When hedonistic but charming con man Elmer Gantry meets the beautiful Sister Sharon Falconer, a roadside revivalist, he feigns piousness to join her act as a passionate preacher. The two make a successful onstage pair, and their chemistry extends to romance. Both the show and their relationship are threatened, however, when one of Gantry's ex-lovers decides that she has a score to settle with the charismatic performer.