1 of 9
Milo Ventimiglia joins This Is Us as Jack, returning to the small screen after stints on Gotham, Chosen, and Heroes. The Gilmore Girls alum, who played Jess Mariano for five years in the early 2000s, got his start in the '90s, making cameos in The Fresh Prince of Bel-Air, She's All That, and Sabrina, the Teenage Witch, before landing his first lead role in 2000's Opposite Sex (pictured above).
2 of 9
Mandy Moore stars opposite Milo Ventimiglia on This Is Us as Rebecca, a gig she took on 15 years after starting her acting career. The star, who made the transition to on-screen roles in the early 2000s with Dr. Dolittle 2, The Princess Diaries, and A Walk to Remember, first rose to fame as a singer. Pictured above in 1999, Moore dropped her first album, So Real, that year.
3 of 9
This Is Us found its Kevin in Mistresses and The Young and the Restless star Justin Hartley. Pictured above in 2003, the actor landed his first roles in the 2000s, picking up credits for Passions, Race You to the Bottom, and Smallville.
4 of 9
Chrissy Metz joins This Is Us as Kate. The actress' first on-screen role was in one 2005 episode of Entourage (pictured above), and she went on to make a name for herself with appearances in My Name Is Earl and American Horror Story.
5 of 9
Sterling K. Brown
Fresh off his Emmy win for The People v. O.J. Simpson: American Crime Story, Sterling K. Brown joins This Is Us as Randall. The star picked up his first on-screen credits in the 2000s, appearing in Brown Sugar, Third Watch, NYPD Blue, and Boston Legal (pictured above).
6 of 9
Susan Kelechi Watson
Susan Kelechi Watson signed on to play Beth in This Is Us, a gig she took on about 10 years after making her on-screen debut. Pictured above in 2005, Watson got her start in the 2000s, earning credits for Hack, Third Watch, and Law & Order: Trial by Jury.
7 of 9
After wrapping his run as The Knick's Tom Cleary, Chris Sullivan plays Toby in This Is Us. Pictured above in 2010, Sullivan appeared in TV movies and shorts in the late 2000s, going on to land roles in A Gifted Man, Elementary, and Law & Order: Special Victims Unit.
8 of 9
Ron Cephas Jones
Following his turns as Mr. Robot's Romero and The Get Down's Winston Kipling, Ron Cephas Jones joins This Is Us as William. Pictured above in 2003, Jones started acting in the '90s, racking up roles in Law & Order, He Got Game, and Sweet and Lowdown.
9 of 9
Decades into his career, Gerald McRaney plays a doctor in This Is Us. The actor built up his career in the '70s, earning credits for Gunsmoke, Barnaby Jones, The Rockford Files, and The Incredible Hulk (pictured above).