Wiig was the guest of honor in a televised graduation ceremony that marked the end of the show's 37th season and her finale as a member of the cast.
The scene was emceed by Rolling Stones frontman Mick Jagger, who singled out Wiig, who is moving on to movies. "Many of you are moving onto college, but I'd like to take a moment to say goodbye to one particular student who is leaving this summer … to become a nun," Jagger joked.
Wiig doffed her cap-and-gown costume and danced with her castmates while Arcade Fire played the Stones classic "She's a Rainbow." The rising actress wore a mixed expression of tears and smiles, the New York Post said.