Earworm, a loan translation of the German Ohrwurm, is a portion of a song or other music that repeats compulsively within one's mind, put colloquially as "music being stuck in one's head."

Use of the English translation was popularized by James Kellaris, a marketing researcher at the University of Cincinnati, and Daniel Levitin. Kellaris' studies demonstrated that different people have varying susceptibilities to earworms, but that almost everybody has been afflicted with one at some time or another.

According to research by James Kellaris, 98% of individuals experience earworms. Women and men experience the phenomenon equally often, but earworms are more likely to last longer for women and to irritate them more than men.