Putnam County is a county located in the U.S. state of New York. As of the 2020 census, the population was 97,668. The county seat is Carmel. Putnam County was formed in 1812 from Dutchess County and is named for Israel Putnam, a hero in the French and Indian War and a general in the American Revolutionary War. Putnam County is included in the New York–Newark–Jersey City, NY–NJ–PA Metropolitan Statistical Area. It is located in the lower Hudson River Valley.