Yisrael Robert John Aumann  (born June 8, 1930) is an Israeli mathematician and a member of the United States National Academy of Sciences. He is a professor at the Center for the Study of Rationality in the Hebrew University of Jerusalem in Israel. He also holds a visiting position at State University of New York, Stony Brook and is one of the founding members of the Center for Game Theory in Economics at Stony Brook.

Aumann was awarded the 2005 Nobel Memorial Prize in Economics for "having enhanced our understanding of conflict and cooperation through game-theory analysis". He shared the prize with Thomas Schelling.