Windham County is a county located in the northeastern corner of the U.S. state of Connecticut. As of 2000, the population was 109,091. The entire county is within the Quinebaug and Shetucket Rivers Valley National Heritage Corridor, as designated by the National Park Service.

Major highways through Windham County include Interstate 395, which runs north-south from the New London County line at Plainfield to the Massachusetts state line at Thompson. The southern part of I-395 is part of the Connecticut Turnpike, which branches off the interstate in Killingly and runs east-west from I-395 exit 90, to US Route 6 at the Rhode Island state line. Other north-south routes include State Route 12, which parallels I-395 through many local communities, State Route 169, a National Scenic Byway traveling through rural communites from the New