Gwinnett County is a county in the north central portion of the U.S. state of Georgia. As of the 2010 census, the population was 859,304, making it the second-most populous county in Georgia. Its county seat is Lawrenceville. The county is named for Button Gwinnett, one of the signers of the Declaration of Independence. Gwinnett County is included in the Atlanta-Sandy Springs-Roswell, GA Metropolitan Statistical Area.