Saitobaru kofungun (西都原古墳群?) is a group of three hundred thirty three kofuns or tumuli in Saito city, Miyazaki Prefecture, Japan. This is one of the largest kofun groups in Japan, and the largest group in Kyushu situated on a 70-meter hill composed of diluvium. It is located within the Saitobaru-Sugiyasukyō Prefectural Natural Park.
The Saitobaru kofungun or Burial Mounds were designated by the national government as a special historical site in 1952. The majority of the tumuli in Saitobaru have yet to be excavated and many remain wrapped in a veil of mystery. There are 311 elevated mounds, (31 keyhole-shaped mound (zenpo-koenfun (前方後円墳), unique to ancient Japan, 1 Houfun(方墳）, 279 circular type (empun (円墳)), kofuns) and 10 Yokoana (横穴) kofuns and 12 underground kofuns, the last being peculiar to southern Kyushu. The first scientific excavation was made in 1912. In 1952, Saito City Museum was founded, which was later changed to Miyazaki Prefectural Saitobaru Archaeological Museum.