East Brooklyn is a census-designated place located within the town of Brooklyn in Windham County, Connecticut, United States. It is the portion of the Danielson urban cluster within the town of Brooklyn. The population was 2,205 at the 2020 census. US 6 runs through the town and severs the town. The portion of the CDP near the Quinebaug River is known as the Quinebaug Mill-Quebec Square Historic District.