The Warnow (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 10 km 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 Rostock with the west bank of the river.
The Warnabi, a medieval Slavic tribe, probably derived their name from the Warnow.