Rotate MacBook Display Orientation
The same way that you rotate screen orientation on a display connected to a Mac can be done with the built-in display of a MacBook, MacBook Pro, or MacBook Air (pictured).
- Launch System Preferences (quit it if it’s already open)
- Hold down the Command+Option keys and click on “Display”
- Look for ‘Rotation’ on the right side of the Display window and take your pick
After the display has been rotated, the resolutions adjust from width x height to height x width. Here’s a screenshot taken with the display on a MacBook Air set at 90° rotation:
If System Preferences is already open then holding down Command+Option doesn’t seem to make the Rotatation menu appear. If you run into that, just quit out of System Prefs and relaunch it.
Note: This does have some practical use, as you can see in a recent Mac setup post showing a MacBook Pro sideways next to a Cinema Display.