The Alosidae, or the shads, are a family of clupeiform fishes. The family currently comprises four genera worldwide, and about 32 species.

The shads are pelagic (open water) schooling fish, of which many are anadromous or even landlocked. Several species are of commercial importance, e.g. in the genus Alosa (river herrings), Brevoortia (menhadens), and Sardina. The Alosidae were previously included in the herring family Clupeidae.

Alosidae contains the following 4 genera:

The following fossil Alosidae are also known:

The oldest member of the group is Pugliaclupea from the Campanian of Italy, but its placement in the Alosidae appears to be on weak grounds. Otherwise, all other members of the family are only known from the Eocene onwards. There appears to have been a significant center of endemism for the alosids and other clupeoids in the Paratethys. The freshwater †Chasmoclupea from the Oligocene of Egypt may also be related to the Alosidae.

While the hearing of most fishes is limited in frequency to less than 1 kHz, some shads and menhadens demonstrate an unusual ability to detect very high frequency sound (ultrasound) above 50 kHz