Kaley Cuoco -- Save a Horse ... Ride a Jedi

Kaley Cuoco just drained the asthma inhalers of science fiction geeks across the galaxy ... by dressing up as a sexy Luke Skywalker.

The "Big Bang Theory" star was at the Longines Masters of Los Angeles -- a horse jumping event -- where she brought a whole Star Wars team to a charity costume part of the program, and even had a lightsaber duel with Darth Vader.

As we previously reported ... Cuoco added a new horse to her stable after it was revealed she filed for divorce from Ryan Sweeting.