The Kaiserbrücke (English: Emperor Bridge), today officially the Nordbrücke (Northern Bridge), is a railway span on the Mainz rail bypass across the Rhine at the north end of Mainz in the state of Rhineland-Palatinate, Germany.

Built between 1901 and 1904, it was named for the German Emperor Wilhelm II, who officially opened it on 1 May 1904.

It formed an important part of the German railway system, as well as being an important logistical link for war transports (which were closely tied to railway infrastructure).

To forestall a second Remagen, the Germans by 19 March had blown all Rhine bridges from Ludwigshafen northward.

It was later reopened in 1955 as the Nordbrücke (Northern Bridge), with parts of the surviving foundations and sculptures adorning it incorporated into the new much less grand structure.