London, UK - Pop star Lady Gaga shut the red carpet down at the London premiere for the anticipated sequel Joker: Folie à Deux!

Oh, puddin'! The 38-year-old entertainer has officially entered her Harley Quinn era.

Gaga had the crowd going "gaga" over her attire at the London premiere of the upcoming thriller-musical.

The Bad Romance singer stunned in a dramatic red gown, complete with a plunging neckline line and pleated skirt.

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Gaga, who was born Stefani Germanotta, added a matching, cropped long-sleeve jacket with puffy sleeves, and while her theatrical makeup consisted of bright-blue eye shadow and crystal teardrops was a nod to her Joker character.

The Oscar nominee was joined by her costar, Joaquin Phoenix, plus her fiancé Michael Polansky – who looked dashing in a classic black suit and was captured kissing his bride-to-be.

Gaga and Phoenix will portray Harley Quinn and Arthur Fleck in the anticipated sequel to the 2019 Oscar-winning film.

The Poker Face hitmaker just announced her next album, Harlequin, will drop on September 27 and is a companion album to Joker: Folie á Deux, which theaters October 4!