The former Beatles drummer and Eurythmics musician are working together on a musical titled Hole in the Fence.
The project will be a coming-of-age story about a group of children who form a band in order to escape their mining town, reports Deadline.
David Harris, who is also currently adapting the graphic novel Zombie Broadway with Stewart, will pen the screenplay.
Starr and Stewart will also act as executive producers for the film.
Ringo Starr released his 17th solo studio album Ringo 2012 in January.
Sir Paul McCartney's son James McCartney recently revealed that a new generation of The Beatles featuring the original members' sons could be formed.