Ledyard (lĕdˈyərd) [key], town (1990 pop. 14,913), New London co., SE Conn., on the Thames River; settled c.1653, inc. 1836. It is a farm center. The site of Fort Decatur is marked there. A gambling casino and hotel complex, opened in 1992 on the nearby Mashantucket Pequot reservation, has greatly enhanced the regional economy, including that of Ledyard. A comprehensive tribal museum is also there.