Higganum, a census-designated place (CDP) in the town of Haddam, a part of Middlesex County, Connecticut, United States. The population was 1,671 at the 2000 census. At about 1800, Higganum Village was the center of most economic activity in the town. The neighborhood had abundant water power, and Higganum Landing was a natural cove and river port. Higganum now encompasses the town's traditional village center and remains the shopping and civic center for Haddam.