Orange County is a county located in the Central Piedmont region of the Commonwealth of Virginia. At the 2020 census, the population was 36,254. Its county seat is Orange. Orange County includes Montpelier, the 2,700-acre estate of James Madison, the 4th President of the United States and often known as the "Father of the Constitution". The count…Orange County is a county located in the Central Piedmont region of the Commonwealth of Virginia. At the 2020 census, the population was 36,254. Its county seat is Orange. Orange County includes Montpelier, the 2,700-acre estate of James Madison, the 4th President of the United States and often known as the "Father of the Constitution". The county will celebrate its 290th anniversary in 2024.