Lancaster
- Country: United States
- State: Ohio
- Population: 39,848 (2016)
- Latitude: 39° 42.8' N (39.71368°)
- Longitude: 82° 36' W (-82.59933°)
- Elevation: 268 m/879 ft. above sea level
- Time zone: America/New_York (UTC -05:00); DST observed (UTC -04:00)
- Alternate names: New Lancaster