The Audi 80 is a compact executive car produced by the Audi subdivision of the Volkswagen Group across four generations from 1966 to 1996. It shared its platform with the Volkswagen Passat from 1973 to 1986 and was available as a saloon, and station wagon — the latter marketed by Audi as the Avant. The coupé and convertible models were not badged as members of the range but used a derivative of the same platforms.

In North America and Australia, the 80 was marketed as the Audi Fox for model years 1973–79, and as the Audi 4000 for model years 1980–87 in the US. The Audi 90 was an upmarket version of the Audi 80, although all North American sedans of the B4 generation were called Audi 90.