Sadamitsu (貞光町 Sadamitsu-chō) was a town located in Mima District, Tokushima, Japan.
On March 1, 2005 Sadamitsu was merged with the town of Handa, and the village of Ichiu, all from Mima District, to form the new town of Tsurugi.
As of 2003, the town had an estimated population of 5,718 and a density of 125.95 persons per km². The total area was 45.40 km².