Lady Gaga Confirms She Will Star in 'Joker' Sequel Alongside Joaquin Phoenix

Lady Gaga shared the title of the Joker sequel and release date — Oct. 4, 2024 — to social media on Thursday

Lady Gaga; Joaquin Phoenix. Photo: Eamonn M. McCormack/Getty Images; Steve Granitz/WireImage

Lady Gaga is officially onboard for Joker: Folie à Deux.

The 36-year-old actress and musician is set to star alongside Joaquin Phoenix in the upcoming musical sequel to 2019's Joker.

Gaga confirmed her casting on social media Thursday, posting an animated video of her and Phoenix's silhouettes set to old-timey music.

Along with the title, she shared the film's release date: Oct. 4, 2024.

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PEOPLE confirmed Gaga's involvement in the film — specifically, that she was in talks to play Harley Quinn — back in June.

The Hollywood Reporter was the first to share the news, reporting that Gaga's Harley would exist "in a different DC universe" than the one played by Margot Robbie in Suicide Squad (2016), Birds of Prey (2020) and The Suicide Squad (2020).

While plot and character details are still unknown, Harley — originally known as Dr. Harleen Quinzel — is villain Joker's love interest/sidekick in several iterations of the Batman story, and met the sinister prankster while serving as his psychiatrist at Gotham City's Arkham Asylum.

The film will see Todd Phillips (The Hangover) return as director, as well as co-writer alongside Scott Silver.

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Phillips, 51, alluded in June that a sequel to Joker — which broke box-office records as the first R-rated movie to hit the $1 billion mark in 2019 and earned 12 Oscar nominations, including a Best Actor win for Phoenix — was in pre-production on Instagram.

The two-part post opened with the red cover of a script titled Joker: Folie à Deux. The binder was dated May 18 and featured his name next to that of Silver, 57, with whom he also co-wrote the first Joker screenplay.

A second shot showed Phoenix, 47, casually reading the script on a couch while smoking a cigarette.

Folie à Deux, which references a delusion or mental illness shared by two people, also suggests that Joker may also team up with another supervillain – possibly his sometime-girlfriend Harley.