O'Malley's first role came as the host of Nickelodeon children's game show "Get the Picture" when he was 24 years old, later moving on to "Nickelodeon Guts" and later "Global GUTS" from 1992 to 1995. On the advice of Marc Summers, O'Malley moved to Los Angeles after the cancellation of "GUTS" to further pursue his acting career. O'Malley starred in "Life with Roger", a series which aired from 1996 to 1997. In 1999, two of thirteen filmed episodes of "The Mike O'Malley Show" aired before the show was canceled. During the 1990s, he also appeared as "The Rick", a character in a series of ads for the ESPN network. In 2018, The Rick made a return in ads for the ESPN+ streaming service.