Ryūzōji clan (Japanese: 龍造寺氏, Hepburn: Ryūzōji-shi) was a Japanese kin group which traces its origin to Hizen Province on the island of Kyushu.

[1] The clan was founded by Fujiwara no Suekiyo in 1186.

[1] Ryūzōji Takanobu is known for expanding his clan's holdings.

In 1587, Masaie joined the forces of Toyotomi Hideyoshi against the Shimazu clan.

In the same year, he was confirmed as head of the Saga Domain (350,000 koku), but control of the domain passed to Nabeshima Naoshige[3] when Masaie was killed in battle.