1.

Michael J. Fox is actually Michael A. Fox — the “A” is for Andrew.

When he registered with SAG, his name was already taken by the character actor Michael Fox, who appeared in Young Frankenstein and The Twilight Zone.

Michael J. Fox didn’t want to be Andrew Fox or Andy Fox, and just using “A” sounded too close to the Canadian “eh” to the Alberta native’s ears. So he chose “J” after actor Michael J. Pollard from Bonnie and Clyde.

2.

Jason Derulo is actually Jason Desrouleaux.

“Derulo” is the phonetic spelling of “Desrouleaux,” so it reads exactly the way it’s supposed to be pronounced.

3.

Meryl Streep is actually Mary Streep.

Naming the firstborn daughter Mary was a tradition in her mother’s family, but her father coined the nickname “Meryl” — which the actor hated.

However, it stuck, and — despite wishing her name was Patty or Cathy — Meryl Streep became a household name.

4.

Meryl’s firstborn daughter and fellow actor Mamie Gummer is actually Mary Gummer, continuing the family tradition.

She’s nicknamed after her great-grandmother, who also went by Mamie.

5.

Nicki Minaj was born Onika Maraj, and friends called her Nicki or Cooky.

When she signed one of her first production deals, someone at the company won a fight with Nicki about changing her last name to “Minaj” — and she’s hated it ever since.

6.

Emma Stone is actually Emily Stone.

Another SAG member was already registered under her name, so she decided to use the name Riley Stone.

However, six months later, she decided to go back and change her name to Emma — the name that she’d wished for as a Baby Spice-obsessed kid.

7.

Prince may sound like a stage name, but all he did was drop his middle and last name. He was born Prince Rogers Nelson.

However, his name was originally his father’s stage name. Jazz musician John Nelson was the Prince Rogers in The Prince Rogers Trio.

From 1993-2000, Prince used a different stage name — the unpronounceable “love symbol” — as an act of rebellion against his record label for refusing to let him release new music as soon as it was ready.

8.

Billie Eilish goes by her first name and one of her middle names. Her full name is Billie Eilish Pirate Baird O’Connell.

However, she was almost Billie Pirate — until her uncle shot it down.

9.

Nina Dobrev is actually Nikolina Dobreva.

She chose to shorten her name at the start of her acting career.

10.

J. Cole is actually Jermaine Cole.

As a teenager, he rapped under the name Therapist, which was suggested by his fellow Bomm Sheltuh members.

However, to him, Therapist felt more like a wrestler’s name than a rapper’s, so he decided to change his name to J. Cole.

11.

Fergie’s stage name is based on her original last name, Ferguson. She was born Stacy Ann Ferguson.

However, in 2013, she made her stage name legal and adopted her then-husband’s last name, making her Fergie Duhamel.

12.

Ashton Kutcher goes by his middle name. His full name is Christopher Ashton Kutcher.

At 19, he decided to change his name when he starting acting.

13.

Halsey is an anagram of Ashley Frangipane’s first name.

They thought Ashley Frangipane was “weak and silly and sad,” so they came up with a new name while riding the New York City subway to the Halsey Street stop in Brooklyn.

“At the time, I felt that Ashley didn’t deserve to be famous and successful because she wasn’t that special, but if I made Halsey, maybe she could be,” she told Cosmopolitan.

14.

Barbra Streisand was born Barbara Streisand.

She dropped the second “a” from Barbara when she was 18 because she wanted to be unique but didn’t want to change her name completely.

15.

And finally, Guy Fieri was born Guy Ferry.

Fieri was actually his family’s original name, but his grandfather changed it when he emigrated from Italy to the US. However, in 1995, Guy changed it back.