used as a general-purpose exclamation; also as an intensification of a personal opinion UK,1925
“I thought I’d get clear on your involvement before I decided what to do.” Well, I’ll be damned. — Paula L Woods, InnerCityBlues, p. 27, 1999
Well, I’ll be damned if it’s a coincidence, a gas bomb, a violent robbery and an assault on the same day. — Paul Cornell, “HumanNature”, [a“DoctorWho”storypublishedontheBBCwebsite], August 2003