Green's first lead role on television was on the ABC sitcom Good & Evil in 1991, for which he won a Young Artist Award.

Seth Benjamin Gesshel-Green was born in Overbrook Park, Philadelphia, Pennsylvania,[1] the son of Barbara (née Gesshel) and Herbert Green.

[6] His early comic influences included Monty Python, Blackadder, Saturday Night Live, Richard Pryor, Bill Cosby, Porky's, and Caddyshack.

He appeared in the 1987 film Can't Buy Me Love, playing Patrick Dempsey's character's little brother, Chuckie Miller.

In 1984, Green portrayed Carl "Alfalfa" Switzer in the Jell-O Gelatin Pops commercials featuring The Little Rascals.

In 1991, Green rose to fame in a Rally's "Cha Ching" commercial,[9][10] which earned him an appearance at a New Orleans Saints game.

[11] Green appeared in the horror TV series It (as Richie Tozier, age 12) and Ticks, all three Austin Powers films (as Dr.

He played Daniel "Oz" Osbourne, a calm, mild-mannered member of the band Dingoes Ate My Baby who gets turned into a werewolf.

[13] He has stated that his main inspiration for Chris' voice came from envisioning how Buffalo Bill would sound when speaking through a public address system at a McDonald's.

[14] Green provides the voice of Howard the Duck for the live-action Marvel Cinematic Universe (MCU) films Guardians of the Galaxy (2014) and Vol.

Green is friends with the band Fall Out Boy, making a cameo in their music video, "This Ain't a Scene, It's an Arms Race".

Green and Robot Chicken co-producer Breckin Meyer appeared in the NBC show Heroes during the 2008–09 season.

On July 13, World Wrestling Entertainment's official website announced Green as the special guest host for the July 13 episode of WWE Raw, and on that night, Green competed in the main event, a six-man tag team match, which his team won by disqualification.