Biel/Bienne District is an administrative district in the Canton of Bern, Switzerland. It is located along both shores of the northeastern half of Lake Biel and is part of the Seeland administrative region, and its capital is Biel/Bienne. It contains 19 municipalities with an area of 97.63 km2 (37.70 sq mi) and a population of 90,536, over half of which lives in the district's capital. While it is the smallest district in surface area, it has the third largest population in the canton.

Biel/Bienne is a bilingual city in the canton of Bern in Switzerland. With over 55,000 residents, it is the country's tenth-largest city by population. The Biel urban area has a population of around 100,000 inhabitants. Biel/Bienne is the capital of the Biel/Bienne administrative district. The city has been an industrial and watchmaking heart of Switzerland since the 19th century. With world-famous watch brands such as Rolex, Omega and Swatch based in Biel/Bienne, the city is one of the main centres of the Swiss watch industry and is also referred to as the "world capital of watchmaking".