What's in a name? A lot, according to these stars.

After all, a unique moniker sticks in the mind better than a catchy jingle. Take Miley Cyrus, who was born Destiny Hope Cyrus but adopted a stage name based on her childhood nickname "Smiley" when she started acting in Hannah Montana. Fast forward to 2008, the singer legally changed her full name to Miley Ray Cyrus, with her new middle name serving as a nod to both her dad Billy Ray Cyrus and grandfather Ronald Ray Cyrus.

"A lot of people say Miley changed her name to Miley Ray because of Billy Ray, but that's not true," Billy Ray told CNN in 2009. "She did that in honor of my dad, because the two of them just loved each other to pieces."

In other cases, celebs simply changed their names to avoid confusion. For instance, Jason Sudeikis' mom started calling him by his middle name instead since both he and his dad share the first name Daniel, while Emma Stone had to register in the Screen Actors Guild with a moniker different from her birthname because there was already an Emily Stone in the system.

"For a 16-year-old, picking a new name is an interesting prospect, and back then I said, ‘I'm now going to be Riley Stone!'" Emma recalled in a 2017 interview with W Magazine. "So, for about six months I was called Riley. I landed a guest spot on Malcolm in the Middle, and one day they were calling, ‘Riley! Riley! Riley! We need you on set, Riley!' and I had no idea who they were talking to."

The Oscar winner eventually landed on the name Emma, but admittedly still "miss Emily" from time to time.

She added, "I would love to get her back."

From Meghan Markle to Tom Cruise, keep reading for more stars who changed their name before finding fame.

Cardi B took on the name Bacardi after family and friends started calling her sister Hennessy. Later on she shortened the name to something that suited her quite a bit more.

Before she became the Duchess of Sussex, Meghan Markle was briefly known as Rachel. 

Shania Twain shared the origin story of her stage name during an appearance on Apple Music's Home Now Radio: "In short, I was born, Eilleen Regina Edwards, and then I was adopted and I became Eilleen Regina Twain. Then I became a professional singer and I needed a stage name that sounded a little less like my grandmother's name, because I'm named after my grandmother, both my grandmothers, Eilleen and Regina. I think, in my mind, I was just not really wanting to be called my grandmother's name onstage, so I decided to change it to Shania Twain. I met somebody with the name Shania, thought it was beautiful, and Shania Twain was born."

Oddly enough, Gigi Hadid got her stage name in school when the teacher would confuse her and a girl named Helena. Since her mom called her "gigi" as a term of endearment at home, she told the teacher to just call her Gigi and it simply stuck. 

If you're looking for an explosive action-star name, how about Vin Diesel instead?

Miley Cyrus' bright smile is what inspired her childhood nickname, Smiley. Eventually the name was shortened to Miley and it stuck. 

Apparently the singer looked more like a Bruno than a Peter, so one day his dad started calling him Bruno. Ever since, he has been known as Bruno Mars.

Before the meat dresses and chart-topping music, Lady Gaga was just an everyday girl from New York.

Jason Sudeikis confirmed on Today that he was named Daniel after his father, but following some confusion, his mom started using his middle name Jason to avoid confusion. 

Emma Stone ended adopting this stage name after finding out that the Screen Actors Guild already had a member registered under her birthname. 

Turns out Reese isn't even Reese Witherspoon's middle name. The actress chose the moniker in honor of her mother, whose maiden name is Reese.

Every artist has an alter ego, and Lana Del Rey just happens to be the persona of choice for the singer. 

In 2014, Frank Ocean legally changed his name because, why not? 

A little known fact about 30 Rock's Tina Fey is that she is actually named Elizabeth. The comedian made a not so subtle tribute to her birth name by naming her character Liz Lemon.

This pioneer of West Coast rap would later go on to be known as Snoop Dogg.

Turns out the "Royals" singer is really into learning about the aristocracy, hence the reason why she chose the name Lorde, but with a feminine 'e.'

Before he started shaking his bonbon for the masses, music superstar Ricky Martin went by this everyday name.

It's hard to believe that Iggy Azalea was born Amethyst Kelly!

Fans were confused when Taylor Swift thanked then-boyfriend Adam in an acceptance speech, which lead people to the discovery that Calvin Harris is simply a stage name. The DJ told Shortlist magazine he chose the name because his first single was more soulful and wanted something a bit more "racially ambiguous."

Before she became a household name, this was what erstwhile Friend Jennifer Aniston answered to.

Alicia Keys didn't always have such a musical name.

Before he became arguably the biggest movie star in the world, Tom Cruise went by this name.

Back when she was born in 1980, this was how the future bigtime actress Natalie Portman greeted the world.

Before she became a big-time TV star and married Ellen DeGeneres, this was the name Portia de Rossi answered to.

Guess music superstar Elton John didn't think his original name would be a hit with audiences.

Check former Paris Hilton BFF Nicole Richie's birth certificate and this is the name you'll see.

All it took was a nickname from some high school friends, and U2 frontman Bono's famous moniker was born.

We agree. Carmen Electra is much more effective when it comes to selling a sexy Baywatch persona.

True, Jamie Foxx just seems more fitting for an Oscar-winning Hollywood party guy.

Before she'd starred in dozens of huge Hollywood movies and married two Tinseltown A-listers, this was the name Demi Moore went by.