Watching inflight movies on my Mac

According to the Southwest website, the only apps they have for in-flight entertainment are for Android and iOS devices.

No apps for Windows or Mac computers are available from Southwest.

You would have to have wifi network connection to stream movies.

Or, you could connect an external DVD player.

Or, you could preload a movie onto your computer before getting onto the plane.

If you mean stream a movie provided by the airline, you would have to ask the airline.