Sterling is a town in Windham County, Connecticut, United States. The town is part of the Northeastern Connecticut Planning Region. The population was 3,578 at the 2020 census. The rural town is home to two villages: Oneco and Sterling village. Each contains a post office, a church, and a fire station. The town hall and public library are located in Oneco, and the town's one public school is in Sterling village.

Windham County is one of the eight historical counties in the U.S. state of Connecticut, located in its northeastern corner. As of the 2020 census, the population was 116,418, making it the least populous county in Connecticut. It forms the core of the region known as the Quiet Corner. Windham County is included in the Worcester, MA-CT Metropolitan Statistical Area, which is also included in the Boston-Worcester-Providence, MA-RI-NH-CT Combined Statistical Area. The entire county is within the Quinebaug and Shetucket Rivers Valley National Heritage Corridor, as designated by the National Park Service.