The Rednitz (German pronunciation: [ˈʁeːdnɪts]) is a 46 km (29 mi) long river in Franconia, Germany, tributary of the Regnitz (more precisely: its southern, left headstream).

Slightly richer in water than the other source river Pegnitz and also richer in tributaries, it is hydrographically regarded as the upper reaches of the Regnitz, although the longest flow path in its system is approx.

The Rednitz flows north through Roth bei Nürnberg, Schwabach and the southwestern quarters of Nuremberg.

The Rednitz joins the Pegnitz to form the Regnitz in Fürth.

The river first appeared in written sources in the 8th century with the Latin name Radantia.