The story
Earliest known use is from 1949 in Dan Levin's Mask of Glory.
First known use, by meaning
- from mid-20th c. Synonym of I kid you not (Used to insist that one is telling the truth)
Etymology from Wiktionary, CC BY-SA 4.0.
I shit you not
Today it means: Synonym of I kid you not (Used to insist that one is telling the truth) Full definition →
First used mid-20th c.