The Dosse is a river in the district of Ostprignitz-Ruppin in the northwestern part of Brandenburg, Germany. It is a right tributary of the Havel in Saxony-Anhalt. The Dosse is 94 km long, with its source on the border between Mecklenburg-Vorpommern and Brandenburg, arising out of three small brooks that unite after four kilometres. It flows generally south, through Wittstock, Wusterhausen, and Neustadt an der Dosse, before joining the Havel near Havelberg in Saxony-Anhalt. The total catchment area is 1268 km2. With the town of Wittstock on its banks, the Dosse was the site of the 1636 Battle of Wittstock between Sweden and an alliance between Imperial and Saxon troops during the Thirty Years' War.