Xi Zezong (June 6, 1927, Yuanqu, Shanxi – December 27, 2008, Beijing) was a Chinese astronomer, historian, and translator.
He is best known for finding in ancient Chinese history a reference to Ganymede being visible to the human eye by ancient astronomer Gan De, before it was officially recognised by the West.
He was a member of the Chinese Academy of Sciences, and an Awardee of the Astronomy Prize.