Evsey David Domar (Russian: Евсей Давидович Домашевицкий, Domashevitsky; April 16, 1914 – April 1, 1997) was a Russian-American economist, famous as developer of the Harrod–Domar model.

Evsey Domar was born on April 16, 1914, in the Polish city of Łódź, which was part of the Russian Empire at that time. He grew up in Manchuria, living in Dairen and Harbin where he attended the State Faculty of Law studying economics, before emigrating to the United States in 1936.

He received a Bachelor of Arts from UCLA in 1939, a Master of Science from the University of Michigan in 1940, a Master of Science from Harvard University in 1943, and a doctorate from Harvard in 1947.

In 1946 Evsey Domar married Carola Rosenthal. The couple had two daughters.

He was a professor at the Carnegie Institute of Technology, The University of Chicago, the Johns Hopkins University and then at the Massachusetts Institute of Technology from 1957 until the end of his career.

Evsey Domar was president of the Association for Comparative Economics and a member of several other academic organizations including the American Academy of Arts and Sciences, the Econometric Society, and the Center for Advanced Study in the Behavioral Sciences. He was on the executive committee of the American Economic Association from 1962 until 1965, and became the organization's vice president in 1970. In 1965, he was the first recipient of the John R. Commons Award, given by the economics honor society Omicron Delta Epsilon.

He worked for the RAND Corporation, the Ford Foundation, the Brookings Institution, the National Science Foundation, the Battelle Memorial Institute, and the Institute for Defense Analysis.

Evsey Domar died on April 1, 1997, in the Emerson Hospital in Concord, Massachusetts 15 days before his 83rd birthday.