Saturday Night Live aired its third season during the 1977–1978 television season on NBC. The season began on September 24, 1977 and ended on May 20, 1978. The DVD for the entire season was released on May 13, 2008.

The entire cast from the previous season returned for season three. The show also introduced the concept of the "featured player." Writers Tom Davis and Al Franken became cast members.

The season is also notable for the contest, Anyone Can Host. During the start of the season the show advertised the contest for a non-celebrity to host the show. The winner was 80 year-old grandmother Miskel Spillman, the only non-celebrity to host an SNL episode. During Spillman's show the musical guest, Elvis Costello, halted his band, the Attractions, seven seconds into the song "Less Than Zero", launching into "Radio Radio", an as-yet unreleased song critical of mainstream broadcasting. The change angered Lorne Michaels, who banned future appearances on the show for a while.

Chevy Chase's hosted during the season, making him the first cast member to host after leaving the show. Backstage during the show Chase and Bill Murray engaged in a physical altercation that was broken up by John Belushi and Dan Aykroyd. Chase later accused Murray of trying to upstage him on set and for making explicit remarks about Chase's wife. Chase would host the show several times throughout the show's history, though he was unpopular with the cast and crew.