Byram is a neighborhood/section and census-designated place in the town of Greenwich in Fairfield County, Connecticut, United States. It had a population of 4,146 at the 2010 census, and a census-estimated population of 4,216 in 2018. An endcap of Connecticut's Gold Coast, Byram is the southernmost point in the town of Greenwich and the U.S. state of Connecticut. It is separated from Port Chester, Westchester County, New York, by the Byram River. Byram was once known as East Port Chester.