Böse Sieben (German for "evil seven") is a river of Saxony-Anhalt, Germany, flowing through the town Eisleben.

The Böse Sieben originates from the eastern regions of the Harz, the sources of the river are the Vietzbach (or Goldbach) and the Dippelsbach, which confluence in Ahlsdorf.

The Böse Sieben is fed by two sources, the streams Vietzbach, known also as Goldbach, and Dipplesbach, which unite in Ahlsdorf.

Other tributaries include the Kleibigbach, Goldgrundbach, Pfaffengrundbach, Saugrundbach and Wolfroder Bach.

Since these can swell rapidly during rains, and cause rampant floods across the Mansfeld region, the explanation for the name may be found here.