Greenville County is located in the U.S. state of South Carolina. As of the 2020 census, the population was 525,534, making it the most populous county in the state. Its county seat is Greenville. The county is also home to the Greenville County School District, the largest school system in South Carolina.

Interstate 85 (I-85) in the U.S. state of South Carolina runs northeast–southwest through Upstate South Carolina. Connecting regionally with Atlanta, Georgia, and Charlotte, North Carolina, it became the first Interstate Highway in South Carolina to have its originally planned mileage completed.