Ki no Arimasa (紀在昌)

KI no Arimasa (year of birth and death unknown) was a low to middle rank government official and Confusion scholar during the mid-Heian period. He was a grandson of the Chunagon (vice-councilor of state) KI no Haseo. His father was KI no淑信. Among his children were KI no Koresuke, KI no Koreto, KI no 伊賢, and KI no Kanesuke.

After passing the Taisaku (an examination for adopting government officials under the Ritsuryo legal codes), Arimasa consecutively worked in different positions, including Naiki (Secretary of the Ministry of Central Affairs) and Monjo hakase (professor of literature), later reaching the rank of Jushiinojo (Junior Fourth Rank, Upper Grade) with a post in the Shikibu-sho (the Ministry of Ceremonial). He was active during the eras of Emperor Daigo and Emperor Murakami, and served as Jidoku (imperial tutor) for Imperial Prince Norihira (Emperor Reizei).

Chinese poetry and kanbun (Chinese classics) written by Arimasa are in "Monzui" and "Ruijin kudaisho" (anthology of Chinese poetry).