The Lancia Delta S4 is a Group B rally car manufactured by the Italian car company Lancia. The Delta S4 competed in the World Rally Championship in 1985 and 1986, until Group B class was disbanded and the cars were eventually banned from competition completely by European sanctioning body FIA. While sharing the same name and appearance, the S4 variant was a race car designed and built specifically for rallying, and was entirely different from the mass-produced consumer versions of the first generation Delta. The S4 'Stradale' was the road-going version built for homologation requirements.