Leah Remini -- Screw Scientology ... I'm 'Dancing with the Stars'

Leah Remini is going from Dianetics to disco ... TMZ has learned, the famous ex-Scientologist will appear in the upcoming season of "Dancing with the Stars" ... and Snooki will be making her post-pregnancy debut along with her.

Sources close to production tell us, the former "King of Queens" actress is on the show.

As we reported, Remini recently underwent a very public split from the Church of Scientology after raising questions about the disappearance of church leader David Miscavige's wife Shelly.

Remini filed a missing persons report regarding Shelly's disappearance in July, demanding answers, and the Church was NOT pleased ... ripping the actress for her wanton betrayal.

FYI, police claim they made contact with Shelly in the wake of Remini's report and determined Remini's concerns were "unfounded." Eerie.

In addition to Remini and Snooki, our sources say Elizabeth Berkley, Amber Riley from "Glee," and Christina Milian will also be on the show.