diff --git a/core/config/project_settings.cpp b/core/config/project_settings.cpp
index 70e8133eaa9..9b28ef7b810 100644
--- a/core/config/project_settings.cpp
+++ b/core/config/project_settings.cpp
@@ -597,6 +597,7 @@ Error ProjectSettings::_load_settings_text(const String &p_path) {
 			// If we're loading a project.godot from source code, we can operate some
 			// ProjectSettings conversions if need be.
 			_convert_to_last_version(config_version);
+			last_save_time = FileAccess::get_modified_time(get_resource_path().plus_file("project.godot"));
 			return OK;
 		} else if (err != OK) {
 			ERR_PRINT("Error parsing " + p_path + " at line " + itos(lines) + ": " + error_text + " File might be corrupted.");
@@ -676,7 +677,11 @@ void ProjectSettings::clear(const String &p_name) {
 }
 
 Error ProjectSettings::save() {
-	return save_custom(get_resource_path().plus_file("project.godot"));
+	Error error = save_custom(get_resource_path().plus_file("project.godot"));
+	if (error == OK) {
+		last_save_time = FileAccess::get_modified_time(get_resource_path().plus_file("project.godot"));
+	}
+	return error;
 }
 
 Error ProjectSettings::_save_settings_binary(const String &p_file, const Map<String, List<String>> &props, const CustomMap &p_custom, const String &p_custom_features) {
diff --git a/core/config/project_settings.h b/core/config/project_settings.h
index 59c56c23c25..645506f302a 100644
--- a/core/config/project_settings.h
+++ b/core/config/project_settings.h
@@ -78,6 +78,8 @@ protected:
 
 	int last_order = NO_BUILTIN_ORDER_BASE;
 	int last_builtin_order = 0;
+	uint64_t last_save_time = 0;
+
 	Map<StringName, VariantContainer> props;
 	String resource_path;
 	Map<StringName, PropertyInfo> custom_prop_info;
@@ -113,7 +115,6 @@ protected:
 
 	Error _setup(const String &p_path, const String &p_main_pack, bool p_upwards = false);
 
-protected:
 	static void _bind_methods();
 
 public:
@@ -150,6 +151,7 @@ public:
 	Error save();
 	void set_custom_property_info(const String &p_prop, const PropertyInfo &p_info);
 	const Map<StringName, PropertyInfo> &get_custom_property_info() const;
+	uint64_t get_last_saved_time() { return last_save_time; }
 
 	Vector<String> get_optimizer_presets() const;
 
diff --git a/editor/editor_data.cpp b/editor/editor_data.cpp
index 336bf266078..18364dc32f8 100644
--- a/editor/editor_data.cpp
+++ b/editor/editor_data.cpp
@@ -500,6 +500,7 @@ int EditorData::add_edited_scene(int p_at_pos) {
 	EditedScene es;
 	es.root = nullptr;
 	es.path = String();
+	es.file_modified_time = 0;
 	es.history_current = -1;
 	es.version = 0;
 	es.live_edit_root = NodePath(String("/root"));
@@ -656,6 +657,10 @@ void EditorData::set_edited_scene_root(Node *p_root) {
 			p_root->set_filename(edited_scene[current_edited_scene].path);
 		}
 	}
+
+	if (edited_scene[current_edited_scene].path != "") {
+		edited_scene.write[current_edited_scene].file_modified_time = FileAccess::get_modified_time(edited_scene[current_edited_scene].path);
+	}
 }
 
 int EditorData::get_edited_scene_count() const {
@@ -687,6 +692,21 @@ uint64_t EditorData::get_scene_version(int p_idx) const {
 	return edited_scene[p_idx].version;
 }
 
+void EditorData::set_scene_modified_time(int p_idx, uint64_t p_time) {
+	if (p_idx == -1) {
+		p_idx = current_edited_scene;
+	}
+
+	ERR_FAIL_INDEX(p_idx, edited_scene.size());
+
+	edited_scene.write[p_idx].file_modified_time = p_time;
+}
+
+uint64_t EditorData::get_scene_modified_time(int p_idx) const {
+	ERR_FAIL_INDEX_V(p_idx, edited_scene.size(), 0);
+	return edited_scene[p_idx].file_modified_time;
+}
+
 String EditorData::get_scene_type(int p_idx) const {
 	ERR_FAIL_INDEX_V(p_idx, edited_scene.size(), String());
 	if (!edited_scene[p_idx].root) {
diff --git a/editor/editor_data.h b/editor/editor_data.h
index f14a3fb4e02..18b41371628 100644
--- a/editor/editor_data.h
+++ b/editor/editor_data.h
@@ -111,6 +111,7 @@ public:
 	struct EditedScene {
 		Node *root = nullptr;
 		String path;
+		uint64_t file_modified_time = 0;
 		Dictionary editor_states;
 		List<Node *> selection;
 		Vector<EditorHistory::History> history_stored;
@@ -190,6 +191,8 @@ public:
 	Ref<Script> get_scene_root_script(int p_idx) const;
 	void set_edited_scene_version(uint64_t version, int p_scene_idx = -1);
 	uint64_t get_scene_version(int p_idx) const;
+	void set_scene_modified_time(int p_idx, uint64_t p_time);
+	uint64_t get_scene_modified_time(int p_idx) const;
 	void clear_edited_scenes();
 	void set_edited_scene_live_edit_root(const NodePath &p_root);
 	NodePath get_edited_scene_live_edit_root();
diff --git a/editor/editor_node.cpp b/editor/editor_node.cpp
index 12d0d1db08e..8b123bf4086 100644
--- a/editor/editor_node.cpp
+++ b/editor/editor_node.cpp
@@ -594,6 +594,7 @@ void EditorNode::_notification(int p_what) {
 			OS::get_singleton()->set_low_processor_usage_mode_sleep_usec(int(EDITOR_GET("interface/editor/low_processor_mode_sleep_usec")));
 
 			EditorFileSystem::get_singleton()->scan_changes();
+			_scan_external_changes();
 		} break;
 
 		case NOTIFICATION_APPLICATION_FOCUS_OUT: {
@@ -886,6 +887,81 @@ void EditorNode::_sources_changed(bool p_exist) {
 	}
 }
 
+void EditorNode::_scan_external_changes() {
+	disk_changed_list->clear();
+	TreeItem *r = disk_changed_list->create_item();
+	disk_changed_list->set_hide_root(true);
+	bool need_reload = false;
+
+	// Check if any edited scene has changed.
+
+	for (int i = 0; i < editor_data.get_edited_scene_count(); i++) {
+		if (editor_data.get_scene_path(i) == "") {
+			continue;
+		}
+
+		uint64_t last_date = editor_data.get_scene_modified_time(i);
+		uint64_t date = FileAccess::get_modified_time(editor_data.get_scene_path(i));
+
+		if (date > last_date) {
+			TreeItem *ti = disk_changed_list->create_item(r);
+			ti->set_text(0, editor_data.get_scene_path(i).get_file());
+			need_reload = true;
+		}
+	}
+
+	String project_settings_path = ProjectSettings::get_singleton()->get_resource_path().plus_file("project.godot");
+	if (FileAccess::get_modified_time(project_settings_path) > ProjectSettings::get_singleton()->get_last_saved_time()) {
+		TreeItem *ti = disk_changed_list->create_item(r);
+		ti->set_text(0, "project.godot");
+		need_reload = true;
+	}
+
+	if (need_reload) {
+		disk_changed->call_deferred("popup_centered_ratio", 0.5);
+	}
+}
+
+void EditorNode::_resave_scenes(String p_str) {
+	save_all_scenes();
+	ProjectSettings::get_singleton()->save();
+	disk_changed->hide();
+}
+
+void EditorNode::_reload_modified_scenes() {
+	int current_idx = editor_data.get_edited_scene();
+
+	for (int i = 0; i < editor_data.get_edited_scene_count(); i++) {
+		if (editor_data.get_scene_path(i) == "") {
+			continue;
+		}
+
+		uint64_t last_date = editor_data.get_scene_modified_time(i);
+		uint64_t date = FileAccess::get_modified_time(editor_data.get_scene_path(i));
+
+		if (date > last_date) {
+			String filename = editor_data.get_scene_path(i);
+			editor_data.set_edited_scene(i);
+			_remove_edited_scene(false);
+
+			Error err = load_scene(filename, false, false, true, false, true);
+			if (err != OK) {
+				ERR_PRINT(vformat("Failed to load scene: %s", filename));
+			}
+			editor_data.move_edited_scene_to_index(i);
+		}
+	}
+
+	get_undo_redo()->clear_history(false);
+	set_current_scene(current_idx);
+	_update_scene_tabs();
+	disk_changed->hide();
+}
+
+void EditorNode::_reload_project_settings() {
+	ProjectSettings::get_singleton()->setup(ProjectSettings::get_singleton()->get_resource_path(), String(), true);
+}
+
 void EditorNode::_vp_resized() {
 }
 
@@ -1511,6 +1587,7 @@ void EditorNode::_save_scene(String p_file, int idx) {
 		} else {
 			editor_data.set_edited_scene_version(0, idx);
 		}
+		editor_data.set_scene_modified_time(idx, FileAccess::get_modified_time(p_file));
 
 		editor_folding.save_scene_folding(scene, p_file);
 
@@ -3326,7 +3403,7 @@ int EditorNode::new_scene() {
 	return idx;
 }
 
-Error EditorNode::load_scene(const String &p_scene, bool p_ignore_broken_deps, bool p_set_inherited, bool p_clear_errors, bool p_force_open_imported) {
+Error EditorNode::load_scene(const String &p_scene, bool p_ignore_broken_deps, bool p_set_inherited, bool p_clear_errors, bool p_force_open_imported, bool p_silent_change_tab) {
 	if (!is_inside_tree()) {
 		defer_load_scene = p_scene;
 		return OK;
@@ -3366,8 +3443,10 @@ Error EditorNode::load_scene(const String &p_scene, bool p_ignore_broken_deps, b
 
 	if (!editor_data.get_edited_scene_root() && editor_data.get_edited_scene_count() == 2) {
 		_remove_edited_scene();
-	} else {
+	} else if (!p_silent_change_tab) {
 		_scene_tab_changed(idx);
+	} else {
+		set_current_scene(idx);
 	}
 
 	dependency_errors.clear();
@@ -6601,6 +6680,30 @@ EditorNode::EditorNode() {
 	//plugin stuff
 
 	add_editor_plugin(memnew(DebuggerEditorPlugin(this, debug_menu)));
+
+	disk_changed = memnew(ConfirmationDialog);
+	{
+		VBoxContainer *vbc = memnew(VBoxContainer);
+		disk_changed->add_child(vbc);
+
+		Label *dl = memnew(Label);
+		dl->set_text(TTR("The following files are newer on disk.\nWhat action should be taken?"));
+		vbc->add_child(dl);
+
+		disk_changed_list = memnew(Tree);
+		vbc->add_child(disk_changed_list);
+		disk_changed_list->set_v_size_flags(Control::SIZE_EXPAND_FILL);
+
+		disk_changed->connect("confirmed", callable_mp(this, &EditorNode::_reload_modified_scenes));
+		disk_changed->connect("confirmed", callable_mp(this, &EditorNode::_reload_project_settings));
+		disk_changed->get_ok_button()->set_text(TTR("Reload"));
+
+		disk_changed->add_button(TTR("Resave"), !DisplayServer::get_singleton()->get_swap_cancel_ok(), "resave");
+		disk_changed->connect("custom_action", callable_mp(this, &EditorNode::_resave_scenes));
+	}
+
+	gui_base->add_child(disk_changed);
+
 	add_editor_plugin(memnew(AnimationPlayerEditorPlugin(this)));
 	add_editor_plugin(memnew(CanvasItemEditorPlugin(this)));
 	add_editor_plugin(memnew(Node3DEditorPlugin(this)));
diff --git a/editor/editor_node.h b/editor/editor_node.h
index 356ac0caac5..3785d29c41d 100644
--- a/editor/editor_node.h
+++ b/editor/editor_node.h
@@ -422,6 +422,9 @@ private:
 	Label *version_label;
 	Button *bottom_panel_raise;
 
+	Tree *disk_changed_list;
+	ConfirmationDialog *disk_changed;
+
 	void _bottom_panel_raise_toggled(bool);
 
 	EditorInterface *editor_interface;
@@ -641,6 +644,10 @@ private:
 	static void _resource_loaded(RES p_resource, const String &p_path);
 
 	void _resources_changed(const Vector<String> &p_resources);
+	void _scan_external_changes();
+	void _reload_modified_scenes();
+	void _reload_project_settings();
+	void _resave_scenes(String p_str);
 
 	void _feature_profile_changed();
 	bool _is_class_editor_disabled_by_feature_profile(const StringName &p_class);
@@ -741,7 +748,7 @@ public:
 	void fix_dependencies(const String &p_for_file);
 	void clear_scene() { _cleanup_scene(); }
 	int new_scene();
-	Error load_scene(const String &p_scene, bool p_ignore_broken_deps = false, bool p_set_inherited = false, bool p_clear_errors = true, bool p_force_open_imported = false);
+	Error load_scene(const String &p_scene, bool p_ignore_broken_deps = false, bool p_set_inherited = false, bool p_clear_errors = true, bool p_force_open_imported = false, bool p_silent_change_tab = false);
 	Error load_resource(const String &p_resource, bool p_ignore_broken_deps = false);
 
 	bool is_scene_open(const String &p_path);