The Wild Weißeritz (German: Wilde Weißeritz, Czech: Divoká Bystřice) is a river in the Czech Republic and in the German state of Saxony which drains the eastern Ore Mountains. It is the longest tributary of the Weißeritz.
The valley of the Wild Weißeritz is almost free of settlements. The Wild Weißeritz runs through Tharandt just some kilometres before it forms the Weißeritz together with the tributary Red Weißeritz in Freital.