Broomes Island is a small waterfront community and census-designated place (CDP) located at the southern terminus of MD 264 in Calvert County, Maryland, United States, on the Patuxent River. It is located approximately 10 miles (16 km) south of Prince Frederick, the county seat. As of 2019 Census estimates, the population of the CDP was 421. Broomes Island is located near the mouth of St. Leonard Creek, the largest tributary of the Patuxent River entirely inside Calvert County. It is in the vicinity of Broomes Island that several key naval battles were fought during the War of 1812.