Flavius Zeno (; Greek: Ζήνων Zenon; c. 425 – 9 April 491) was Eastern Roman emperor from 474 to 475 and again from 476 to 491. Domestic revolts and religious dissension plagued his reign, which nevertheless succeeded to some extent in foreign issues. His reign saw the end of the Western Roman Empire following the deposition of Romulus Augustus and the death of Julius Nepos, but he was credited with contributing much to stabilising the Eastern Empire.

In ecclesiastical history, Zeno is associated with the Henotikon or "instrument of union", promulgated by him and signed by all the Eastern bishops, with the design of solving the monophysite controversy. The Henotikon was widely unpopular and eventually abandoned under Justin I.