The forty-second season of the NBC sketch comedy series Saturday Night Live premiered on October 1, 2016, during the 2016–2017 television season, with host Margot Robbie and musical guest The Weeknd, and concluded on May 20, 2017, with host Dwayne Johnson and musical guest Katy Perry. The season removed two commercial breaks per episode in order to increase programming time. Episode 18 on April 15, 2017, was the first episode to be broadcast live in all four time zones within the contiguous United States. Until this episode, the show aired live only in the Eastern and Central time zones, and was tape-delayed in the Mountain and Pacific time zones.

NBC announced prior to the season that SNL would contain 30% less advertisement time starting with this season. Additionally, select NBC advertising clients will be given the opportunity to have their brand appear in promotional sketches, called "pods". Six of these pods will air each season.

Prior to the start of the season, longtime cast members Taran Killam and Jay Pharoah, as well as featured player Jon Rudnitsky, were released from the cast. Killam, despite having signed a seven-year contract that would have taken him to the end of this season, was dropped from the cast due in part to issues concerning his work directing the film Killing Gunther, which would have limited his time on the show. Following Killam, Pharoah, and Rudnitsky's departures, the show added three new featured players: SNL staff writer and Wild 'n Out alum Mikey Day of The Groundlings, Chicago improviser Alex Moffat, and stand-up comedian and impressionist Melissa Villaseñor. Contrary to rumors, stand-up comedian Chris Redd was not hired this season, but he did join the show as a featured player during the following season. Michael Che, Pete Davidson, and Leslie Jones were all upgraded to repertory status.

On June 24, 2016, Lorne Michaels announced that Michael Che and Colin Jost would continue as the anchors of "Weekend Update". Both were featured on SNL special editions of "Weekend Update" for the Democratic and Republican Conventions.

Though not a member of the cast, it was announced on September 28, 2016, that Alec Baldwin signed through this season to take over impersonating Donald Trump from Darrell Hammond, who continued on as the show's announcer.

This was the final season for longtime cast members Vanessa Bayer (who had been with the show for seven seasons since 2010), Bobby Moynihan (nine seasons since 2008), and Sasheer Zamata (four seasons since 2014).

bold denotes "Weekend Update" anchor

Prior to the start of the season, short film director Matt Villines (of the directing duo Matt & Oz) died of cancer.