Muikamachi, Niigata

 was a town located in Minamiuonuma District, Niigata Prefecture, Japan.
As of 2003, the town had an estimated population of 28,687 and a density of 108.75 persons per km². The total area was 263.79 km².
Muikamachi was a popular destination for skiers.
On November 1, 2004, Muikamachi, along with the town of Yamato (also from Minamiuonuma District), was merged to create the city of Minamiuonuma.