The Mercedes-Benz W111 was a chassis code given to a range of Mercedes-Benz vehicles produced between 1959 and 1971, including four-door saloons (1959–1968) and two-door coupés and cabriolets (1961–1971). Their bodywork featured distinctive tailfins that gave the models their Heckflosse nickname — German for "fintail".

The tailfin era of automobile styling encompassed the 1950s and 1960s, peaking between 1955 and 1961. It was a style that spread worldwide, as car designers picked up styling trends from the US automobile industry, where it was regarded as the "golden age" of American auto design and American exceptionalism.