Mount Harmon is an historic home, located at Earleville, Cecil County, Maryland, United States.

The Mount Harmon Plantation estate and nature preserve covers some 200-acre (0.81 km2) adjacent to the Chesapeake Bay, on a peninsula by the north shore of the Sassafras River.

In 1963, Marguerite duPont de Villiers Boden, a direct descendant of the Louttits and Georges, rescued the plantation, restoring the Colonial Kitchen and Manor House.

After Mrs. Boden's death, her daughter Kip Kelso Boden Crist ensured the plantation's future by forming Friends of Mount Harmon, Inc. Today, the Friends of Mount Harmon (FOMH), almost all volunteers, preserve and interpret the plantation for the education and enjoyment of its visitors.

[further explanation needed] The formal boxwood garden is used for weddings, and the spacious Manor House grounds are open for festive events and corporate meetings.