The genus Perisoreus is a very small genus of jays from the Boreal regions of North America and Eurasia from Scandinavia to the Asian seaboard. An isolated species also occurs in north-western Sichuan of China. They belong to the Passerine order of birds in the family Corvidae. Species of Perisoreus jays are most closely related to the genus Cyanopica.

A jay is a member of a number of species of medium-sized, usually colorful and noisy, passerine birds in the crow family, Corvidae. The evolutionary relationships between the jays and the magpies are rather complex. For example, the Eurasian magpie seems more closely related to the Eurasian jay than to the East Asian blue and green magpies, whereas the blue jay is not closely related to either. The Eurasian jay distributes oak acorns, contributing to the growth of oak woodlands over time.