Hojo Yasutoki (北条 泰時 Hōjō Yasutoki; 1183-1242, r. 1224-1242) was the third shikken (regent) of the Kamakura shogunate in Japan. He strengthened the political system of the Hojo regency.
He was the eldest son of second shikken Yoshitoki. In 1218 be became the chief (betto) of the military office (samurai dokoro). In the Jokyu Incident of 1221, he led shogunate forces against the imperial court in Kyoto. After his victory, he remained in Kyoto and set up the Rokuhara Tandai. Yasutoki and his uncle Tokifusa became the first tandai.
When his father Yoshitoki and aunt Hojo Masako died, he succeeded shikken in 1224. He installed Hojo Tokifusa as the first rensho. In 1225 he set up Hyōjō (評定), the council system of the shogunate. In 1232 he promuglated Goseibai Shikimoku, the legal code of the shogunate. He has highly praised for his impartial justice.
He died in 1242. His grandson Tsunetoki succeeded shikken.