Petersburg is an independent city in the U.S. state of Virginia. As of the 2020 census, the population was 33,458. The Bureau of Economic Analysis combines Petersburg with Dinwiddie County for statistical purposes. The city is 21 miles (34 km) south of the commonwealth (state) capital city of Richmond. It sits at the fall line of the Appomattox River, a tributary of the longer, larger James River which flows east to meet the southern mouth of the Chesapeake Bay at the Hampton Roads harbor and the Atlantic Ocean.