Saga (säˈgä) [key], city (1990 pop. 169,963), capital of Saga prefecture, W Kyushu, Japan. It is a railroad and coal-distribution center. Cotton textiles and ceramics are produced in the city. A castle town in feudal times, Saga was the center of a rebellion in 1874. Saga prefecture (1990 pop. 877,865), 946 sq mi (2,450 sq km), is known for its advanced techniques in growing rice and oranges, as well as for its dairy farming and cattle raising.