Black is known for appearing on VH1's I Love The... series, his Stella comedy troupe, and a variety of other TV series and films. He was also the voice actor behind the Pets.com sock puppet, is the main subject in the current Sierra Mist commercials, hosted the first season of NBC's hidden-camera show Spy TV, and had a supporting role on the NBC dramedy Ed.
He began his career as a member of the comedy group The State and was featured on the television show by the same name on MTV. He continued working with members of that group on the show Viva Variety in the role of "Johnny Bluejeans", and in the film Wet Hot American Summer. His dry, sarcastically irreverent commentary on pop culture artifacts on VH1's "I Love the 70s/80s/90s" series has added to his and the shows' popularity. Black has stated several times on the show that he feels as if he is "doomed to an eternity of doing the 'I Love the...' series". He also makes fun of himself for being a Jewish-American and sarcastically enforcing the Jewish stereotypes.
In the latter part of 2004, he acted as guest-host of CBS's The Late Late Show while auditioning for the permanent hosting role. He was a finalist for the position, although the job eventually went to Craig Ferguson. He is also an occasional contributor to the online edition of McSweeney's, where he writes a column entitled "Michael Ian Black Is A Very Famous Celebrity".
Black, along with fellow State-rs Michael Showalter and David Wain, co-starred in and co-wrote the Comedy Central series Stella, a television adaptation of their popular stage show. The ten-episode first season debuted in June 2005 and was not renewed for a second season. He also appeared on the Comedy Central shows Crank Yankers and Reno 911!. In 2005, Black wrote and directed the film The Pleasure of Your Company, starring Jason Biggs, Joe Pantoliano, and Isla Fisher. The film is scheduled to be released in 2007 (The title has been changed to "Wedding Bliss". He also appeared twice on Adult Swim's show Tom Goes to the Mayor, as well as on Seth Green's stop-motion show Robot Chicken to which he lent his voice. He also had a cameo in David Wain 2007 film, The Ten as a prison guard.