The film picks up eight years after the original was released, in which Sophie (Amanda Seyfried) learns about her mother's (Meryl Streep) interesting past while she herself is pregnant.
Amanda looked gorgeous in an all-black ensemble with roses that strategically adorned the jacket.
Lily James, who plays the younger version of Meryl's character Donna, blended in with the colors of the carpet and backdrop in a gorgeous white and blue dress.
Meryl looked effortlessly chic in her loosely fitting dark blue outfit.
Cher, who plays Meryl's mother in the sequel (they are only 3 years apart in real life), opted to dress in all black for the film's premiere.
Other celebs who made it to the premiere included Westworld star Thandie Newton, Tom Hanks and Rita Wilson. The film opens nationwide July 20.
Who was your pick for best dressed last night? Sound off in the comments!