Killingly is a town in Windham County, Connecticut, United States. The population was 17,370 at the 2010 census. It consists of the borough of Danielson and the villages of Attawaugan, Ballouville, Dayville, East Killingly, Rogers, and South Killingly.
Danielson Airport is a state owned, public use airport located two nautical miles (4 km) northwest of the central business district of Danielson, a borough in Killingly.
As of the census of 2010, there were 17,370 people, 6,749 households, and 4,528 families residing in the town. The population density was 358.1 people per square mile (137.9/kmē). There were 7,592 housing units at an average density of 156.5 per square mile (60.3/kmē).