diff --git a/core/modules/layout_builder/layout_builder.services.yml b/core/modules/layout_builder/layout_builder.services.yml
index 6e94ed74d2..6984c9b040 100644
--- a/core/modules/layout_builder/layout_builder.services.yml
+++ b/core/modules/layout_builder/layout_builder.services.yml
@@ -45,6 +45,11 @@ services:
     arguments: ['@current_user']
     tags:
       - { name: event_subscriber }
+  layout_builder.block_component_preview_form_replace_subscriber:
+    class: Drupal\layout_builder\EventSubscriber\BlockComponentPreviewFormReplace
+    arguments: ['@renderer']
+    tags:
+      - { name: event_subscriber }
   logger.channel.layout_builder:
     parent: logger.channel_base
     arguments: ['layout_builder']
diff --git a/core/modules/layout_builder/src/EventSubscriber/BlockComponentPreviewFormReplace.php b/core/modules/layout_builder/src/EventSubscriber/BlockComponentPreviewFormReplace.php
new file mode 100644
index 0000000000..3f40d67dce
--- /dev/null
+++ b/core/modules/layout_builder/src/EventSubscriber/BlockComponentPreviewFormReplace.php
@@ -0,0 +1,108 @@
+<?php
+
+namespace Drupal\layout_builder\EventSubscriber;
+
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Render\RendererInterface;
+use Drupal\layout_builder\Event\SectionComponentBuildRenderArrayEvent;
+use Drupal\layout_builder\LayoutBuilderEvents;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Replaces form elements with divs in layout builder previews.
+ *
+ * Because layout builder's preview interface is wrapped in a form, any block
+ * component that also has a form creates invalid HTML (a form inside a form)
+ * and prevents the outer form from being submitted correctly.
+ *
+ * This subscriber scans for forms in blocks and changes the HTML element
+ * to a div, which allows the outer form to work correctly.
+ *
+ * @internal
+ *   Tagged services are internal.
+ */
+class BlockComponentPreviewFormReplace implements EventSubscriberInterface {
+
+  /**
+   * The core renderer service.
+   *
+   * @var \Drupal\Core\Render\RendererInterface
+   */
+  protected $renderer;
+
+  /**
+   * Creates a BlockComponentRenderArray object.
+   *
+   * @param \Drupal\Core\Render\RendererInterface $renderer
+   *  The core renderer service.
+   */
+  public function __construct(RendererInterface $renderer) {
+    $this->renderer = $renderer;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    // Very low priority - we want this to occur last since we perform early
+    // rendering of block components and want the most complete render array
+    // before doing that.
+    $events[LayoutBuilderEvents::SECTION_COMPONENT_BUILD_RENDER_ARRAY] = ['onBuildRender', -1000];
+    return $events;
+  }
+
+  /**
+   * Change forms to divs if in layout builder's preview mode.
+   *
+   * @param \Drupal\layout_builder\Event\SectionComponentBuildRenderArrayEvent $event
+   *   The section component render event.
+   */
+  public function onBuildRender(SectionComponentBuildRenderArrayEvent $event) {
+    $build = $event->getBuild();
+    if ($event->inPreview() && isset($build['content']) && is_array($build['content'])) {
+      $build['content'] = $this->convertFormsToDiv($build['content']);
+      $event->setBuild($build);
+    }
+  }
+
+  /**
+   * Convert form tags to div when displayed in the Layout Builder UI form.
+   *
+   * @param array $content
+   *   The render array of the block.
+   */
+  protected function convertFormsToDiv(array $content) {
+    // Render the block content early so we can parse the HTML.
+    // We keep an original copy around so we can return that if no forms are
+    // found. This allows us to only perform the early rendering when
+    // necessary.
+    $orginal_content = $content;
+    $markup = $this->renderer->render($content);
+    $html = Html::load((string) $markup);
+
+    $forms = $html->getElementsByTagName('form');
+    if ($forms->length) {
+      // Iteratve over each form and swap the form element with a div.
+      while ($form = $forms->item($forms->length - 1)) {
+        $form_children = [];
+        foreach ($form->childNodes as $form_child) {
+          $form_children[] = $form_child;
+        }
+        $replacement_div = $html->createElement('div');
+        foreach ($form_children as $form_child) {
+          $replacement_div->appendChild($form_child);
+        }
+        foreach ($form->attributes as $form_attr_name => $form_attr) {
+          $replacement_div->setAttribute($form_attr_name, $form_attr->nodeValue);
+        }
+        $form->parentNode->replaceChild($replacement_div, $form);
+      }
+      $content['#markup'] = $html->saveHTML($html->getElementsByTagName('body')->item(0));
+      return $content;
+    }
+    else {
+      return $orginal_content;
+    }
+  }
+
+}