The Mercedes-Benz 300 SLR (W196s) was an iconic 2-seat sports racer that took sportscar racing by storm in 1955, winning that year's world sportscar championship before a catastrophic crash and fire at le mans ended its domination prematurely.

Designated "sl-r" (for sport leicht-rennen, eng: sport light-racing, later condensed to "slr"), the 3-liter thoroughbred was derived from the company's Mercedes-Benz W196 formula one racer. It shared most of its drivetrain and chassis, with the 196's fuel-injected 2,496.87 cc straight 8 bored and stroked to 2,981.70 cc and boosted to 310 bhp (230 kw).

The W196s monoposto driving position was modified to standard two-abreast seating, headlights were added, and a few other changes made to adapt a strictly track car to a 24-hour road/track sports racer.

Two of the nine 300 slr rolling chassis produced were converted into 300 slr/300 sl hybrids. Effectively road legal racers, they had coupé styling, gull-wing doors, and a footprint midway between the two models.