Oh My Chad Share definition Flag A version of oh my god, originating in the Disney channel series Sonny With a Chance. Commonly used by screaming fangirls. Sometimes shortened to OMC. Person 1: Do you like the movie Starstruck? Person 2: Oh my Chad, it's amaing! Oh My Chad by thequeenofallruralsuburbia August 1, 2010 Get the Oh My Chad mug.