The Hayashi clan was a Japanese samurai clan which served as important advisors to the Tokugawa shōguns. Among members of the clan in powerful positions in the shogunate was its founder Hayashi Razan, who passed on his post as hereditary rector of the neo-Confucianist Shōhei-kō school to his son, Hayashi Gahō, who also passed it on to his son, Hayashi Hōkō; this line of descent continued until the end of Hayashi Gakusai's tenure in 1867. However, elements of the school carried on until 1888, when it was folded into the newly organized Tokyo University.

Hayashi Razan , also known as Hayashi Dōshun, was a Japanese historian, philosopher, political consultant, and writer, serving as a tutor and an advisor to the first four shōguns of the Tokugawa bakufu. He is also attributed with first listing the Three Views of Japan. Razan was the founder of the Hayashi clan of Confucian scholars.