| Wester | |
| Mouth Location: | Möhne |
| Mouth Coordinates: | 51.4889°N 8.3331°W |
| Subdivision Type1: | Country |
| Subdivision Type2: | State |
| Length: | 14.3km (08.9miles) |
| Tributaries Right: | Langer Bach, Treise |
Wester (in its upper course: Wideybach) is a 14-km long river, a southern tributary of Möhne of North Rhine-Westphalia, Germany. It flows between the Warstein and Belecke subdivisions (German: ortsteil) of the town of Warstein.