Jenna Dewan Says Janet Jackson Took Her Clubbing When She Was 18

Jenna Dewan says she had wild, crazy, and insanely amazing times clubbing with Janet Jackson when she was barely legal.

In a guest appearance on the "Chicks in The Office" podcast, Jenna recalled her crazy club-hopping days as a backup dancer on Janet's world tour ... saying Janet would sneak her into clubs, because she was only 18 years old when the tour started.

As the youngest backup dancer by far -- the next youngest was at least 6 years older -- Jenna says she was "the baby" on tour and was thrust into an entirely different world than she was used to in college.