Maskin was born in New York City, New York on December 12, 1950, to a non-religious Jewish family, and grew up in Alpine, New Jersey. He graduated from Tenafly High School in Tenafly, New Jersey in 1968, and then studied at Harvard University where he received his A.B. and Ph.D. After he got his Ph.D., Maskin went to the University of Cambridge in 1976 where he was a research fellow at Cambridge College. He taught at Massachusetts Institute of Technology from 1977-1984 and from 1985-2000 at Harvard, where he was the Louis Berkman Professor of Economics. In 2000, he moved to the Institute for Advanced Study in Princeton, New Jersey.