Sanwa, Ibaraki

 was a town located in Sashima District, Ibaraki Prefecture, Japan.
As of 2003, the town had an estimated population of 39,220 and a density of 787.87 persons per km². The total area was 49.78 km².
On September 12, 2005, Sanwa, along with the town of Sōwa (also from Sashima District), was merged into the expanded city of Koga.