Nakai Chikuzan (中井 竹山, 1730–1804) was a leading academic in the Kaitokudō academy tradition of scholarship.
An extrovert known for his bureaucratic skills and his firm precise kanji, Chikuzan was vastly different in demeanour to his brother Nakai Riken, although their underlying epistemologies, beliefs and degree of tenacious individualism were similar.
They both focused on the epistemological study of virtue in the merchant class of Tokugawa Japan, furthering the work of Goi Ranju and consolidating previous thought around the Kaitokudō school.
The first son of Nakai Shuan, one of the two main founders of the Kaitokudo, he was just as adept in the external bureaucratic maneuvering of administration as his father.
He attended the Kaitokudo from a young age, where his interests in the epistemological study of virtue were cultivated by the scholar Goi Ranju.