The Brunnenbach is a 12 km (7.5 mi) long, right-hand tributary of the Warme Bode, which flows to the west and south of Braunlage in Goslar district in the north German state of Lower Saxony.

Shortly after its source the Brunnenbach is impounded by the Silberteich reservoir, before it continues in a southeasterly direction past the Mutter-Kind-Heim Waldmühle, a mother-and-child centre, and local campsite. It then passes the forest inn of Forellenteich and the forest youth centre of Brunnenbachsmühle [de], before finally turning east. The Brunnenbach is one of the most important tributaries of the Warme Bode.

• Fußstiegbach (left)
• Großer Kronenbach (right)
• Schächerbach (right)
• Blechhüttenbach (left)

• List of rivers of Lower Saxony