01. Mahershala Ali
Real Name: Mahershalalhashbaz Gilmore
Oscar-winning actor Mahershala Ali‘s pastor mother picked his name out of the Bible, according to the Guardian. He changed his last name from Gilmore to Ali when he converted from Christianity to Islam in 2000, and several years later shortened his first name in the hopes that it would advance his career.
02. Bruno Mars
Real Name: Peter Gene Herandez
“[The stage name] Bruno is after Bruno Sammartino, who was this big, fat wrestler,” Bruno Mars, born Peter Gene Herandez, told the Associated Press. “I was this chunky little baby, so my dad used to call me that as a nickname.” And his surname? “‘Mars came up because a lot of girls say I’m out of this world!”
03. Emma Stone
Real Name: Emily Stone
“My real name is Emily Stone, but when I started acting, that name was already taken by another actress, so I had to come up with a different one,” Emma Stone explained to W Magazine about her moniker. Originally she opted for Riley, but after hearing the name out loud on the set of Malcolm in the Middle, she realized that it didn’t fit her at all.
04. Larry King
Real Name: Lawrence Zeiger
Lawrence Zeiger became Larry King while working at a small radio station in Miami Beach. While there, the general manager of the station told him that his last name was too ethnic, and so minutes before going on air, he chose the surname King, borrowing it from an advertisement in the paper for King’s Wholesale Liquor.
05. Katy Perry
Real Name: Katheryn Hudson
Katheryn Hudson adopted the moniker Katy Perry because she didn’t want to be confused with Kate Hudson. Perry is her mother’s maiden name.
06. Tom Cruise
Real Name: Thomas Mapother IV
Born Thomas Mapother IV, this action star was happy to shed his estranged father’s last name and instead use his middle name when he rechristened himself Tom Cruise. For this reason, you may not have realized that he’s related to Lost actor William Mapother—his first cousin.
Real Name: Robyn Rihanna Fenty
Though born Robyn Fenty, this soulful singer goes by her middle name, Rihanna. However, if you’re a fan of the Barbadian-born beauty, then you probably already knew her last name, given that it’s also the name of her cosmetics and lingerie lines.
08. Snoop Dogg
Real Name: Calvin Broadus Jr.
As you might have already guessed, Snoop Dogg isn’t the rapper’s real name. Born Calvin Broadus, Jr., his “Snoop Dogg” nickname stems from the fact that as a child, his mother used to say that he looked like Snoopy, Charlie Brown’s canine sidekick. “I used to love Peanuts and Charlie Brown—Snoopy was my favorite cartoon character growing up,” Snoop told Esquire. “I watched so much, I started to look like him.”
09. Vin Diesel
Real Name: Mark Sinclair
That’s right, pick your jaw off the floor: Vin Diesel is not the name on the action star’s birth certificate. He was first given the much more traditional name of Mark Sinclair. While the actor hasn’t confirmed the origin of his stage name, it supposedly stems from Vincent—the last name the family took on when his mother remarried—and his own energetic personality. Another Hollywood legend is that he had to change his name to protect himself when he worked as a bouncer, pre-stardom.
10. Kit Harrington
Real Name: Christopher Catesby Harington
The Game of Thrones star’s real name is Christopher Catesby Harington, but he didn’t know his name wasn’t Kit Harrington until he was 11 years old. He told Glamour: “Kit is traditionally an offshoot of Christopher, it’s just not used that often. My middle name is Catesby.” For more pairs like Harrington and Rose Leslie, check out 15 Onscreen Couples You Totally Forgot Dated in Real Life.