Baetidae is a family of mayflies with about 1000 described species in 110 genera distributed worldwide.

Most species have long oval forewings with very few cross veins (see Comstock-Needham system) but the hindwings are usually very small or even absent.

The males often have very large eyes, shaped like turrets above the head (this is known as "turbinate condition").

The majority of living genera (approximately 95) are placed in the subfamily Baetinae Leach, 1815,[2] with the subfamily Palaeocloeoninae Kluge, 1997 consisting of the single genus †Palaeocloeon Kluge, 1997 from the Santonian aged Taimyr amber.

The oldest members of the family date to the Late Cretaceous, with Myanmarella and Vetuformosa known from the Cenomanian aged Burmese amber.