Sanwa (三和町; -machi) is a town located in Sashima District, Ibaraki, Japan.
As of 2003, the town has an estimated population of 39,220 and a density of 787.87 persons per km². The total area is 49.78 km².
On September 12, 2005 Sanwa was merged with the town of Sōwa, also from Sashima District, and the former city of Koga to form the new city of Koga.