The S was the first performance model developed under Mercedes-Benz following the merger of Benz & Cie. and DMG in 1926. Designed by Ferdinand Porsche after the 6.3-liter Model K, itself a replacement for the aging 28/95 HP, the S was well regarded for its performance, acting as both a stylish touring car and highly successful racer. With its polished radiator, raked windshield, and dramatic hood that stretched half the body length, the S visually embodied the elegance and abandon of the Roaring Twenties. Elements of its design would later be imitated by manufacturers around the world, including American automakers such as Duesenberg.

Sindelfingen, the in-house coachbuilder for Mercedes-Benz, offered numerous body styles for the S, each of which could be customized to the owner’s specification. The signature style of Sindelfingen coachwork emphasized the car's mechanical presence with purposeful lines that borrowed from the streamlined shapes of the era. A distinctive hoodline crease running the length of the car drew attention to its length and low profile. Fenders, while restrained, imparted a sense of effortless speed.

The S refined the design of the Model K, reducing the former’s weight by over 500 pounds and featuring lower bodywork and a more powerful engine. It was notably more powerful than any car sold in America at the time.