Actors Maggie and Jake Gyllenhaal, who both starred in "Donnie Darko" and count movies such as "Secretary," "The Dark Knight" and "Crazy Heart" and "October Sky," "Brokeback Mountain" and "Source Code" on their respective resumes, are seen here walking the red carpet together at the 2010 Oscars.
Ben Affleck directed his little brother Casey in 2007's "Gone Baby Gone."
Brother and sister acting duo John and Joan Cusack have appeared together in movies several times, including 2008's "War, Inc." (pictured).
Emily Deschanel has starred in the Fox drama "Bones" since 2005. Younger sister Zooey, who has starred in movies such as "Elf" and "(500) Days of Summer," joined her on the network with the sitcom "New Girl" in 2011.
Dennis Quaid, known for such movies as "The Big Easy," "Innerspace" and "The Right Stuff," has a brother nearly as famous.
When Randy Quaid earned a Best Supporting Actor Oscar nomination for 1973's "The Last Detail," Dennis dropped out of college to move to Los Angeles and pursue an acting career. The older Quaid's most memorable roles include "Independence Day" and "Kingpin" and as Cousin Eddie in the "National Lampoon's Vacation" movies.
John Belushi, who had memorable roles in "The Blues Brothers" and "Animal House" before dying from a drug overdose at age 33 on March 5, 1982, has a younger brother who also took up acting.
Although not as successful as his brother, James Belushi has carved out an acting career that includes roles in movies such as "About Last Night ..." and "K-9" and his own sitcom in "According to Jim."
Martin Sheen has seen all four of his kids, Emilio, Ramón, Carlos and Renée, get into acting. All of them kept their father's real last name, Estevez, including Emilio Estevez, but Carlos took his father's stage name.
You may better know Sheen's son, born Carlos Irwin Estevez, as the hard-partying and full Tiger-blooded actor Charlie Sheen.
You already know about famous twin sisters Mary-Kate and Ashley Olsen, who built a entertainment and fashion empire after starring on "Full House," but do you know their up-and-coming younger sister?
Mary-Kate and Ashley's younger sister Elizabeth Olsen became an actress as an adult, making an acclaimed film debut in 2011's "Martha Marcy May Marlene" (pictured) and also starring in the 2012 horror movie "Silent House." She also has roles in the upcoming "Godzilla" and "Avengers: Age of Ultron."
The Kardashian sisters -- Kim, Kourtney and Khloe -- have become reality TV stars with their show "Keeping Up with the Kardashians" and its various spin-offs. The show also includes younger sisters Kendall and Kylie Jenner.
James Franco has already conquered acting -- and seemingly just about everything else he tries, besides Oscar hosting -- and his younger brother, Dave Franco, seen here in a scene from "21 Jump Street," is aiming to do the same.
Like Dennis Quaid, Julia Roberts was inspired by the Hollywood success of an older sibling when she decided to give acting a try.
Julia's older brother is Eric Roberts, who earned an Oscar nomination for 1985's "Runaway Train." The two also have another sibling, Lisa Roberts Gillan, who also is an actor, with small parts in movies such as "Runaway Bride," "Raising Helen" and "Eat Pray Love."
Michael Jackson may have been the most famous Jackson, but he had plenty of famous siblings, including sisters LaToya and Janet, seen here with their brother during a lunch break at a pretrial hearing in his molestation case in Santa Maria, Calif., on Aug. 16, 2004.
Moviegoers are already familiar with brothers Luke (center) and Owen Wilson (right), but they also have another brother who both acts and directs. That would be Andrew Wilson, seen here at left with his brothers in 2007.
Alec Baldwin is the most famous and oldest, but he is just one of four acting Baldwin brothers, including Stephen Baldwin, seen here with his older brother. The other Baldwins are Daniel and Billy. The brothers also have two sisters.
Both Beau and Jeff Bridges followed the example set by their father, the late actor Lloyd Bridges.
Warren Beatty, seen here with his wife, actress Annette Bening, at the 2011 Oscars, won a Best Director Oscar for "Red" and has a famous sister with an Oscar of her own.
Shirley MacLaine, Beatty's older sister, won an Oscar for "Terms of Endearment" and has been nominated another five times.
Mark Wahlberg got his start rapping along with his Funky Bunch as "Marky Mark," but the actor has another musical brother who has tried his hand at acting.
Mark's older brother Donnie Wahlberg is a member of 1980s boy band New Kids on the Block and has also had acting roles in movies such as "The Sixth Sense" and TV shows like "Band of Brothers" and "Blue Bloods."
Peter Fonda, seen here with daughter Bridget Fonda, is well known for movies such as "Easy Rider" and "Ulee's Gold," both of which earned him Oscar nominations. His older sister surpassed him, winning two Oscars of her own.
Jane Fonda won Best Actress Oscars for "Klute" and "Coming Home," earning another five nominations over her career so far.
Ashlee Simpson (left) followed older sister Jessica into the music world after starting out as an actress on "7th Heaven."
Mother Naomi Judd has seen both of her two daughters see success, older daughter Wynonna (right) as a country singer and singing partner in the duo The Judds, and Wynonna's younger half-sister, Ashley Judd, as an actress with movies such as "Kiss the Girls," "Double Jeopardy" and "High Crimes" to her credit.
Damon Wayans, known for the TV shows "In Living Color" and "My Wife and Kids" and movies such as "Major Payne" and "The Last Boy Scout," is one of 10 kids in his family, many of whom have also gone into the entertainment industry.
Two of Damon's brothers are Marlon and Shawn Wayans, who have collaborated on movies such as "Scary Movie," "White Chicks" and "Dance Flick." Other Waylans siblings include Keenen Ivory Wayans, Kim Wayans and Nadia Wayans.
By the time she was a teen, Dakota Fanning (left) had established an acting career thanks to roles in the TV miniseries "Taken" and movies like "I Am Sam" and "War of the Worlds." Little sister Elle Fanning (right) is following in her footsteps with roles in movies such as "Super 8" and "We Bought a Zoo."
Kevin Dillon (right) played the older brother of a more famous acting sibling in "Entourage." In real life, he's the younger brother of Oscar-nominated actor Matt Dillon ("Crash").
Actor David Arquette (right) directed his older sister Patricia on an episode of her TV drama "Medium." The brother-sister pair also have three siblings, Rosanna, Alexis and Richmond, who also act.
Ralph Fiennes has earned Oscar nominations for "Schindler's List" and "The English Patient," but his younger brother, Joseph Fiennes, has proved a successful actor himself with roles in "Shakespeare in Love" and the TV show "FlashForward." The two have four siblings, two of whom are film directors and one who is a music composer.
Chris Hemsworth (left) may have scored the higher profile acting gig with the title role in "Thor," but little brother Liam (right) is nipping on his heels with roles in "The Last Song" and "The Hunger Games." The Aussie brothers also have an older brother, Luke, who is an Australian soap opera actor.
Director Ron Howard ("Apollo 13," "Cinderella Man" and "A Beautiful Mind") often finds roles in his movies for his brother, Clint. The younger Howard has also appeared in such movies as "Night at the Museum 2," "How to Eat Fried Worms" and "Fun with Dick and Jane."
She's a "little bit country" and he's a "little bit rock and roll," but siblings Marie and Donny Osmond have been singing together since the 1970s. Donny was also once a member of The Osmonds, a group that included him and his five brothers.
The Jonas Brothers -- (from left to right) Nick, Joe and Kevin -- followed in the tradition of The Osmonds as a band of brothers.
The Williams sisters -- Venus (left) and Serena -- have dominated tennis off and on since the late 1990s.
Peyton Manning got there first, winning Super Bowl XLI in 2007. But it didn't take long for his little brother to catch him and then surpass him.
The following year, Eli Manning led the New York Giants to a championship in Super Bowl XLII, beating the previously unbeaten New England Patriots. He again won a title in February 2012, once again leading the Giants to an upset victory over the highly favored Patriots 21-17 in Super Bowl XLVI.