The Aubach is an orographically left tributary of the River Wiehl in the German state of North Rhine-Westphalia.

[1] The Aubach rises north of Wendershagen, at the Heckenweiher, approximately 414 metres (1,358 ft) above sea level.

It rises in Wildberg to about 382 metres (1,253 ft) m above sea level, and is additionally fed by the roughly 1.2 kilometres (0.75 mi) long Langenbach.

The upper course of the Aubach valley is characterised by dense, shady forests, under which only a sparse layer of herbs flourishes.

Wild herbaceous plants can also be found on the banks of the Aubach River, such as Anemone sylvestris or Ficaria verna.