Auto-hide the menu bar on an external monitor

macOS puts a menu bar at the top of every display, so plugging in a monitor gives you a second one you may not want cutting across your reference material or video. Auto-hiding the menu bar applies to all displays at once, so the bar drops out of the way on your external screen and slides back only when you push the pointer up. Set System Settings → Control Center → Automatically hide and show the menu bar → Always.

Auto-hide covers every display

1. Open System Settings → Control Center.
2. Scroll to Automatically hide and show the menu bar and choose Always.

The setting is system-wide — there's no per-display switch for it — so it hides the bar on the built-in screen and the external monitor together. On whichever display holds your pointer, moving to that screen's top edge reveals its menu bar; move away and it hides again. This is consistent on macOS 13 Ventura, 14 Sonoma, and 15 Sequoia. The Terminal equivalent:

# Auto-hide the menu bar on all displays
defaults write NSGlobalDomain _HIHideMenuBar -bool true

# Show it again everywhere
defaults write NSGlobalDomain _HIHideMenuBar -bool false

The preference takes full effect after logging out and back in, so use the Control Center toggle for an instant change.

Which screen even shows the bar?

Whether the external monitor shows its own menu bar depends on a separate display setting:

• Displays have Separate Spaces on (the default): each display is independent and gets its own full menu bar. Auto-hide then keeps both out of sight. Find it in System Settings → Desktop & Dock.
• Displays have Separate Spaces off: the displays join into one Space and only the main display carries the menu bar. Turning this off is another way to keep the bar off a secondary monitor entirely — at the cost of full-screen apps no longer being independent per display. Changing it requires logging out and back in.
• Which display is "main" is set by dragging the small white bar between the display arrangement thumbnails in Displays. The main display is where the menu bar lives when Spaces aren't separate.

So you have two levers: auto-hide (hides the bar on all screens, reversibly) and Separate Spaces (decides whether the secondary screen has a bar at all). For most people who just want the external monitor clean but still usable, auto-hide is the lighter-touch choice.

Tidy the Dock across displays too

The Dock also follows your pointer between screens and can clutter a second monitor. See how to auto-hide the Dock on an external monitor to keep the bottom edge as clean as the top.