McAdams, always a red carpet stunner who rarely fails to impress, looked gorgeous in a pale, strapless dress while Tatum dressed up his beefy body in a gray suit.
Tatum's wife, actress and dancer Jenna Dewan, looked very Valentine's Day-ish in a ruffled pink dress.
The Vow is about a woman (McAdams) whose memories of her husband (Tatum) are wiped out after a car accident.
He tries to win her back after some serious courtship.
The movie should make for quite the Valentine's Day hit. It will be released in theaters on Friday, Feb. 10.
Tatum's upcoming films include G.I. Joe: Retaliation and the male stripper saga Magic Mike. Both are scheduled for release on June 29. His comedic film with Jonah Hill, 21 Jump Street, hits theaters on March 16.
McAdams will be seen in an upcoming, untitled film directed by Terrence Malick. Her costars include Rachel Weisz, Jessica Chastain and McAdams' main squeeze Michael Sheen.
Check out the movie trailer and photos from the premiere!