The Mercedes-Benz 300SL (W198) was the first iteration of the SL-Class grand tourer and fastest production car of its day. Introduced in 1954 as a two-seat coupé with distinctive gull-wing doors, it was later offered as an open roadster. Built by Daimler-Benz AG, the direct fuel injected production model was based on the company's highly successful yet somewhat less powerful carbureted overhead cam straight 61952 racer, the W194.

The idea of a toned-down Gran Prix car tailored to affluent performance enthusiasts in the booming post-war American market was suggested by Max Hoffman. Mercedes accepted the gamble and the new 300 SL – 300 for its 3.0 litre engine displacement and SL for Sport Leicht (Sport Light) – was introduced at the 1954 New York Auto Show rather than the Frankfurt or Geneva gatherings company models made their usual debuts.

Immediately successful and today iconic, the 300SL stood alone with its distinctive doors, first-ever production fuel-injection, and world's fastest top speed. The original coupé was available from March 1955 to 1957, the roadster from 1957 to 1963.

A notably smaller, lighter, and less luxurious 1.9 liter roadster was introduced in 1955 as the 190SL. Both the 300SL and the 190SL were followed in the Mercedes line by the230SL. Today's 571 hp (426 kW), nearly 200 mph (320 km/h), gull-winged Mercedes-Benz SLS AMG is regarded as the 300SL's spiritual successor.