john geanakoplos was born to a greek-american family of scholars. his father was the late professor emeritus at yale deno geanakoplos (), a renowned greek-american historian of byzantine cultural and religious history, and his mother, effie geanakoplos, was an instructor in psychiatry at the yale child study center. in 1970 geanakoplos won the united states junior open chess championship. he received his b.a. in mathematics from yale university in 1975 (summa cum laude), and his m.a. in mathematics and his ph.d. in economics under kenneth arrow and jerry green from harvard university in 1980. in 1980 he became an assistant professor of economics at yale university, rising to associate professor in 1983, full professor in 1986, and the james tobin professor of economics in 1994.