Hà Âjà  Yasutoki (; 1183 â July 14, 1242) was the third shikken (regent) of the Kamakura shogunate in Japan. He strengthened the political system of the Hà Âjà  regency.
He was the eldest son of second shikken Hà Âjà  Yoshitoki. According to Azuma Kagami, he was liked by the first shà Âgun, Minamoto no Yoritomo. In 1218, he became the chief (bettà Â) of the Board of Retainers (samurai-dokoro).
In the Jà Âkyà « War 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 Hà Âjà  Masako died, he succeeded to become shikken in 1224. He installed Hà Âjà  Tokifusa as the first rensho. In 1225 he created the Hyà Âjà  (), the council system of the shogunate. In 1232 he promulgated the Goseibai Shikimoku, the legal code of the shogunate. He was highly praised for his impartial justice.
In 1242, he was ordained as a Buddhist monk and took the Dharma name Jà Âshà Âbà  Kan'a (ä¸ÂèÂÂæ¿観é¿).
He died in the same year. His grandson Tsunetoki succeeded him to the post of shikken.