Zeno (c. 425 – 9 April 491), originally named Tarasis, is Byzantine Emperor from 474 to 475 and again from 476 to 491.

Domestic revolts and religious dissension plague his reign, which nevertheless succeeds to some extent in foreign issues.

His reign sees the end of the Western Roman Empire under Julius Nepos, but he contributes much to stabilizing 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.