Sakai (坂井村 Sakai-mura) was a village located in Higashichikuma District, Nagano, Japan.
As of 2003, the village had an estimated population of 1,588 and a density of 42.45 persons per km². The total area was 37.41 km².
On October 11, 2005 Sakai was merged with the villages of Honjō and Sakakita, all from Higashichikuma District, to form the new village of Chikuhoku.