NSU-Fiat was a German automobile manufacturer which produced Fiat vehicles under license at a plant acquired from NSU in Heilbronn from 1929 to 1957.

In 1957, following a complicated litigation process over the right to use the by now increasingly high profile "NSU" name on passenger cars, the name used for the Fiat-designed cars was changed to Neckar, and with this name the company continued to produce Fiats in Germany until 1971.

NSU Motorenwerke (subsequently NSU Werke) AG sold its then recently completed Heilbronn car factory (near the river Neckar) in 1929 to Fiat for one Million Marks, following financial problems resulting from the economic crisis. The deal resulted from an initiative by NSU's bankers, Dresdner Bank.