Sōshō 宗性 (1202–1278) was a Kamakura-period Japanese Kegon 華嚴 (Huayan) scholastic of Tōdai-ji 東大寺 in Nara. The dominant Tōdai-ji scholar of the mid-thirteenth century and one of the most prolific manuscript-compilers in Japanese Buddhist history, he was head (学頭, gakutō) of the Sonshō-in 尊勝院, lecturer (講師) at the Yuima-e 維摩會, and — at the recommendation of the retired Emperor Go-Saga 後嵯峨 — bettō (別當, chief abbot) of Tōdai-ji. DILA Authority A000577. Wikidata Q3511699.
His surviving corpus runs to many tens of fascicles of holograph and autograph manuscripts preserved at Tōdai-ji and the Sonshō-in, including the Kanripo entry Jùshě Lùn Běnyì Chāo 倶舍論本義抄 (KR6l0024, T2249) — the largest Japanese scholastic treatment of Vasubandhu’s Abhidharmakośa and of Xuanzang’s Chinese translation; he is also known for an encyclopedic Sōshō shōnin shutsuyō shū 宗性上人出要集 and a substantial body of devotional writings, including a Tushita-Maitreya manual. His principal disciple was Gyōnen 凝然 (凝然, 1240–1321), the celebrated author of the Hasshū kōyō 八宗綱要.
Standard biographical study: Hiraoka Jōkai 平岡定海, Tōdaiji Sōshō shōnin no kenkyū narabini shiryō (Tōkyō, 1958–1960).