Barrymore wed long-time love Will Kopelman in front of family and friends, including Fallon and Cameron Diaz, over the weekend in Montecito, CA.
Late Night host Fallon opened up about the ceremony during an interview on The Billy Bush Show on Thursday (June 7)
"Drew had a beautiful wedding. Oh my gosh, she looked gorgeous and it was just perfect," the comic told Billy Bush.
Fallon also revealed that the reception was particularly fun because Barrymore hired an '80s cover band to perform live karaoke.
"I did hop on-stage with the band later on. I sang 'Jessie's Girl' and 'I Love Rock 'n' Roll'," he revealed. "The band was The Spazmatics, and they're an '80s cover band. They were so fun.
"They're great. They really are talented musicians, but they dress like nerds from the '80s."
Barrymore tied the knot wearing a pleated muslin and organza Karl Lagerfeld wedding dress, which designer Lagerfeld described as "perfect".
The Charlie's Angels actress and Kopelman confirmed on Thursday that they are expecting their first child.