The stage version borrows the 2007 movie's songs by Glen Hansard and Markéta Irglová, who also played the would-be lovers in the film. The Broadway production, which premiered in 2012, won eight Tony Awards including Best Musical.
Melbourne performances begin Sept. 26 at the Princess Theatre.
Once has a book by Irish playwright Enda Walsh ( Penelope), direction by John Tiffany ( Black Watch), movement by Steven Hoggett ( American Idiot, Black Watch) and set and costume design by Tony Award winner Bob Crowley ( The Coast of Utopia, Mary Poppins).
In addition to Parsons ( Jesus Christ Superstar) and Jones ( Equus), the cast of actor-musicians will include Anton Berezin, Andrew Broadbent, Ben Brown, Gerard Carroll, Colin Dean, Brent Hill, Stefanie Jones, Keegan Joyce, Amy Lehpamer, Lachlan Neate, Jane Patterson, Greg Stone, Susan-ann Walker and Paul Watson.
According to producers, " Once tells the enchanting tale of a Dublin street musician who’s about to give up on his dream when a beautiful young woman takes a sudden interest in his haunting love songs. Emotionally captivating and theatrically breathtaking, it draws you in from the very first note and never lets go."