"I was just listening to old-school stuff. I was listening to theater productions," Biel said about how she avoided listening to the group during their heyday. "I like lived under a rock. I just wasn't into pop culture music."
Fallon played for Biel an old interview of the actress from 1999 discussing 'NSYNC and how she wasn't a fan.
"I mean I know of them, of course, and I've heard of them and I've heard of the music. I don't think I own any of their CDs. I'm not a huge fan. But I mean, cool I guess," Biel's younger self said in the clip.
Biel also said that she was unable to perform an 'NSYNC song while recently playing a round of Truth of Dare with friends and needed help from Timberlake.
"It was humiliating," she told Fallon of the experience.
"Do you ever wonder what happened to O.J.'s white Bronco? Come on in, we'll show you," Fallon said during the skit.
Biel currently stars on Facebook Watch series Limetown.