The Uesugi clan were descended from the Fujiwara clan and particularly notable for their power in the Muromachi and Sengoku period . The clan was split into three branch families, the Ōgigayatsu, Inukake and Yamanouchi Uesugi, which boasted considerable influence. The Uesugi are perhaps best known for Kenshin Uesugi, one of Sengoku's more major warlords. The family name is sometimes rendered as Uyesugi, but this is representative of historical kana usage; the "ye" sound is no longer used in Japanese.
In the Edo period, the Uesugi were identified as one of the tozama or outsider clans, in contrast with the fudai or insider daimyō clans which were hereditary vassals or allies of the Tokugawa clan.