The Warnow (German pronunciation: [ˈvaʁno]) is a river in the state of Mecklenburg-Vorpommern in Germany. It flows into the Baltic Sea near the town of Rostock, in its borough Warnemünde.
The source of the Warnow is in Grebbin, a small village 10 kilometres (6 mi) north of Parchim, at the western end of the Mecklenburg Lake District. It flows north through Sternberg, Bützow and Schwaan before reaching Rostock.
In 2003, Germany's first modern toll road, the Warnow Tunnel was opened, connecting the port of Rostock on the east bank with the west bank of the river.
The Warnabi, a medieval Slavic tribe, probably derived their name from the Warnow.