Oldenburg is an independent city in the district of Oldenburg in the state of Lower Saxony, Germany. The city is officially named Oldenburg (Oldb) (Oldenburg in Oldenburg) to distinguish from Oldenburg in Holstein.

During the French annexation (1811-1813) in the wake of the Napoleonic war against Britain, it was also known as Le Vieux-Bourg in French. The city is at the rivers Hunte and Haaren, in the northwestern region between the cities of Bremen in the east and Groningen (Netherlands) in the west. It has a population of 170,000 (November 2019). Oldenburg is part of the Bremen/Oldenburg Metropolitan Region, with 2.37 million people.

The city is the place of origin of the House of Oldenburg. Before the end of the German Empire (1918), it was the administrative centre and residence of the monarchs of Oldenburg.

Points of interest

• Core city centre, a large pedestrianized shopping destination for the region.
• Oldenburg State Theatre, oldest mainstream theatre in Oldenburg, first opened in 1833.
• Schloss Oldenburg in the city centre, until 1918 residence of the monarchic rulers of Oldenburg, today a museum. A public park, the Schlossgarten, is nearby.
• Weser-Ems Halle, exhibition and congress centre with outdoor fair area, located in Oldenburg Donnerschwee.
• Small EWE Arena and Large EWE Arena, two sports and event halls located near the main railway station, opened in 2005 and 2013, and seating up to 4,000 and 6,852 visitors respectively. The large arena is also home to the EWE Baskets Oldenburg basketball club