White recently revealed that she had landed the gig after a Facebook campaign urged Michaels to consider her.
USA Today reports that White will join former cast members Tina Fey, Amy Poehler, Molly Shannon, Maya Rudolph, Ana Gasteyer and Rachel Dratch for the Mother's Day episode, but will remain the show's solo host.
Michaels explained that he had "always wanted" the 88-year-old to appear on the show, adding: "[The campaign] took on a groundswell. It isn't something we would have said no to, [but it] validated that, 'Oh, that'd be fun'... It was the outpouring of affection from fans, and we feel the same way."
He also claimed that White is perfect for a Mother's Day edition of the programme, explaining: "She's the mother of us all in comedy, so it will be a celebration of Betty White."