Willimantic is a census-designated place and former city located in the town of Windham in Windham County, Connecticut, United States. The population was at 17,737 at the 2010 census. It is home to Eastern Connecticut State University, as well as the Windham Textile and History Museum. The city was incorporated in 1893 as a section of the town of Windham. The city government was dissolved in 1983 with the area reverting back to the town. It is also the birthplace of U.