Shi Nai'an (Chinese: 施耐庵; pinyin: Shī Nài'ān, ca. 1296—1372), was a Chinese writer from Suzhou. He was attributed as the first compiler of the Water Margin, one of the Four Great Classical Novels of Chinese literature.
Not much biographical information is known about him. Traditionally it was believed that he was a teacher of Luo Guanzhong, who was attributed as a main compiler of Romance of Three Kingdoms, another of the Four Great Classical Novels. Some modern scholars doubt that Shi actually existed, but was merely a pseudonym for Luo himself.