diff --git a/cms/css/editor.css b/cms/css/editor.css
index 415cee1..d251e0c 100644
--- a/cms/css/editor.css
+++ b/cms/css/editor.css
@@ -435,6 +435,7 @@ body {
     margin-left: 10px; padding: 2px 8px; border-radius: 999px; font-size: 11px; font-weight: 600;
     background: #fff3d6; color: #8a5a00; border: 1px solid #f0d58a;
 }
+.badge-locked { background: #fde2e1; color: #8a1f1f; border-color: #f3b4b2; }
 @media (max-width: 700px) { #fileList .page-title, #fileList th:nth-child(2), #fileList .page-date, #fileList th:nth-child(3) { display: none; } }
 
 /* Site scan progress bar and file count. */
diff --git a/cms/js/cms.js b/cms/js/cms.js
index a89a23d..e8c9bfd 100644
--- a/cms/js/cms.js
+++ b/cms/js/cms.js
@@ -447,6 +447,7 @@
                 const name = $('<td class="page-cell">').append(docIcon());
                 $('<button type="button" class="page-open">').text(page.name).appendTo(name);
                 if (page.draft) $('<span class="badge-draft">').text(page.pending ? 'New - unpublished' : 'Draft').appendTo(name);
+                if (page.locked) $('<span class="badge-draft badge-locked">').text('Locked').appendTo(name);
                 row.append(name, $('<td class="page-title">').text(page.title), $('<td class="page-date">').text(formatDate(page.modified)));
                 const actions = $('<td class="row-actions manage-col">').toggle(permissions.manage).appendTo(row);
                 if (permissions.manage && page.pending) {
@@ -456,6 +457,8 @@
                         $('<button type="button">').text(action[0]).toggleClass('danger-text', action[1] === 'delete')
                             .on('click', function (event) { event.stopPropagation(); action[1] === 'template' ? setPageTemplate(page.url, true) : managePage(action[1], page.url); }).appendTo(actions);
                     });
+                    $('<button type="button">').text(page.locked ? 'Unlock' : 'Lock')
+                        .on('click', function (event) { event.stopPropagation(); lockPage(page.url, !page.locked); }).appendTo(actions);
                 }
                 body.append(row);
             });
@@ -638,6 +641,13 @@
         } catch (error) { showMessage(error.message, 'error'); }
     }
 
+    async function lockPage(uri, on) {
+        try {
+            showMessage((await api('lockPage', {uri: uri, value: on ? '1' : '0'}, 'POST')).message, 'success');
+            openPages();
+        } catch (error) { showMessage(error.message, 'error'); }
+    }
+
     async function discardNewPage(uri) {
         if (!window.confirm('Discard this unpublished page and its draft? This cannot be undone.')) return;
         try {
diff --git a/cms/src/NeoCMS/CMSController.php b/cms/src/NeoCMS/CMSController.php
index cb101ac..270d429 100644
--- a/cms/src/NeoCMS/CMSController.php
+++ b/cms/src/NeoCMS/CMSController.php
@@ -139,6 +139,7 @@ final class CMSController
     {
         $this->requirePost('publish');
         $uri = $this->requiredPost('uri');
+        $this->assertNotLockedForEditor($uri);
         $content = $this->requiredContentPost('content');
         $this->publishContent($uri, $content, 'Published page');
         $this->deleteDraft($uri);
@@ -150,6 +151,7 @@ final class CMSController
     {
         $this->requirePost('draft');
         $uri = $this->requiredPost('uri');
+        $this->assertNotLockedForEditor($uri);
         $content = $this->requiredContentPost('content');
         $this->storeDraft($uri, $content);
         $this->activity('Saved draft', $uri);
@@ -188,6 +190,7 @@ final class CMSController
     {
         $this->requirePost('schedule');
         $uri = $this->requiredPost('uri');
+        $this->assertNotLockedForEditor($uri);
         $content = $this->requiredContentPost('content');
         $this->assertPublishable($uri);
         $publishAt = new \DateTimeImmutable($this->requiredPost('publish_at'));
@@ -290,6 +293,25 @@ final class CMSController
         $this->respond(['message' => $on ? 'Template created. It is now available in New Page.' : 'Page is no longer a template']);
     }
 
+    /** Lock a page against editor changes, or unlock it; administrators only. */
+    private function lockPageAction(): void
+    {
+        $this->requirePost('manage');
+        $uri = $this->paths->normaliseUri($this->requiredPost('uri'));
+        $this->paths->existing($uri);
+        $on = ($_POST['value'] ?? '') === '1';
+        $this->store->update('pagelocks', function (array $locked) use ($uri, $on) {
+            if ($on) {
+                $locked[$uri] = ['user' => $this->user(), 'created' => date(DATE_ATOM)];
+            } else {
+                unset($locked[$uri]);
+            }
+            return $locked;
+        });
+        $this->activity($on ? 'Locked page' : 'Unlocked page', $uri);
+        $this->respond(['message' => $on ? 'Page locked. Editors can no longer edit it.' : 'Page unlocked']);
+    }
+
     /**
      * Start a new page from a template. Nothing is written to the site: the page exists only as a private draft
      * and a pending record until it is first published, so it is not visible on the front end before then.
@@ -458,6 +480,10 @@ final class CMSController
                 unset($marked[$sourceUri]);
                 return $marked;
             });
+            $this->store->update('pagelocks', function (array $locked) use ($sourceUri) {
+                unset($locked[$sourceUri]);
+                return $locked;
+            });
             $this->activity('Deleted page', $sourceUri);
             $this->respond(['message' => 'Page deleted']);
             return;
@@ -482,6 +508,13 @@ final class CMSController
                 }
                 return $marked;
             });
+            $this->store->update('pagelocks', function (array $locked) use ($sourceUri, $targetUri) {
+                if (isset($locked[$sourceUri])) {
+                    $locked[$targetUri] = $locked[$sourceUri];
+                    unset($locked[$sourceUri]);
+                }
+                return $locked;
+            });
         }
         $this->activity(ucfirst($operation) . 'd page', $sourceUri . ' -> ' . $targetUri);
         $this->respond(['message' => 'Page ' . $operation . 'd', 'url' => $targetUri]);
@@ -491,6 +524,7 @@ final class CMSController
     private function getPagesAction(): void
     {
         $drafts = $this->store->read('drafts');
+        $locked = $this->store->read('pagelocks');
         $pages = [];
         foreach ($this->paths->files() as $path) {
             $uri = $this->paths->uriFor($path);
@@ -504,10 +538,11 @@ final class CMSController
                 'title' => $this->extractTitle($html),
                 'modified' => date(DATE_ATOM, filemtime($path)),
                 'draft' => isset($drafts[$uri]),
+                'locked' => isset($locked[$uri]),
             ];
         }
         foreach ($this->store->read('newpages') as $uri => $entry) {
-            $pages[] = ['name' => $uri, 'url' => $uri, 'title' => (string) ($entry['title'] ?? ''), 'modified' => $entry['created'] ?? date(DATE_ATOM), 'draft' => true, 'pending' => true];
+            $pages[] = ['name' => $uri, 'url' => $uri, 'title' => (string) ($entry['title'] ?? ''), 'modified' => $entry['created'] ?? date(DATE_ATOM), 'draft' => true, 'pending' => true, 'locked' => isset($locked[$uri])];
         }
         usort($pages, fn(array $a, array $b) => strcmp($a['name'], $b['name']));
         $this->respond($pages);
@@ -1352,6 +1387,17 @@ final class CMSController
         }
     }
 
+    /** Refuse editors (never administrators) write access to a page an administrator has locked. */
+    private function assertNotLockedForEditor(string $uri): void
+    {
+        if ($this->authentication->can('manage')) {
+            return;
+        }
+        if (isset($this->store->read('pagelocks')[$this->paths->normaliseUri($uri)])) {
+            throw new \RuntimeException('This page is locked by an administrator and cannot be edited.');
+        }
+    }
+
     /** Return a required string POST field or raise a client-facing validation error. */
     private function requiredPost(string $key): string
     {
diff --git a/docs/ARCHITECTURE.md b/docs/ARCHITECTURE.md
index 807e5ad..6cd224a 100644
--- a/docs/ARCHITECTURE.md
+++ b/docs/ARCHITECTURE.md
@@ -58,6 +58,7 @@ Published content stays in the web document root. NeoCMS stores supporting data
 | `menus.json` | Named menus: `{key: {items: [{label, url, parent}], updated, title?}}`; seeded by the site scan, never created by the CMS. |
 | `newpages.json` | Pending (unpublished) pages: title, chosen menu, template, author, created. |
 | `pagetemplates.json` | Pages offered as templates in the New page section of Pages. |
+| `pagelocks.json` | Pages an administrator has locked against editor changes. |
 | `users.json` | CMS-created accounts and profile overlays for config accounts (`{users: {...}, profiles: {...}}`). |
 | `media.json` | Per-file description (alt text or link text), original filename, and uploader. |
 | `activity.json` | The latest 250 dashboard activity entries. |
diff --git a/tests/run.php b/tests/run.php
index 6a2d6a1..59ce40f 100644
--- a/tests/run.php
+++ b/tests/run.php
@@ -219,10 +219,15 @@ try {
 
     // Administrator page operations must support duplicate, rename, delete, and restoration.
     $request('page', ['operation' => 'duplicate', 'uri' => '/index.html', 'target' => '/copy.html'], 'POST');
+    assertTrue(!isset((new NeoCMS\FileStore($data))->read('pagelocks')['/copy.html']), 'Duplicating a page copied its lock');
+    $request('lockPage', ['uri' => '/copy.html', 'value' => '1'], 'POST');
     $request('page', ['operation' => 'rename', 'uri' => '/copy.html', 'target' => '/renamed.html'], 'POST');
     assertTrue(is_file($root . '/renamed.html'), 'Duplicate or rename failed');
+    $locksAfterRename = (new NeoCMS\FileStore($data))->read('pagelocks');
+    assertTrue(!isset($locksAfterRename['/copy.html']) && isset($locksAfterRename['/renamed.html']), 'Renaming a page did not move its lock entry');
     $request('page', ['operation' => 'delete', 'uri' => '/renamed.html'], 'POST');
     assertTrue(!is_file($root . '/renamed.html'), 'Page delete failed');
+    assertTrue(!isset((new NeoCMS\FileStore($data))->read('pagelocks')['/renamed.html']), 'Deleting a page left a stale lock entry');
     assertTrue(in_array('/renamed.html', array_column($request('dashboard')['deleted'], 'uri'), true), 'Deleted page was not listed on the dashboard');
     $deletedRevisions = $request('revisions', ['uri' => '/renamed.html']);
     $request('restoreRevision', ['id' => $deletedRevisions[0]['id']], 'POST');
@@ -536,6 +541,15 @@ try {
         assertTrue(($as('ed1', $action, $params)['error'] ?? '') === 'Your role cannot perform this action', "An editor could run {$action}");
     }
 
+    // ---- Page locks: administrators toggle, only editors are blocked from editing ----
+    $ok($as('tester', 'lockPage', ['uri' => '/index.html', 'value' => '1']), 'Admin could not lock a page');
+    $pages = $as('tester', 'getPages', [], 'GET');
+    assertTrue((array_column($pages, 'locked', 'url'))['/index.html'] === true, 'Locked page was not reported as locked');
+    $err($as('ed1', 'saveDraft', ['uri' => '/index.html', 'content' => '<main class="cms-content">x</main>']), 'Editor saved a draft on a locked page');
+    $ok($as('tester', 'saveDraft', ['uri' => '/index.html', 'content' => '<main class="cms-content">x</main>']), 'Administrator was blocked by their own lock');
+    $ok($as('tester', 'lockPage', ['uri' => '/index.html', 'value' => '0']), 'Admin could not unlock a page');
+    $ok($as('ed1', 'saveDraft', ['uri' => '/index.html', 'content' => '<main class="cms-content">x</main>']), 'Editor still blocked after unlock');
+
     // Self-service: display name freely, email and password need the current password.
     $ok($as('ed1', 'saveProfile', ['name' => 'Edward Example', 'email' => 'ed@example.com']), 'Editor could not change their display name');
     $err($as('ed1', 'saveProfile', ['name' => 'Edward', 'email' => 'new@example.com']), 'Email changed without the current password');