Oscar nominee Franco announced his participation in March (13), revealing he will play intelligent field worker George Milton, who travels around California in search of work with his mentally disabled best friend, Lennie Small.
Irish actor O'Dowd is currently the frontrunner to portray Small in the new stage adaptation, which will be directed by Anna D. Shapiro, who won acclaim for her production of August: Osage County in 2007.
Of Mice and Men originally ran on Broadway in 1937 and was revived for the New York stage in the 1970s, with Kevin Conway and James Earl Jones leading the cast.
The new production is expected to begin previews in March (14) and open in April (14). It will also mark Franco's first time on Broadway.