQueryData, TQueryKey> | undefined,
 ) => {
+  const throwOnError =
+    query?.state.error && typeof options.throwOnError === 'function'
+      ? shouldThrowError(options.throwOnError, [query.state.error, query])
+      : options.throwOnError
+
   if (
     options.suspense ||
-    options.throwOnError ||
-    options.experimental_prefetchInRender
+    options.experimental_prefetchInRender ||
+    throwOnError
   ) {
     // Prevent retrying failed query if the error boundary has not been reset yet
     if (!errorResetBoundary.isReset()) {
diff --git a/packages/preact-query/src/useBaseQuery.ts b/packages/preact-query/src/useBaseQuery.ts
index 05ce46e7f6e..ec820b7586b 100644
--- a/packages/preact-query/src/useBaseQuery.ts
+++ b/packages/preact-query/src/useBaseQuery.ts
@@ -58,6 +58,15 @@ export function useBaseQuery<
     defaultedOptions,
   )
 
+  const query = client
+    .getQueryCache()
+    .get<
+      TQueryFnData,
+      TError,
+      TQueryData,
+      TQueryKey
+    >(defaultedOptions.queryHash)
+
   if (process.env.NODE_ENV !== 'production') {
     if (!defaultedOptions.queryFn) {
       console.error(
@@ -72,7 +81,7 @@ export function useBaseQuery<
     : 'optimistic'
 
   ensureSuspenseTimers(defaultedOptions)
-  ensurePreventErrorBoundaryRetry(defaultedOptions, errorResetBoundary)
+  ensurePreventErrorBoundaryRetry(defaultedOptions, errorResetBoundary, query)
 
   useClearResetErrorBoundary(errorResetBoundary)
 
@@ -126,14 +135,7 @@ export function useBaseQuery<
       result,
       errorResetBoundary,
       throwOnError: defaultedOptions.throwOnError,
-      query: client
-        .getQueryCache()
-        .get<
-          TQueryFnData,
-          TError,
-          TQueryData,
-          TQueryKey
-        >(defaultedOptions.queryHash),
+      query,
       suspense: defaultedOptions.suspense,
     })
   ) {
@@ -154,7 +156,7 @@ export function useBaseQuery<
       ? // Fetch immediately on render in order to ensure `.promise` is resolved even if the component is unmounted
         fetchOptimistic(defaultedOptions, observer, errorResetBoundary)
       : // subscribe to the "cache promise" so that we can finalize the currentThenable once data comes in
-        client.getQueryCache().get(defaultedOptions.queryHash)?.promise
+        query?.promise
 
     promise?.catch(noop).finally(() => {
       // `.updateResult()` will trigger `.#currentThenable` to finalize
diff --git a/packages/preact-query/src/useQueries.ts b/packages/preact-query/src/useQueries.ts
index 7e30658b843..dac252d0109 100644
--- a/packages/preact-query/src/useQueries.ts
+++ b/packages/preact-query/src/useQueries.ts
@@ -241,9 +241,10 @@ export function useQueries<
     [queries, client, isRestoring],
   )
 
-  defaultedQueries.forEach((query) => {
-    ensureSuspenseTimers(query)
-    ensurePreventErrorBoundaryRetry(query, errorResetBoundary)
+  defaultedQueries.forEach((queryOptions) => {
+    ensureSuspenseTimers(queryOptions)
+    const query = client.getQueryCache().get(queryOptions.queryHash)
+    ensurePreventErrorBoundaryRetry(queryOptions, errorResetBoundary, query)
   })
 
   useClearResetErrorBoundary(errorResetBoundary)