The William Jillson Stone House is a historic house museum at 561 Main Street in the Willimantic section of Windham, Connecticut. It is a two story structure, built of native granite laid in alternating wide and narrow courses. The house is locally significant as a rare example of a stone house, and as the home of William Jillson, a native of Cumberland, Rhode Island, who was one of the first people to purchase industrial water rights at the Willimantic Falls. It is now owned by the Windham Historical Society.