We guarantee you've heard of the stars on the following list.
But did you know about their siblings? Did you know that these brothers and sisters are out there and actually exist for real?
It's true! Scroll down to see what we mean...
Mandi and Ryan Gosling
Ryan and his older sister, Mandi were quite the double act when they performed together at weddings and in talent shows.
Patricia and Gisele Bündchen
Like Gisele, Patricia was a model. After her career fizzled out, she became Gisele's manager.
Michael B. and Jamilla Jordan
Michael's older sister, Jamilla is a producer on Ink Master. The brother and sister are very close to one another. Michael has even claimed that living with his sister shaped him as the person he is today.
Tom and Emma Hiddleston
Like Tom, Emma is an actress, who has an active IMDB profile. Maybe acting is part of the family genes.
Dylan and Zac Efron
While Zac Efron is busy in the acting game, Dylan is sticking to the world of poetry.
Hunter and Scarlett Johansson
Hunter started off in acting, but these days, he's dabbling more in the political world.
Laura and Sarah Silverman
Laura and Sarah are well-known comedians, with Laura joining her sister on The Sarah Silverman Program, before moving on to become a voice actress.
Liam, Luke and Chris Hemsworth
All three brothers are actors, but Luke has yet to make it big in Hollywood. He is returning to the acting game with the aim of making it in Hollywood.
Hallie and Jesse Eisenberg
Hallie was the face of Pepsi commercials that were popular a few years back. To date, she has been unable to break out of her brother's shadow.
Lee Anne De Vette and Tom Cruise
Lee Anne has been Tom's publicist for most of his career.
Chloe Grace and Trevor Duke Moretz
Trevor was once an actor and coached his sister to stardom. He accompanies her on her various jobs these days.
Felicity and Emily Blunt
Felicity is a literary agent in both the U.K. and the U.S. She also set her sister, Emily, up with Stanly Tucci.
Jack, Ozzy, Kelly, Sharon and Aimee Osbourne
On the far right is the other Osborne daughter, Aimee. She opted to stay away from the reality show to find herself a career as a singer.
Peter and Lupita Nyong'o
Peter attended the Oscars with Lupita and has become something of a sensation on Instagram.
Colin and Claudine Farrell
Colin's sister works as his personal assistant. Talk about keeping it in the family.
Scott and Chris Evans
Like Chris, Scott is an actor, with an impressive IMDB page.
Lana Del Rey and Chuck Grant
Lana's sister is a successful photographer, who has worked with the likes of Marie Claire and New York Magazine.
Dave, James and Tom Franco
Middle brother, Tom, is a sculptor, painter and illustrator, and writer.
Penelope and Monica Cruz
Penelope and Monica started in the world of dancing, before making the move to movies. Fun fact: Monica filled in for Penelope on Pirate of the Carribean: On Stranger Tides.