Uenohara is located in the extreme eastern edge of Yamanashi Prefecture, on a fluvial terrace of the Sagami River.

During the Nara period ritsuryo organization of Kai Province, the area came under Tsuru County.

During the Edo period, all of Kai Province was tenryō territory under direct control of the Tokugawa shogunate.

After the Meiji restoration, the village of Uenohara was established on December 27, 1897 with the creation of the modern municipalities system.

Uenohara has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 16 members.