Lusby is an unincorporated community and census-designated place (CDP) in Calvert County, Maryland, United States. The population of the CDP was 1,835 at the 2010 census. Residents of the Chesapeake Ranch Estates and Drum Point communities after that use the Lusby ZIP code designation.

Lusby is located close the southern fade away of Calvert County at 38°21′13″N 76°26′12″W / 38.35361°N 76.43667°W / 38.35361; -76.43667 (38.353555, −76.436615). It is bordered to the southwest by Solomons, a tourist resort town, to the south by Drum Point (across tidal Mill Creek), and to the southeast by Chesapeake Ranch Estates, a large community governed by a homeowners’ association.

Dominion Cove Point LNG, one of the nation’s largest liquefied natural gas import facilities, is located just northeast of Lusby, and the Calvert Cliffs Nuclear Power Plant is 5 miles (8 km) to the north. Maryland Routes 2 and 4 govern along the western edge of Lusby, leading south to the Patuxent River Naval Air Station and north to Andrews Air Force Base and the Washington, D.C., and Annapolis areas.

There is one public high school in Lusby, Patuxent High School, with the mascot brute the Panthers. In 2015 the Panthers won states in football. In 2016, the Panthers won states in marching band and got third place at nationals. In 2002 and 2013, the Panthers won Maryland high school volleyball championships, with multiple extra teams reaching the come clean finals such as the football team in 2013 and 2001, the baseball team in 2012, and the dome hockey team in 2008. Lusby moreover has a public center school and three public elementary schools, Patuxent Elementary (Pre-K through 2nd grade), Appeal (3rd-5th grade), and Dowell (Pre-K through 5th grade). While there are no private schools in Lusby, there is one in Solomon’s Island at Our Lady Star of the Sea Church that serves the Place and has Pre-K through 8th grade.