Joan Lea Bybee (previously: Hooper; born 11 February 1945 in New Orleans, Louisiana ) is an American linguist and professor emerita at the University of New Mexico.
She served as president of the Linguistic Society of America in 2004.
Much of her work concerns grammaticalization, stochastics, modality, morphology, and phonology.
She is best known for proposing the theory of Usage-based phonology and for her contributions to cognitive and historical linguistics.