You’ve probably heard of Olivia Wilde, right? But have you heard of Olivia Jane Cockburn, which happens to be the actress’ given name? We all know Stevie Wonder is an icon, but there’s a good chance he might not have had the same level of success had he kept his real name, Stevland Judkins. And these are just two of a long line of celebrities who changed their names.

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It’s not uncommon for actors to adopt stage names—often their real ones are too long, too difficult to pronounce, too ethnic, or simply not sexy enough for the marquis (ahem, the aforementioned Olivia Jane Cockburn.)

Plus, in some cases, certain acting guilds, such as SAG, stipulate that no two members may have identical working names, causing some stars to change their names even if they weren’t planning to (for example, Julia Roberts was born Julie Roberts, but there was another registered actress under that name.)

More: 50 Actors Who Turned Down Iconic Roles

In the interest of “who knew?!” celebrity facts (our favorite kind), we’ve rounded up 50 celebrities’ real names, and for some, explained why they changed them. Others, as you’ll see, are pretty self explanatory.

Click through the gallery above and let us know: Which celebrities’ real name shocked you the most?