Kokugakuin University (Japanese: 國學院大學), abbreviated as Kokugakudai (國學大) or Kokudai (國大), is a Shinto-affiliated private research university in Shibuya, Tokyo, Japan. The university consists of undergraduate departments in humanities and social sciences and a graduate school, and specializes in Japanese literature, history, and Shinto Studies.

The predecessor institution was founded in 1882 as an institution of classical and religious learning. Prince Arisugawa Takahito served as the institution's inaugural head.

In Japanese, the university uses kyūjitai characters to stylize its name. In government-published materials and several unaffiliated private publications, shinjitai characters are used instead to write as "国学院大学".