“D’oh” is Homer Simpson’s signature expression of frustration in the animated television series The Simpsons. Voice actor Dan Castellaneta performs the brief grunt, which appears whenever Homer recognizes a mistake, setback, or painful consequence. The series began airing as a standalone program in 1989, helping the expression become widely recognized through television reruns, quotes, and online clips. Its compact timing and clear emotional meaning later made it useful in reaction memes, gaming edits, short videos, and comedic failure compilations.