Their appearances will come a week after previously announced host Edward Norton and musical guest Janelle Monáe. Both will be making their first appearances on the show with the Oct. 26 episode.
Though Eminem has appeared as a musical guest five times before, this is also Washington’s hosting debut.
Washington brings an African-American female voice to the show at a time it is again being criticized for a lack of diversity. In an interview with TVGuide.com Monday, cast member Kenan Thompson said no black female comedians have been “ready” recently.
“It’s just a tough part of the business,” Thompson said. “Like in auditions, they just never find ones that are ready.”