| Mūša, Mūsa | |
| Mouth Coordinates: | 56.4028°N 24.1594°W |
| Subdivision Type1: | Country |
| Length: | 164km (102miles) |
| Basin Size: | 5318km2 |
| Tributaries Right: | Kruoja, Lėvuo, Pyvesa, Tatula |
The Mūša (Latvian: Mūsa; German: Muhsse) is a river in Northern Lithuania and Southern Latvia (Zemgale region). At its confluence with the river Nemunėlis (Latvian: Mēmele) in Latvia, near the city of Bauska, the river Lielupė is formed. The river is 164 kilometers (146 km in Lithuania, 18 km in Latvia) long.