Count Ōtani Kōzui (大谷 光瑞, 27 December 1876 – 5 October 1948) was a Japanese Buddhist leader and explorer who was the 22nd Abbot of Nishi Hongan-ji and the head of the Honganji-ha sect of Buddhism.

Between 1902 and 1910, he financed three expeditions to Central Asia although his participation was stopped for his succession (see below).

In addition to his spiritual responsibilities and his Central Asian activities, Ōtani wrote about China, Manchuria and Chinese porcelain.

While playing the Great Game, British and Russian intelligence both suspected that his archaeological expeditions were little more than covers for espionage activities.

While he continued to sponsor the expeditions, he devoted himself to the modernization of the Jōdo Shinshū sect.