Wolfenbüttel is a town in Lower Saxony, Germany. It is located on the Oker river, just a few kilometres south of Braunschweig (Brunswick) and east of Salzgitter, in the district of Wolfenbüttel. Population: 53,600.

It is unknown when Wolfenbüttel was founded, but it was first mentioned in 1118. Probably the first settlement was restricted to a tiny islet in the Oker river. Wolfenbüttel became a residence for the dukes of Brunswick in 1432. In the following three centuries the town was a centre of the arts. Michael Praetorius, Gottfried Leibniz and Gotthold Ephraim Lessing were residents of Wolfenbüttel. In 1753 the court moved to the city of Brunswick and the town lost its importance. Today it is smaller than the neighbouring cities of Brunswick, Salzgitter and Wolfsburg, but it still retains its ancient character.

The library of Wolfenbüttel (Herzog-August-Bibliothek) is one of the best known collections of ancient books in the world. It was founded in 1572; the library building was constructed in 1886. Leibniz and Lessing themselves worked in this library.