Luo Guanzhong, also known by his courtesy name Guanzhong and his pseudonym Huhai Sanren (Chinese: 湖海散人; pinyin: Húhǎi Sǎnrén; literally "Leisure Man of Lakes and Seas"), was a prominent Chinese novelist who lived during the Ming dynasty.

He is best known for writing Romance of the Three Kingdoms, one of the Four Great Classical Novels of Chinese literature. He is also believed to have assisted Shi Nai'an (if the latter existed and wasn't just one of Luo's pseudonyms) in writing Water Margin.