According to Charles Funk, in Heavens to Betsy! & Other Curious Sayings, Harper & Row (1955), several theories have been advanced to explain “Heavens to Betsy,” but none to his satisfaction, and he deems the phrase “source unknown.”

Suggestions include: (1) a corruption of the French phrase, “auvergne betisse,” meaning “what won’t they think of next?”, and (2) some derivation from the frontiersman’s rifle or gun, which was commonly called Betsy for no apparent reason.