diff --git a/dodo/app.py b/dodo/app.py
index e01369d..f47c472 100644
--- a/dodo/app.py
+++ b/dodo/app.py
@@ -24,6 +24,7 @@
 import os
 import signal
 import fcntl
+import platform
 import subprocess
 from typing import Optional, Literal
 import logging
@@ -165,6 +166,8 @@ def _handle_signal_wakeup(self) -> None:
         self._cleanup_sync()
         self.quit()
 
+        self.update_dock_badge()
+
     def show_help(self) -> None:
         """Show help window"""
 
@@ -363,6 +366,8 @@ def refresh_panels(self) -> None:
         w = self.tabs.currentWidget()
         if w and isinstance(w, panel.Panel): w.refresh()
 
+        self.update_dock_badge()
+
     def update_single_thread(self, thread_id: str, msg_id: str|None=None):
         current = self.tabs.currentWidget()
         for i in range(self.num_panels()):
@@ -372,6 +377,34 @@ def update_single_thread(self, thread_id: str, msg_id: str|None=None):
                 if w == current and w.dirty:
                     w.refresh()
 
+        self.update_dock_badge()
+
+    def update_dock_badge(self) -> None:
+        """Update the macOS dock icon badge with the unread count
+
+        Uses the query in :func:`~dodo.settings.macos_dock_badge_query` to count
+        unread threads and display the count as a native dock badge.
+        Requires ``pyobjc-framework-Cocoa`` on macOS; silently does nothing
+        on other platforms or if pyobjc is not installed."""
+
+        if platform.system() != 'Darwin' or not settings.macos_dock_badge_query:
+            return
+
+        try:
+            from AppKit import NSApp  # type: ignore[import-untyped]
+        except ImportError:
+            return
+
+        try:
+            r = subprocess.run(
+                ['notmuch', 'count', '--output=threads', '--', *settings.macos_dock_badge_query.split()],
+                stdout=subprocess.PIPE, timeout=5)
+            count = int(r.stdout.decode('utf-8').strip())
+            label = str(count) if count > 0 else ''
+            NSApp.dockTile().setBadgeLabel_(label)
+        except Exception:
+            pass
+
     def _cleanup_sync(self) -> None:
         """Stop the sync timer and terminate any running sync thread"""
         if self.sync_timer is not None:
diff --git a/dodo/settings.py b/dodo/settings.py
index c112eb2..df31ed6 100644
--- a/dodo/settings.py
+++ b/dodo/settings.py
@@ -173,6 +173,15 @@
 tag:trash"` and use `query:inbox` as a search term.
 """
 
+macos_dock_badge_query = 'tag:unread AND tag:inbox'
+"""Notmuch query whose thread count is shown as the macOS dock badge
+
+Set this to a notmuch search query. The number of matching threads will be
+displayed as a badge on the dock icon. Set to an empty string to disable.
+
+Requires the ``pyobjc-framework-Cocoa`` package on macOS.
+"""
+
 no_hooks_on_send = True
 """disable/enable calling notmuch hooks when sending email
 
diff --git a/setup.py b/setup.py
index 45cf93e..60160bf 100644
--- a/setup.py
+++ b/setup.py
@@ -33,7 +33,12 @@
     packages=["dodo"],
     package_data={'': ['*.svg']},
     data_files=data_files,
-    install_requires=["PyQt6>=6.2", "PyQt6-WebEngine>=6.2", "bleach>=5.0"],
+    install_requires=[
+        "PyQt6>=6.2",
+        "PyQt6-WebEngine>=6.2",
+        "bleach>=5.0",
+        "pyobjc-framework-Cocoa; sys_platform == 'darwin'",
+    ],
     python_requires=">=3.7",
     entry_points={'console_scripts': 'dodo=dodo.app:main'},
 )