Writer-director Xavier Dolan, actor Cherry Jones and music artist Troye Sivan have also come on board the film, reported Variety.
The movie will see Russell Crowe, Nicole Kidman and "Manchester by the Sea" break out Lucas Hedges in the lead roles.
Hedges will star as the son of a Baptist minister that is outed by his parents (played by Kidman and Crowe) and forced into conversion therapy.
Edgerton will write, direct, and also star in the movie, that will begin production this fall for a 2018 theatrical release.