Saturday Night Live had its thirtieth season on the 2004-2005 television season on NBC. The thirtieth season began on October 2, 2004 and ended on May 21, 2005 with 20 episodes in all.

Before the start of this season, Jimmy Fallon left the show. In the wake of his departure, Fred Armisen was promoted to repertory status, while Finesse Mitchell and Kenan Thompson remained feature players.

New cast members this season include Rob Riggle, an improv comedian and U.S. Marine. This would be Riggle's only season on the show. In addition, SNL writer Jason Sudeikis joined the cast as a featured player for the last three episodes of the season.

With Fallon gone, Amy Poehler became Tina Fey's co-anchor on Weekend Update, making Fey and Poehler the first two-woman anchor team.

This season was also notable for Ashlee Simpson's infamous lip-syncing gaffe during her second performance. This season was also home to many sketches focused on the 2004 U.S. Presidential election, but, unlike the 2000 election, there was little to no media coverage about the sketches.