The Surprising Real Names Of 30 Celebrities

Sometimes you need to change your name to make it as a star in Hollywood or the music business.

When Michael Keaton accepted his best actor Golden Globe for "Birdman," he told the crowd his birth name was actually Michael Douglas.

The 63-year-old actor changed his name early in his career to avoid confusion with the actor of the same name and TV host Mike Douglas. It's believed he chose Keaton because of comedian Buster Keaton.

Plenty of today's biggest stars don't go by their birth names - Reese Witherspoon, Mila Kunis, and Natalie Portman.

However, you probably aren't familiar with how they ended up with their current monikers.