Montchanin is an unincorporated community in New Castle County, Delaware, United States. The community was named for Anne Alexandrine de Montchanin, mother of Pierre Samuel du Pont de Nemours. The Jacob Broom House, a National Historic Landmark, is located there. The Jacob Broom House, Montchanin Historic District, and Strand Millas and Rock Spring are listed on the National Register of Historic Places.