- a city in NW Switzerland, on the Aar River: capital of canton of Solothurn.
- a canton in NW Switzerland.
- a canton of NW Switzerland. Capital: Solothurn. Pop: 246 500 (2002 est). Area: 793 sq km (306 sq miles)
- a town in NW Switzerland, capital of Solothurn canton, on the Aare River. Pop: 15 489 (2000)
