Bielefeld is a city in the Ostwestfalen-Lippe Region in the north-east of North-Rhine Westphalia, Germany. With a population of 327,000, it is also the most populous city in the Regierungsbezirk Detmold.

The historical centre of the city is situated north of the Teutoburg Forest line of hills, but modern Bielefeld also incorporates boroughs on the opposite side and on the hills. Bielefeld is home to a significant number of internationally operating companies, including Dr. Oetker, Gildemeister and Schüco. It has a university and several Fachhochschulen. Bielefeld is also famous among Germans for its internet meme, the Bielefeld Verschwörung.