Tadeusz "Tadek" Marek (1908–1982) was a Polish automobile engineer, known for his Aston Martin engines.
Marek was from Kraków and studied engineering at Technische Universität Berlin before working for Fiat in Poland and also for General Motors. Despite a serious racing accident in 1928, he raced the 1937 Monte Carlo Rally in a Fiat 1100 followed by a Lancia Aprilia in 1938 and an Opel Olympia in 1939. Driving a Chevrolet Master sedan, he won the XII Rally Poland (1939) before moving to Great Britain in 1940 to join the Polish Army. He joined the Centurion tank Meteor engine development (1944), but returned to Germany, working for United Nations Relief and Rehabilitation Administration.
In 1949 he joined the Austin Motor Company, and eventually joined Aston Martin (1954). He developed the alloy 6-cylinder engine (forerunner of the DB4 engine) of the Aston Martin DBR2 racing car (1956), and redesigned the Lagonda engine with a new cast iron block using top seating liners, used in the DB Mark III. The DBR2 engine (after changes) was subsequently used in the DB4, DB5, DB6 and DBS. Marek also developed the Aston Martin V8 engine (1968), which was in use until the year 2000. It was first fitted to a DB5 driven by Marek personally (1965), and two Aston Martin DB7 were also equipped with this V8 (1995).
Marek and his wife moved to Italy in 1968, and he died there in 1982.