Tomigusuku Ueekata Seizoku (豊見城 親方 盛続, 1520 – 28 May 1622), also known by his Chinese style name Mō Keiso (毛 継祖), was a bureaucrat of Ryukyu Kingdom.
Tomigusuku Seizoku was born to the aristocratic Mō-shi Tomigusuku Dunchi (毛氏豊見城殿内) family. He was the eldest son of Tomigusuku Seishō (豊見城 盛章, also known as Mō Ryūbun 毛 龍文), whom served as a member of the Sanshikan during Shō Ei and Shō Nei's reign.
Seizoku put down the rebellion of the Jana family (謝名一族) together with two generals, Ikegusuku Anrai and Mabuni Ankō (摩文仁 安恒, also known as Kin Ōku 金 応煦). All of them received ueekata, the highest rank in the yukatchu aristocracy of Ryukyu.
Ming China sent a mission for the investiture of King Shō Nei in 1606. Concerned about the rampant wakō pirates, King Shō Nei dispatched an army led by Seizoku to defend Nakijin Castle.
Satsuma Domain invaded Ryukyu in the spring of 1609. When Satsuma troops approached Naha, Gushichan Chōsei led a mission to hold peace talks at Oyamise (親見世). Tomigusuku Seizoku, Kikuin, Kian, Ikegusuku Anrai, Esu Seishō (江洲 盛韶) and Tsuken Seisoku (津堅 盛則) were sent as assistants. Neither Kabayama Hisataka nor Hirata Masumune appeared at the peace talk, and the peace proposal was rejected by Satsuma.