Jennifer Garner
In the 2004 movie, Garner starred as the thirty, flirty and thriving Jenna Rink, who tries to navigate life as an adult after making a wish to be older at her 13th birthday party.
After wrapping Alias in 2006, she went on to star in a number of movies such as Juno, Dallas Buyers Club, Men, Women & Children, Miracles from Heaven, Love, Simon and Peppermint. Garner then made her return to TV in the 2018 HBO series Camping.
Ahead of 13 Going on 30's 15th anniversary in 2019, Garner appeared on Good Morning America, where she was asked about a possible movie sequel. "What like 15 Going on 50?" she joked. "Let's simmer down and then let's leave well enough alone."
In addition to being an actress, Garner is the co-founder of Once Upon a Farm. She's also mom to kids Violet, Seraphina and Samuel, who she shares with ex Ben Affleck.
Brie Larson
Did you know Larson was in 13 Going on 30? That's right, she was a Six Chick! Larson, who was just starting her career when the film premiered in 2004, also starred in the beloved teen movie Sleepover that same year. Since then, she's skyrocketed to superstardom, starring in the TV series United States of Tara from 2009 to 2011 and movies like 21 Jumpstreet, Trainwreck and Captain America.
In 2016, Larson won the Best Actress Oscar for her performance in the film Room.
Mark Ruffalo
Speaking of Avengers, Ruffalo is another 13 Going on 30 cast member who stars in the movie franchise. Ruffalo and Larson both appear in Avengers: Endgame.
In 13 Going on 30, he played the adult version of Matt Flamhaff, the best friend and love interest of Jenna. Ruffalo starred in a number of romantic movies around the same time as 13 Going on 30, making audiences swoon in films like Rumor Has It... with Jennifer Aniston and Just Like Heaven with Reese Witherspoon. Since then, Ruffalo has been nominated for four Oscars for his work in The Kids Are All Right, Foxcatcher and Spotlight. He nabbed a 2020 Emmy and a 2021 Golden Globe for his role in I Know This Much Is True.
He's been married to Sunrise Coigney since 2000 and the duo share three kids together.
Ashley Benson
Remember Benson in the movie? She was also a Six Chick with Larson. In 2004, the same year the film premiered, Benson began her role as Abby Deveraux in Days of Our Lives. In 2010, she shot to fame when she was cast as Hanna Marin in the beloved series Pretty Little Liars. Since the show's finale in 2017, Benson has starred in the movie Her Smell alongside Elisabeth Moss.
Her latest project? Motherhood. She and husband Brandon Davis welcomed their first baby together in Feb. 2024.
Judy Greer
Greer appeared as Garner's frenemy Lucy Wyman in the cult favorite. While they were at odds on the big screen, Garner revealed that she and Greer are still "really good friends" today.
She's since became known for her iconic characters in The Wedding Planner and 27 Dresses. Her impressively long resume includes films like 2011's The Descendants, 2013's Carrie and 2015's Jurassic World.
Andy Serkis
Serkis appeared as Jenna's boss at her dream magazine, Poise. Over the years, Serkis became known for his motion capture roles in The Lord of the Rings franchise. In 2011, he co-founded a motion-capture production company called The Imaginarium. The studio was used for the creation of 2018's Mowgli: Legend of the Jungle.
Christa B. Allen
Christa B. Allen's role in 13 Going on 30 was one of her first credited acting gigs. Following the film, Allen landed parts in shows like Wizards of Waverly Place and Grey's Anatomy. In 2009, Allen appeared as a teenage Jennifer Garner in the movie Ghosts of Girlfriends Past. From 2011 to 2015, Allen starred in the hit ABC drama series Revenge.
In November 2021, she officially turned 30 and we officially felt old.