Rio Grande is an unincorporated community and census-designated place located within Middle Township and Lower Township in Cape May County, in the U.S. state of New Jersey. Though for the 1990 to 2010 U.S. censuses the CDP was entirely located within Middle Township, a small section at the southern edge of the community, located in Lower Township, is sometimes called Rio Grande. For the 2020 U.S. Census, the boundary was redrawn so that portions of Lower Township were included in the Rio Grande CDP. It is part of the Ocean City Metropolitan Statistical Area.