diff --git a/system/Helpers/form_helper.php b/system/Helpers/form_helper.php
index b030b2f06009..465da04f6034 100644
--- a/system/Helpers/form_helper.php
+++ b/system/Helpers/form_helper.php
@@ -295,14 +295,14 @@ function form_dropdown($data = '', $options = [], $selected = [], $extra = ''):
         if ($selected === []) {
             $superglobals = service('superglobals');
             if (is_array($data)) {
-                $postValue = $superglobals->post($data['name'] ?? '');
+                $postValue = $superglobals->post(preg_replace('/\[\]$/', '', $data['name'] ?? ''));
                 if (isset($data['name']) && $postValue !== null) {
-                    $selected = [$postValue];
+                    $selected = is_array($postValue) ? $postValue : [$postValue];
                 }
             } else {
-                $postValue = $superglobals->post($data);
+                $postValue = $superglobals->post(preg_replace('/\[\]$/', '', $data));
                 if ($postValue !== null) {
-                    $selected = [$postValue];
+                    $selected = is_array($postValue) ? $postValue : [$postValue];
                 }
             }
         }
diff --git a/tests/system/Helpers/FormHelperTest.php b/tests/system/Helpers/FormHelperTest.php
index 7ed8c8668123..bfd3d12e0efe 100644
--- a/tests/system/Helpers/FormHelperTest.php
+++ b/tests/system/Helpers/FormHelperTest.php
@@ -588,6 +588,36 @@ public function testFormDropdownInferred(): void
         service('superglobals')->unsetPost('cars');
     }
 
+    public function testFormDropdownInferredArray(): void
+    {
+        $options = [
+            'Swedish Cars' => [
+                'volvo' => 'Volvo',
+                'saab'  => 'Saab',
+            ],
+            'German Cars' => [
+                'mercedes' => 'Mercedes',
+                'audi'     => 'Audi',
+            ],
+        ];
+        $expected = <<<EOH
+            <select name="cars" multiple="multiple">
+            <optgroup label="Swedish Cars">
+            <option value="volvo" selected="selected">Volvo</option>
+            <option value="saab">Saab</option>
+            </optgroup>
+            <optgroup label="German Cars">
+            <option value="mercedes">Mercedes</option>
+            <option value="audi" selected="selected">Audi</option>
+            </optgroup>
+            </select>\n
+            EOH;
+        service('superglobals')->setPost('cars', ['volvo', 'audi']);
+        $this->assertSame($expected, form_dropdown('cars', $options));
+        $this->assertSame($expected, form_dropdown(['name' => 'cars'], $options));
+        service('superglobals')->unsetPost('cars');
+    }
+
     public function testFormDropdownWithSelectedAttribute(): void
     {
         $expected = <<<'EOH'
@@ -684,6 +714,29 @@ public function testFormMultiselectArrayData(): void
         $this->assertSame($expected, form_multiselect($data));
     }
 
+    public function testFormMultiselectInferred(): void
+    {
+        $expected = <<<EOH
+            <select name="shirts[]"  multiple="multiple">
+            <option value="small">Small Shirt</option>
+            <option value="med" selected="selected">Medium Shirt</option>
+            <option value="large" selected="selected">Large Shirt</option>
+            <option value="xlarge">Extra Large Shirt</option>
+            </select>\n
+            EOH;
+        $options = [
+            'small'  => 'Small Shirt',
+            'med'    => 'Medium Shirt',
+            'large'  => 'Large Shirt',
+            'xlarge' => 'Extra Large Shirt',
+        ];
+
+        service('superglobals')->setPost('shirts', ['med', 'large']);
+        $this->assertSame($expected, form_multiselect('shirts[]', $options));
+        $this->assertSame($expected, form_multiselect(['name' => 'shirts[]', 'options' => $options]));
+        service('superglobals')->unsetPost('shirts');
+    }
+
     public function testFormFieldset(): void
     {
         $expected = <<<EOH