Biel/Bienne (official bilingual wording; German: [biːl]; French: [bjɛn]; Italian: Bienna, Romansh: Bienna, Latin: Belna) is a city in the district of theBiel/Bienne administrative district in the canton of Berne in Switzerland.

Biel/Bienne is on the language boundary between the French-speaking and German-speaking parts of Switzerland, and is throughout bilingual. Biel is the German name for the town, Bienne its French counterpart. The town is often referred to in both languages simultaneously. Since January 1, 2005, the official name has been "Biel/Bienne", unofficially also "Biel-Bienne". Until then, the city was officially named Biel (BE).

The city lies at the foot of the first mountain range of the Jura Mountains area, guarding the only practical connection to Jura in the area, on the northeastern shores of Lake Biel (Bielersee, Lac de Bienne), sharing the eastern tip of the lake with its sister city, Nidau, the administrative centre of theDistrict of Nidau. Neuchâtel, Solothurn, and Berne (the capital of Switzerland) lie west, east and southeast of Biel/Bienne. They all can be reached in about 30 minutes, either by train or by car.

The city has about 50,000 inhabitants and in 2000 the agglomeration had almost 89,000.