Bielefeld (German pronunciation: [ˈbiːləfɛlt]) is a county borough in the Regierungsbezirk (regional district) Detmold in the north-east of North Rhine-Westphalia, Germany. It is located at [show location on an interactive map] 52°01′00″N 08°31′00″E / 52.016667°N 8.516667°E / 52.016667; 8.516667 on both the western and eastern slopes of the Teutoburg Forest. With its population of 326,000, it is the biggest city of the Ostwestfalen-Lippe Region. The current mayor is Eberhard David.
The name Bielefeld is derived from the old name bileveld, which means "hilly field". The city is situated below a pass separating the Northern and Southern Teutoburg Forest. The centre of Bielefeld is situated on the eastern side of the Teutoburg Forest, but the modern city incorporates boroughs on the opposite side and on the hilltops.