Jacksonville is a city in Jackson County, Oregon, United States, approximately 5 miles west of Medford. It was named for Jackson Creek, which flows through the community and was the site of one of the first placer gold claims in the area. It includes Jacksonville Historic District, which was designated a U.S. National Historic Landmark in 1966. As of the 2010 census, the city population was 2,785, up from 2,235 at the 2000 census.