Putnam is a town in Windham County, Connecticut, United States. The population was 9,584 at the 2010 census. It is home to WINY, an AM radio station.
According to the United States Census Bureau, the town has a total area of 20.4 square miles (52.8 kmē), of which, 20.3 square miles (52.6 kmē) are land and 0.1 square mile (0.3 kmē) (0.54%) is water. The town is drained by the Quinebaug River, which runs north and south through the center of town. A tributary of the Quinebaug, the Five Mile River, runs north and south through East Putnam. Putnam has common boundaries with Thompson on the north (approx. 6 mi.), with Rhode Island on the east (approx. 2 mi.), with Killingly on the south (approx. 7 mi.) and with Pomfret and Woodstock on the west (approx. 4 mi.). The town is crossed by Interstate 395, U.S. Route 44, Connecticut Route 12, Connecticut Route 21 and Connecticut Route 171.
As of the 2010 census, there were 9,584 people, 3,950 households, and 2,396 families residing in the town. The population density was 472.1 people per square mile (182.2/kmē). There were 4,299 housing units at an average density of 211.8 per square mile (81.7/kmē).