The 25-year-old singer and 37-year-old rapper are confirmed for the musical roster, along with Justin Timberlake, Paul McCartney and Paul Simon. The NBC sketch comedy series announced the news on Twitter and in a Super Bowl spot ad Sunday.
Former cast members Amy Poehler, Tina Fey and Kristen Wiig will make appearances, along with Chevy Chase, Dan Aykroyd and Bill Murray. Former hosts Alec Baldwin and Christopher Walken are also confirmed, and Eddie Murphy will return to the series for the first time in 21 years.
"It just never worked out where the timing was right for me to do it," the actor told News One last week. "They're actually having a 40th anniversary I think in two weeks. I'm going to that, and that'll be the first time I've been back since I left."
Saturday Night Live debuted as NBC's Saturday Night in 1975. The series currently stars Taran Killam, Kate McKinnon and Jay Pharoah, among others, and will air its 40th anniversary special February 15 at 8 p.m. ET.
Swift last released 1989 in October 2014, and announced Haim will join her 1989 World Tour on Sunday. West famously interrupted the singer during her acceptance speech at the 2009 MTV Video Music Awards.