By the age of 10, Katherine Heigl was working with Wilhelmina Models posing on the covers of magazines and for Sears and Lord & Taylor catalogs.
A 14-year-old Heigl hit Hollywood in 1992, going on to star in "Grey's Anatomy," "27 Dresses," and "The Ugly Truth."
A 25-year-old Josh Duhamel was named Male Model of the Year at an International Model and Talent Association competition in 1997.
Check out video of Duhamel strutting his stuff here >
Duhamel is now most commonly known for his work as Major Lennox in "Transformers" and roles in TV shows "Las Vegas" and "All My Children."
next slide will load in 15 secondsSkip AdSkip AdAshton Kutcher competed in the IMTA competition, too, taking second place to Duhamel. Kutcher continued modeling with New York's Next agency, landing gigs with Calvin Klein and Abercrombie (pictured below).
Shortly after the big competition, Kutcher was cast as Michael Kelso in "That '70s Show." He is now the highest-paid actor on TV for his role in "Two and a Half Men."
Back in 2006, Jennifer Lawrence was a struggling actress posing for an Abercrombie & Fitch ad.
Now 23, Lawrence has already won an Oscar for her role in last year's "Silver Linings Playbook" and is nominated again this year for "American Hustle." Not to mention she's the star of a little franchise called "Hunger Games."
Before he joined the popular "Twilight" film series, a 19-year-old Kellan Lutz appeared in the below ad for Abercrombie & Fitch.
next slide will load in 15 secondsSkip AdSkip AdLutz, who is still signed with Ford Models, is set to play the lead in this year's "The Legend of Hercules."
Cameron Diaz joined Elite Model Management when she was 16-years-old, picking up gigs with Calvin Klein, Levi's, and this 1990 Seventeen Magazine cover.
Now the highest paid actress over 40, Diaz joins Kate Upton in this year's "The Other Woman" and will play Miss Hannigan in an "Annie" remake.
Before the age of 17, Ian Somerhalder was already in the public spotlight as a young male model, posing for the likes of Versace and Nautica.
Though we had to say goodbye to Somerhalder's character Boone on the hit show "Lost," the former model's good looks are still gracing TV screens on "The Vampire Diaries."
next slide will load in 15 secondsSkip AdSkip AdAt the age of 16, Charlize Theron left her home in South Africa for a modeling career in Milan. After a year modeling throughout Europe, she moved to NYC to study ballet.
An injury cut things short, paving the way for a film career that has since included roles in "The Cider House Rules," "Monster" — for which she won an Oscar for Best Actress — and 2012's "Prometheus."
Uma Thurman began modeling at the age of 15, signing with Click Models and appearing in Glamour magazine and British Vogue.
The Oscar-nominated actress can soon be seen in Lars von Trier's erotic thriller "Nymphomaniac." She has also starred in hits such as "Kill Bill," "Pulp Fiction," and "Batman & Robin."
Mark Wahlberg was just a 21-year-old going by his rap name Marky Mark when he shot this Calvin Klein ad with supermodel Kate Moss in 1992.
Watch one of his commercials here.
next slide will load in 15 secondsSkip AdSkip AdWahlberg is now an Oscar-nominated actor and producer, with hits like "Entourage," "The Fighter," and "Boardwalk Empire" on his resumé.
Emma Roberts was only 14 when she posed for an Abercrombie & Fitch ad in 2005.
Two years later she was playing the title role in "Nancy Drew" and she currently stars on hit TV series "American Horror Story."
As a Ford model, Channing Tatum walked designer runways, appeared in TV commercials and music videos, and posed for ad campaigns like the below for Abercrombie & Fitch.
Not surprisingly, Tatum was named People's "Sexiest Man Alive" in 2012 after starring in "Magic Mike" (based on his life), "White House Down," and he will resume his role as Jenko in this year's "22 Jump Street" sequel.
next slide will load in 15 secondsSkip AdSkip AdAs a young girl in the 1990s, Mischa Barton signed with Ford Models and modeled for well-known brands, including Calvin Klein Jeans.
Barton appeared in both "Notting Hill" and "The Sixth Sense" by the time she was 13, and became most well-known for playing Marissa Cooper on "The O.C."
Olivia Wilde joined the ranks of Abercrombie models-turned-actors with this 2004 ad.
That same year, Wilde was cast as Alex in "The O.C." alongside Mischa Barton. Wilde has since appeared in "House M.D.", "Tron," and this year's "Rush," among many others.
Leighton Meester signed with the Wilhelmina Models as a young girl. She modeled for Ralph Lauren and Limited Too, among other brands.
next slide will load in 15 secondsSkip AdSkip AdMeester began acting at the age of 14, though her starring role came in 2007 as Blair in teen drama series "Gossip Girl."
Robert Pattinson began modeling at just 12-years-old but stopped a few years later, saying "I became too much of a guy, so I never got any more jobs."
Pattinson went on to become a teen hearthrob playing Edward Cullen in the "Twilight" franchise. He also starred in "Water for Elephants," "Cosmopolis," and the upcoming"Maps To The Stars." With his good looks in tact at age 27, the actor also became the face of Dior in 2013.
Before stripping down for her role as Mystique in 2000's "X-Men," Rebecca Romijn posed for Sports Illustrated's Swimsuit Issue and walked the runway for Giorgio Armani and Victoria's Secret.
In addition to her role in the "X-Men" franchise, Romijn has starred in a handful of TV series' such as "Eastwick," "King & Maxwell," and "Ugly Betty."
next slide will load in 15 secondsSkip AdSkip AdBrooke Shields started modeling before she was even a year old, appearing in an ad for Ivory Soap. Shields became the prodigy of Ford Models founder Eileen Ford, modeling for Calvin Klein Jeans at age 14 and becoming the youngest model to ever grace the cover of Vogue.
After becoming a teen star in "Blue Lagoon," Shields left the 'biz to attend Princeton University. She later returned to Hollywood and has starred on "Suddenly Susan," "Army Wives," and "The Middle."
James Marsden modeled for Versace before heading to Hollywood.
Marsden went on to star as Cyclops in "X-Men," "Superman Returns," "Hairspray," and even guest-starred on "30 Rock."
By age 15, Jaime King had appeared in Vogue and Seventeen. By age 18, she was walking runways for Chanel and Christian Dior.
next slide will load in 15 secondsSkip AdSkip AdKing currently stars on "Heart of Dixie" and has appeared in hit films such as "Sin City" and "Pearl Harbor."
Now see the real people portrayed by famous actors...