Kan Shimozawa was a Japanese novelist and historical writer. He was born Umetani Matsutaro in Atsuta, Hokkaido on February 1, 1892. He was the half-brother of painter Migishi Kōtarō.

He graduated from the law school of Meiji University in 1914 and initially returned to his hometown where he worked for a lumber company. He moved back to Tokyo in 1918 to work for an electric company, and in 1919 joined the newspaper Yomiuri Shimbun as a reporter. He would move to the newspaper Tokyo Nichi Nichi Shimbun in 1926. While working as a reporter, he collected interviews with former Shinsengumi under the guidance of jurist Takeshi Osatake. These interviews served as the basis for the novel Shinsengumi Shimetsuki published in 1928 and adapted into a film in 1962. He would write two sequels, Shinsengumi Ibun (1929) and Shinsengumi Monogatari (1931), later collected together as the Shinsengumi Trilogy. His most famous character, the blind swordsman Zatoichi, first appeared in the 1948 essay "Zatoichi Monogatari" (座頭市物語), part of Shimozawa's "Futokoro Techō" serials in the magazine Shōsetsu to Yomimono. Originally a minor character, Zatoichi was dramatically altered by Daiei Film and actor Shintaro Katsu for the 1962 film The Tale of Zatoichi and further developed in 25 sequels to become one of Japan's longest-running film series. Shimozawa died of a heart attack on July 19, 1968 in Tokyo.