Seth Benjamin Green (né Gesshel-Green; born February 8, 1974) is an American actor. His film debut came with a role in the comedy-drama film The Hotel New Hampshire (1984), and he went on to have supporting roles in comedy films throughout the 1980s, including Can't Buy Me Love (1987) and My Stepmother Is an Alien (1988).
During the 1990s and 2000s, Green began starring in comedy films such as Can't Hardly Wait (1998), Rat Race, America's Sweethearts (both 2001), Scooby-Doo 2: Monsters Unleashed, and Without a Paddle (both 2004), and became known for his portrayal of Scott Evil, Dr. Evil's son, in the Austin Powers film series (1997–2002). Also during this time, he began taking more serious roles in action films, including Knockaround Guys (2001) and The Italian Job (2003). He has provided the voice for Howard the Duck in a number of Marvel Cinematic Universe films and series, including Guardians of the Galaxy (2014) and Guardians of the Galaxy Vol. 2 (2017). In 2019, he wrote, directed, and starred in the comedy-drama film Changeland.
Green's first lead role on television was on the ABC sitcom Good & Evil in 1991, for which he won a Young Artist Award. Green later gained attention for his supporting roles as Oz, a teenage guitarist and the boyfriend of Willow Rosenberg, on the fantasy television series Buffy the Vampire Slayer (1997–2000), and as the voice of Chris Griffin on the Fox adult animated sitcom Family Guy (1999–present). He also voiced Leonardo in the Nickelodeon animated series Teenage Mutant Ninja Turtles (2014–2017) and Joker in the Mass Effect video game series (2007–2012). Green created, directs, writes, and produces the adult animated comedy series Robot Chicken and its spinoffs (2005–present), which have earned him three Primetime Emmy Awards and five Annie Awards.