Keedysville is a town in Washington County, Maryland, United States. The population was 1,152 at the 2010 census.
The first documented house in Keedysville was built in 1738. The description for George Gordon's "Gordon's Purchase" land tract notes "...one log house, 12 x 15 feet..." The initial warrant for the tract had been issued to Owen McDonald in Jan. 1738, the year before Gordon acquired it. Gordon's Purchase was the first tract taken up by a Euromerican within what would eventually become Keedysville. The main road at that time was the Conococheague Road, which branched from the Great Wagon Road just east of Keedysville and led to the farthest reaches of the provence, passing through what would eventually be Keedysville. The house and its exact location are unknown but the starting point for Gordon's Purchase was on today's Bell Lane. As more settlers moved into the region a grist mill was built on Little Antietam Creek about 1765 to serve the earliest farmers who were mostly German and Swiss immigrants who'd migrated from Pennsylvania. This mill was bought by Jacob Hess in 1770.