The 28-year-old hottie has popped the question to the equally hot Dewan, 27, her rep confirmed to E! News.
The deed went down on Friday while the couple was in Maui, according to People magazine, which first reported the betrothal. To the bride-to-be's surprise, Tatum had invited their close friends to the island to witness the proposal.
The pair met in 2005 on the set of the hit dance movie Step Up and started dating after the film wrapped.