Marvin is a village in Union County, North Carolina, United States. The population was 5,579 at the 2010 census. It is a more rural suburb of Charlotte. According to the United States Census Bureau, the village has a total area of 3.9 square miles, of which 3.9 square miles is land and 0.04 square miles is water. Marvin is a border territory, which lies in the st…Marvin is a village in Union County, North Carolina, United States. The population was 5,579 at the 2010 census. It is a more rural suburb of Charlotte. According to the United States Census Bureau, the village has a total area of 3.9 square miles, of which 3.9 square miles is land and 0.04 square miles is water. Marvin is a border territory, which lies in the state of North Carolina but borders South Carolina to the southwest.