Russell County is a county located in the Commonwealth of Virginia. As of the 2020 census, the population was 25,781. Its county seat is Lebanon. On January 2, 1786, Russell County was established from a section of Washington County. L.P. Summers, a Washington County historian later wrote, "Washington County lost a great extent of country and many v…Russell County is a county located in the Commonwealth of Virginia. As of the 2020 census, the population was 25,781. Its county seat is Lebanon. On January 2, 1786, Russell County was established from a section of Washington County. L.P. Summers, a Washington County historian later wrote, "Washington County lost a great extent of country and many valuable citizens when Russell County was formed." The county was named for Culpeper County native Colonel William Russell.