Byram is a neighborhood/section and census-designated place (CDP) in the town of Greenwich in Fairfield County, Connecticut, United States.

It is separated from Port Chester, Westchester County, New York, by the Byram River.

Of these neighborhoods, three (Cos Cob, Old Greenwich, and Riverside) have separate postal names and ZIP codes.

Byram Quarry, now closed, supplied stone for the Brooklyn Bridge, the base of the Statue of Liberty and St. Roch Church.

A scene from the movie The Good Shepherd was shot in Byram.