Ōizumi (大泉村 Ōizumi-mura) was a village located in Kitakoma District, Yamanashi, Japan.
On November 1, 2004 Ōizumi was merged with the towns of Hakushū, Nagasaka, Sutama and Takane, and the villages of Akeno and Mukawa, all from Kitakoma District, to form the new city of Hokuto.
As of 2003, the village had an estimated population of 4,155 and a density of 65.88 persons per km². The total area was 63.07 km².