At 13-years-old he played Alyson Hannigan's boyfriend 'Fred' in My Stepmother Is an Alien (1988). Ten years later, at the age of 23, he played her boyfriend again when he landed the role of 'Oz' on the TV show "Buffy the Vampire Slayer" (1997).
Not many people know that he was responsible for one of the most overused catchphrases of the 1990s. In 1992 he appeared in a commercial for Rally's Burgers as an obnoxious drive-thru cashier who kept repeating the line "Cha-CHING!!" over and over again and the line entered the popular culture.
Along with Chi Muoi Lo, he is one of only two actors to appear in both Buffy the Vampire Slayer (1992) and the subsequent television adaptation "Buffy the Vampire Slayer" (1997). However, his scenes in the former were cut from the final version of the film.
He had a part filmed for Buffy the Vampire Slayer (1992); the part was left on the cutting room floor, but a still from the scene appeared on the rear of the commercial release videocassette box. Seth eventually got to be in Buffy, though, on the TV series.
Seth is not related to Bruce Seth Green, who directed some episodes of "Buffy the Vampire Slayer" (1997). On occasion, some sources confuse the two and have credited Seth as the director.
At the same time he was offered the part in Austin Powers: International Man of Mystery (1997), he was also offered a role in Chairman of the Board (1998), starring Scott 'Carrot Top' Thompson. Seth said making the choice between the two films was difficult at the time. [source: Seth Green interview on NPR, Feb 23, 2005].
1998: Named on Entertainment Weekly's "It List" of the 100 Most Creative People in Entertainment.
Seth is thanked in the sleeve notes of Blink 182's "Enema of the State". Blink also thanks Idle Hands (1999) and Can't Hardly Wait (1998) -- both movies featuring a Blink 182 song and coincidentally both have Seth Green in them. Seth also had an uncredited role in Enemy of the State (1997).
Based the gravelly voice of Chris Griffin in "Family Guy" (1999) on the Buffalo Bill character from The Silence of the Lambs (1991).
Revealed in a 2005 "Fresh Air with Terry Gross" interview that he had auditioned for the American Beauty (1999) role that eventually went to Wes Bentley, and he was the runner-up for the Eternal Sunshine of the Spotless Mind (2004) role that went to Elijah Wood.
He played Lyle in The Italian Job (2003). His Austin Powers in Goldmember (2002) co-star Michael Caine appeared in the original The Italian Job (1969).
Named #7 of the Top Ten Sexiest Men of the Buffy / Angel universe in a fan poll by the Buffy the Vampire Slayer fanzine (2004).
Has made his entrance in two separate films to two separate Clay Aiken songs. They are "Invisible" in Without a Paddle (2004) and "The Way" in Scooby Doo 2: Monsters Unleashed (2004).
Has been long time friends with actress Sarah Michelle Gellar, and has collaborated with her quite a few times. They can be found together in Scooby Doo 2: Monsters Unleashed (2004), "Buffy the Vampire Slayer" (1997) and "Robot Chicken" (2005).
Engaged to Clare Grant [February 25, 2010].