diff --git a/resources/js/components/navigation/View.vue b/resources/js/components/navigation/View.vue
index c741272f5b..4681af6597 100644
--- a/resources/js/components/navigation/View.vue
+++ b/resources/js/components/navigation/View.vue
@@ -421,6 +421,10 @@ export default {
         },
 
         treeSaved(response) {
+            if (! response.data.saved) {
+                return this.$toast.error(`Couldn't save tree`)
+            }
+
             this.replaceGeneratedIds(response.data.generatedIds);
 
             this.changed = false;
diff --git a/resources/js/components/structures/PageTree.vue b/resources/js/components/structures/PageTree.vue
index 2170ee128d..a9c572dacc 100644
--- a/resources/js/components/structures/PageTree.vue
+++ b/resources/js/components/structures/PageTree.vue
@@ -207,6 +207,10 @@ export default {
             };
 
             return this.$axios.patch(this.submitUrl, payload).then(response => {
+                if (! response.data.saved) {
+                    return this.$toast.error(`Couldn't save tree`)
+                }
+
                 this.$emit('saved', response);
                 this.$toast.success(__('Saved'));
                 this.initialPages = this.pages;
diff --git a/src/Events/CollectionTreeSaving.php b/src/Events/CollectionTreeSaving.php
new file mode 100644
index 0000000000..02537e2f81
--- /dev/null
+++ b/src/Events/CollectionTreeSaving.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Statamic\Events;
+
+class CollectionTreeSaving extends Event
+{
+    public $tree;
+
+    public function __construct($tree)
+    {
+        $this->tree = $tree;
+    }
+
+    /**
+     * Dispatch the event with the given arguments, and halt on first non-null listener response.
+     *
+     * @return mixed
+     */
+    public static function dispatch()
+    {
+        return event(new static(...func_get_args()), [], true);
+    }
+}
diff --git a/src/Events/NavTreeSaving.php b/src/Events/NavTreeSaving.php
new file mode 100644
index 0000000000..8b1f05b7cb
--- /dev/null
+++ b/src/Events/NavTreeSaving.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Statamic\Events;
+
+class NavTreeSaving extends Event
+{
+    public $tree;
+
+    public function __construct($tree)
+    {
+        $this->tree = $tree;
+    }
+
+    /**
+     * Dispatch the event with the given arguments, and halt on first non-null listener response.
+     *
+     * @return mixed
+     */
+    public static function dispatch()
+    {
+        return event(new static(...func_get_args()), [], true);
+    }
+}
diff --git a/src/Http/Controllers/CP/Collections/CollectionTreeController.php b/src/Http/Controllers/CP/Collections/CollectionTreeController.php
index 5c848b4e19..fb8acc556c 100644
--- a/src/Http/Controllers/CP/Collections/CollectionTreeController.php
+++ b/src/Http/Controllers/CP/Collections/CollectionTreeController.php
@@ -46,7 +46,9 @@ public function update(Request $request, $collection)
         // if somehow the root would end up having child pages, which isn't allowed.
         $contents = $structure->validateTree($contents, $request->site);
 
-        $tree->tree($contents)->save();
+        return [
+            'saved' => $tree->tree($contents)->save(),
+        ];
     }
 
     private function toTree($items)
diff --git a/src/Http/Controllers/CP/Navigation/NavigationTreeController.php b/src/Http/Controllers/CP/Navigation/NavigationTreeController.php
index 7cecc54201..67c9a2f477 100644
--- a/src/Http/Controllers/CP/Navigation/NavigationTreeController.php
+++ b/src/Http/Controllers/CP/Navigation/NavigationTreeController.php
@@ -51,10 +51,11 @@ public function update(Request $request, $nav)
 
         $tree = $this->reorderTree($request->pages);
 
-        $nav->in($request->site)->tree($tree)->save();
+        $saved = $nav->in($request->site)->tree($tree)->save();
 
         return [
             'generatedIds' => $this->generatedIds,
+            'saved' => $saved,
         ];
     }
 
diff --git a/src/Structures/CollectionTree.php b/src/Structures/CollectionTree.php
index 3af66f3865..6213dd3c5b 100644
--- a/src/Structures/CollectionTree.php
+++ b/src/Structures/CollectionTree.php
@@ -7,6 +7,7 @@
 use Statamic\Contracts\Structures\CollectionTreeRepository;
 use Statamic\Events\CollectionTreeDeleted;
 use Statamic\Events\CollectionTreeSaved;
+use Statamic\Events\CollectionTreeSaving;
 use Statamic\Facades\Blink;
 use Statamic\Facades\Collection;
 use Statamic\Facades\Site;
@@ -45,6 +46,11 @@ protected function dispatchSavedEvent()
         CollectionTreeSaved::dispatch($this);
     }
 
+    protected function dispatchSavingEvent()
+    {
+        return CollectionTreeSaving::dispatch($this);
+    }
+
     protected function dispatchDeletedEvent()
     {
         CollectionTreeDeleted::dispatch($this);
diff --git a/src/Structures/NavTree.php b/src/Structures/NavTree.php
index 3dd7caba93..0faa887696 100644
--- a/src/Structures/NavTree.php
+++ b/src/Structures/NavTree.php
@@ -7,6 +7,7 @@
 use Statamic\Contracts\Structures\NavTreeRepository;
 use Statamic\Events\NavTreeDeleted;
 use Statamic\Events\NavTreeSaved;
+use Statamic\Events\NavTreeSaving;
 use Statamic\Facades\Blink;
 use Statamic\Facades\Nav;
 use Statamic\Facades\Site;
@@ -43,6 +44,11 @@ protected function dispatchSavedEvent()
         NavTreeSaved::dispatch($this);
     }
 
+    protected function dispatchSavingEvent()
+    {
+        return NavTreeSaving::dispatch($this);
+    }
+
     protected function dispatchDeletedEvent()
     {
         NavTreeDeleted::dispatch($this);
diff --git a/src/Structures/Tree.php b/src/Structures/Tree.php
index af7214fd90..1caff9d5d4 100644
--- a/src/Structures/Tree.php
+++ b/src/Structures/Tree.php
@@ -156,6 +156,10 @@ public function findByEntry($id)
 
     public function save()
     {
+        if ($this->dispatchSavingEvent() === false) {
+            return false;
+        }
+
         $this->cachedFlattenedPages = null;
 
         Blink::forget('collection-structure-flattened-pages-collection*');
@@ -166,6 +170,8 @@ public function save()
         $this->dispatchSavedEvent();
 
         $this->syncOriginal();
+
+        return true;
     }
 
     public function delete()
@@ -186,6 +192,11 @@ protected function dispatchSavedEvent()
         //
     }
 
+    protected function dispatchSavingEvent()
+    {
+        //
+    }
+
     protected function dispatchDeletedEvent()
     {
         //
diff --git a/tests/Data/Structures/CollectionTreeTest.php b/tests/Data/Structures/CollectionTreeTest.php
index d591862e99..e5c848e0a1 100644
--- a/tests/Data/Structures/CollectionTreeTest.php
+++ b/tests/Data/Structures/CollectionTreeTest.php
@@ -2,7 +2,9 @@
 
 namespace Tests\Data\Structures;
 
+use Illuminate\Support\Facades\Event;
 use PHPUnit\Framework\Attributes\Test;
+use Statamic\Events\CollectionTreeSaving;
 use Statamic\Facades\Blink;
 use Statamic\Facades\Collection;
 use Statamic\Structures\CollectionTree;
@@ -16,16 +18,6 @@ class CollectionTreeTest extends TestCase
     use PreventSavingStacheItemsToDisk;
     use UnlinksPaths;
 
-    private $directory;
-
-    public function setUp(): void
-    {
-        parent::setUp();
-
-        $stache = $this->app->make('stache');
-        $stache->store('collection-trees')->directory($this->directory = '/path/to/structures/collections');
-    }
-
     #[Test]
     public function it_can_get_and_set_the_handle()
     {
@@ -61,7 +53,7 @@ public function it_gets_the_path()
         $collection = Collection::make('pages')->structureContents(['root' => true]);
         Collection::shouldReceive('findByHandle')->with('pages')->andReturn($collection);
         $tree = $collection->structure()->makeTree('en');
-        $this->assertEquals('/path/to/structures/collections/pages.yaml', $tree->path());
+        $this->assertEquals($this->fakeStacheDirectory.'/content/structures/collections/pages.yaml', $tree->path());
     }
 
     #[Test]
@@ -75,7 +67,7 @@ public function it_gets_the_path_when_using_multisite()
         $collection = Collection::make('pages')->structureContents(['root' => true]);
         Collection::shouldReceive('findByHandle')->with('pages')->andReturn($collection);
         $tree = $collection->structure()->makeTree('en');
-        $this->assertEquals('/path/to/structures/collections/en/pages.yaml', $tree->path());
+        $this->assertEquals($this->fakeStacheDirectory.'/content/structures/collections/en/pages.yaml', $tree->path());
     }
 
     #[Test]
@@ -118,4 +110,36 @@ public function it_does_a_diff()
         $this->assertEquals(['1.1', '2.2', '2.3'], $diff->moved());
         $this->assertEquals(['1.1'], $diff->ancestryChanged());
     }
+
+    #[Test]
+    public function it_fires_a_saving_event()
+    {
+        Event::fake();
+
+        $collection = Collection::make('test')->structureContents(['root' => true]);
+        Collection::shouldReceive('findByHandle')->with('test')->andReturn($collection);
+
+        $tree = $collection->structure()->makeTree('en');
+        $tree->save();
+
+        Event::assertDispatched(CollectionTreeSaving::class);
+
+        $this->assertFileExists($tree->path());
+    }
+
+    #[Test]
+    public function returning_false_in_collection_tree_saving_stops_saving()
+    {
+        Event::listen(CollectionTreeSaving::class, function (CollectionTreeSaving $event) {
+            return false;
+        });
+
+        $collection = Collection::make('test')->structureContents(['root' => true]);
+        Collection::shouldReceive('findByHandle')->with('test')->andReturn($collection);
+
+        $tree = $collection->structure()->makeTree('en');
+        $tree->save();
+
+        $this->assertFileDoesNotExist($tree->path());
+    }
 }
diff --git a/tests/Data/Structures/NavTreeTest.php b/tests/Data/Structures/NavTreeTest.php
index 88d9e93972..7122e3ab50 100644
--- a/tests/Data/Structures/NavTreeTest.php
+++ b/tests/Data/Structures/NavTreeTest.php
@@ -3,7 +3,9 @@
 namespace Tests\Data\Structures;
 
 use Facades\Statamic\Structures\BranchIds;
+use Illuminate\Support\Facades\Event;
 use PHPUnit\Framework\Attributes\Test;
+use Statamic\Events\NavTreeSaving;
 use Statamic\Facades\Blink;
 use Statamic\Facades\File;
 use Statamic\Facades\Nav;
@@ -113,4 +115,28 @@ public function it_doesnt_save_tree_when_ensuring_ids_if_nothing_changed()
         $this->assertEquals($existingTree, $tree->tree());
         $this->assertEquals($existingFileContents, File::get($tree->path()));
     }
+
+    #[Test]
+    public function it_fires_a_saving_event()
+    {
+        Event::fake();
+
+        $nav = tap(Nav::make('links'))->save();
+        tap($nav->makeTree('en', [['id' => 'the-id', 'title' => 'Branch']]))->save();
+
+        Event::assertDispatched(NavTreeSaving::class);
+    }
+
+    #[Test]
+    public function returning_false_in_nav_tree_saving_stops_saving()
+    {
+        Event::listen(NavTreeSaving::class, function (NavTreeSaving $event) {
+            return false;
+        });
+
+        $nav = tap(Nav::make('links'))->save();
+        $tree = tap($nav->makeTree('en', [['id' => 'the-id', 'title' => 'Branch']]))->save();
+
+        $this->assertFileDoesNotExist($tree->path());
+    }
 }