Dolichopodidae, the long-legged flies, are a large, cosmopolitan family of true flies with more than 7,000 described species in about 230 genera. The genus Dolichopus is the most speciose, with some 600 species.

Dolichopodidae generally are small flies with large, prominent eyes and a metallic cast to their appearance, though there is considerable variation among the species. Most have long legs, though some do not. In many species the males have unusually large genitalia which are taxonomically useful in identifying species. Most adults are predatory on other small animals, though some may scavenge or act as kleptoparasites of spiders or other predators.