Kazusa (加津佐町 Kazusa-machi) was a town located in Minamitakaki District, Nagasaki Prefecture, Japan.
As of 2003, the town had an estimated population of 7,870 and a density of 322.81 persons per km². The total area was 24.38 km².
On March 31, 2006, Kazusa, along with the towns of Arie, Fukae, Futsu, Kitaarima, Kuchinotsu, Minamiarima and Nishiarie (all from Minamitakaki District), was merged to create the city of Minamishimabara.
Coordinates: 32°37′N 130°10′E / 32.617°N 130.167°E