Sakai, Nagano

 was a village located in Higashichikuma District, Nagano Prefecture, 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, along with the villages of Honjō and Sakakita (all from Higashichikuma District), was merged to create the village of Chikuhoku.