Nakagawa Jun'an (中川 淳庵, 1739 – 2 July 1786) was a Japanese medical doctor, botanist, and scholar of rangaku (Western learning).
He was a junior colleague of Sugita Genpaku, with whom he studied and worked in Obama Domain, Wakasa Province, a center for Western medicine in Edo period Japan.
Along with Sugita and Maeno Ryōtaku (前野 良沢), Nakagawa prepared Kaitai Shinsho, a translation of the Dutch "New Book of Anatomy."
Nakagawa grew up in the Kōjimachi area of Edo (modern-day Tokyo), and studied botany under Tamura Ransui (田村 藍水).
He met and studied with the Swedish botanist that same year in Edo, exploring the fields of natural history and learning how to take and analyze plant and mineral samples.