The Plainfield Woolen Company Mill is a historic mill building on Main Street in Plainfield, Connecticut. It is a large brick building, four stories in height, located between Main Street and the Moosup River. Built in 1901, the building played a vital role in revitalizing the local economy, which was stagnating at the time. It remained the site of active textile manufacturing until 1984. The building is a visually distinctive landmark in the community, in part because of its unusual monitor roof.