After moving to Los Angeles at age 25, Oteri worked at A&M Records for four years and eventually joined famed comedy troupeThe Groundlings. In 1995, producers of Saturday Night Live attended a performance with the intention of auditioning fellow Groundlings member Chris Kattan. Oteri performed a monologue during one of Kattan's costume changes, which led to her own invitation to audition for SNL, along with Kattan and fellow Groundling Will Ferrell. She was hired as a repertory performer in September 1995 as part of an almost entirely new cast, which was brought in after the show's disastrous 1994–1995 season. She has also appeared in several movies, including Scary Movie, Inspector Gadget, Liar Liar, , Shrek the Third and Southland Tales. She starred in two TV pilots that did not make it to air: Loomis and With You in Spirit. She has also made guest appearances on television shows, such as Just Shoot Me!, Strangers with Candy and as Martine, the emotionally unstable nanny on Curb Your Enthusiasm. In 2009, Oteri became a regular voice cast in the Foxanimated comedy series, Sit Down, Shut Up. She voices Helen Klench, the unappreciated librarian who often gets mistaken for objects, such as brooms or toilet brushes. The series premiered on April 19, 2009 and moved to Comedy Central in May 2010. She also played a tooth fairy on Imagination Movers, a regular on the Playhouse Disney block. She starred in the AMCweb seriesLiza Life Coach in 2010. Oteri appeared in the pilot episode of Glory Daze, which premiered on TBS on November 16, 2010. She hosted AXS TV's Gotham Comedy Live on May 26, 2016 in New York City. Oteri reprised her role as Barbara Walters on the CNN special New Year's Eve Live 2020. Host Anderson Cooper doubled over in laughing fits during her monologue as Walters.
Nadeen, a testy employee whose catchphrase constantly orders everyone to "Simmer down now!"
Althea McMahonaman, an absurdly hyper child who is an awful passenger and disturbs public servants
Collette Reardon, a prescription pill-addict
Joy Lipton, Erotic Attic boutique owner
Adele, a vulgar and highly sexual office worker whose attempts at sexual innuendos disgust rather than attract her colleagues.
Laura Zimmerman, one half of the Zimmermans, who suddenly break into rough and sexual behavior before returning to casual conversation as if nothing happened