Prussia may refer to several related areas:
- A land on the southeastern coast of the Baltic Sea.
- The Kingdom of Prussia, ruled from 1701 by the German Hohenzollern dynasty, at first including Prussia and Brandenburg, a principality with Berlin as its capital. Initially a part of the Holy Roman Empire, Prussia gradually expanded in size, eventually becoming the dominant part of the German Empire, with the Prussian King also being the German Emperor.
- A division of the Weimar Republic.