Coinjock is an unincorporated community and census-designated place (CDP) in Currituck County, North Carolina, United States. As of the 2010 census it had a population of 335. It is located on U.S. Route 158 between Barco and Grandy, about south of the Virginia state line, and is at mile marker 50 on the Intracoastal Waterway. Church's Island to the east of Coinjock in the Currituck Sound has a village called Waterlily, which uses the postal address of Coinjock as well. The island's name is due to a decayed church that was once a landmark of the tiny community. Coinjock is bordered by Currituck Sound to the east; the North River lies to the west. Its ZIP code is 27923.
Residents suggest the name Coinjock is of Native American origin referring to mulberries, which might have been prevalent in the area many years ago. There are no mulberry trees there now. The name has also been spelled "Coenjock", "Cowenjock", or "Cornjack", and sometimes as two words with the second beginning with a capital J. Bishop Thomas Coke visited Coenjock, as he called it, and preached to a small congregation in its chapel on March 19, 1785.