Limnocyon ("swamp dog") is an extinct paraphyletic genus of limnocyonin hyaenodonts that lived in North America during the middle Eocene. Fossils of this animal have been found in California, Utah and Wyoming.

Limnocyon was a small omnivorous hyaenodontid, with some estimates placing it at less than 1 kg in weight. Like other limnocyonins, Limnocyon had only two molars in the upper and lower dentition.