Giamatti has signed on to play the manager of the rock band headed by Cruise's Stacee Jaxx character, in New Line's adaptation of the Broadway musical.
Director Adam Shankman is also courting actress Amy Adams for the role of a journalist who beds Stacee Jaxx, Deadline reports. The role was originally offered to Anne Hathaway, who turned it down because of her prior commitment to "The Dark Knight Rises," portraying Catwoman.
Shankman, who also directed the musical film re-make of "Hairspray," announced on his Twitter on Wednesday that "Rock of Ages" would be released on June 1, 2012 and that rehearsals will start in two weeks. The Twitter-happy director also announced Baldwin's inclusion in the cast on the micro-blogging social network site.
Baldwin will be playing the role of Dennis Dupree, an ex-rocker who runs the Rock of Ages nightclub and can't let go of the past.
On Thursday, it was confirmed that "Dancing With the Stars" professional Hough would play opposite Cruise as Sherrie, a small-town girl who catches the eye of Cruise's character Stacee Jaxx, a rock star at the top of his career. Hough may also be seen in some provocative outfits since the character of Sherrie becomes a stripper.
The film will be based off the hit Broadway musical which featured classic 80s hair rock hits from bands like Journey, Bon Jovi, and Twisted Sister. Cruise's character is expected to sing Bon Jovi's "Wanted Dead or Alive." The character is also a part of other numbers including Foreigner's "I Wanna Know What Love Is." The Broadway musical starred "American Idol" alum Constantine Maroulis.
The film is slated to begin shooting in May. Mary J. Blige has also signed on to the project to play a character called Justice and Russell Brand is rumored to be joining the cast.
Giamatti currently stars in "Win Win," which came out on March 18. The actor took home a Golden Globe Award for his work on "Barney's Version" and will star in the upcoming HBO movie "Too Big Too Fail," playing Ben Bernanke. Giamatti also worked on "The Ides of March," which was directed by George Clooney.