For example, although few of us outside Tinsel town know the names Dianne Belmont, Melvin Kaminski, and Jerome Silverman, many of us know the Hollywood names of those three comedian-actors: Lucille Ball, Mel Brooks and Gene Wilder.

There are plenty of reasons why an aspiring actor might change his or her name. Stewart Granger changed his name from Jimmy Stewart because that name was already taken. William Henry Pratt changed his name to the scarier-sounding Boris Karl off before he took on the role of Frankenstein. And Eddie Albert Heimberger dropped his last name after he realized that he was becoming known as Eddie Hamburger.
Of course, not everyone has to change their name in order to make it in Hollywood. Consider this roster of stars that rose to fame under their real names: Spencer Tracy, Katherine Hepburn, Jimmy Stewart (the one who kept his name), Humphrey Bogart, and, most famously of all, Ronald Reagan.