The Great God Brown is a 1926 play by Eugene O'Neill. It is noted for its use of masks.
The play was included in Burns Mantle's The Best Plays of 1925-1926.
Dion Anthony and his friend William A. "Billy" Brown are sons of business partners. Both love Margaret, but she falls in love with Dion when he is presented behind a cruel and cynical mask, even though he is a sensitive artist. After the two men inherit the business, Dion retires to paint, but fails and eventually dies. Billy takes the mask and poses as Margaret's husband. By the time she finds out, the "real" Billy has faded away. Brown is accused of killing his "real" self, and only the unmasked prostitute Cybel is there to comfort him. Eventually Billy dies as well, and years later Margaret pledges her undying love to Dion's mask.