The Tatra 603 is a large rear-engined luxury car which was produced by the Czechoslovak company Tatra from 1956 to 1975. It was a continuation of the series of Tatra streamlined sedans which began with the Tatra 77. In Socialist Czechoslovakia, only high-ranking party officials and heads of factories were driven in 603s; the car was also exported to a number of other countries.

Tatra is a Czech vehicle manufacturer from Kopřivnice. It is owned by the TATRA TRUCKS a.s. company, and it is the third oldest company in the world producing motor vehicles with an unbroken history. The company was founded in 1850 as Ignatz Schustala & Cie. In 1890 the company became a joint-stock company and was renamed the Nesselsdorfer Wagenbau-Fabriksgesellschaft. In 1897, the Nesselsdorfer Wagenbau-Fabriksgesellschaft produced the Präsident, which was the first factory-produced automobile with a petrol engine to be made in Central and Eastern Europe. In 1918, the company was renamed Kopřivnická vozovka a.s., and in 1919 it changed from the Nesselsdorfer marque to the Tatra badge, named after the nearby Tatra Mountains on the Czechoslovak-Polish border.