[2] Prior to the arrival of Europeans, the region was occupied by Algonquian peoples, including the Pequot, Mohegan, Narragansett, and Nipmuck.

After the conclusion of the Pequot War in 1638, the Pequots ceased to exist as a tribe; after King Philip's War ended in 1678, the Narragansett and Nipmuck did as well, leaving the Mohegans the only native power in the region.

The tract was named the town of Windham in May 1692, and was incorporated into Hartford County in fall of 1693.

[4]: 82-83 Starting in the early nineteenth century, the town's center of activity moved from Windham to Willimantic, as the water power available there led to the establishment of factories.

[4]: 104  First established as a borough in 1833,[5] it was incorporated as a separate city in 1893, then reincorporated into the town of Windham in 1983 as its industry declined.

29.8% of all households were made up of individuals, and 11.2% had someone living alone who was 65 years of age or older.

[11] The alternative high school, Windham Phoenix Academy, is designed to provide individualized instruction and offers a transition program for 18-22 year olds (Assisted Work Program).

[11] In Willimantic, a public STEM-focused magnet school, Charles Barrows, enrolls students in kindergarten through eighth grade through a lottery system.

Windham Tech students come from twenty-three different towns as of the 2023-24 school year.

[14] A Catholic school for students in grades pre-K through 8, St. Mary-St. Joseph, is also located in downtown Willimantic.

[15][16] Public Schools located in the town of Windham: Private Schools located in the town of Windham: Eastern Connecticut State University, a four-year liberal arts college, is located in Willimantic, as is a satellite campus of Quinebaug Valley Community College.