Oxford is a city in Butler County, Ohio, United States. The population was 23,035 at the 2020 census. A college town, Oxford was founded in 1810 to serve as the home of Miami University. The city lies in southwestern Ohio roughly 4 miles (6.4 km) from the Indiana–Ohio border, approximately 30 miles (48 km) northwest of Cincinnati and 35 miles (56 km) southwest of Dayton.