Wordorigins.org

These two interjections have both been popularized by cartoons.

The first, doh, has been made famous by Homer Simpson, but he was not the first to use it. That honor goes to James Finlayson, who appeared with the comedians Laurel and Hardy in several films. This dialogue is from the 1931 Pardon Us, Laurel and Hardy’s first full-length film:

Professor Finlayson: How many times does three go into nine?
Stan: Three times.
Finlayson: Correct.
Stan: And two left over.
Finlayson (to Ollie): What are you laughing at?
Ollie (snickering): There’s only one left over.
Finlayson: D-ohhhh!¹