Billy Thorpe and the Aztecs were an Australian rock band formed in Sydney in 1963. They were active in two incarnations, the first as a beat band from 1963–1967, and as a hard rock band from 1968–1973. They emerged in 1964 with their cover of "Poison Ivy", which kept The Beatles from the top spot of the Sydney charts during the latter's Australian tour. They enjoyed further success through 1965 when the original members quit after a financial dispute.

After a brief solo career, Thorpe resurrected the Aztecs name in 1968 with a new line-up and a heavier rock direction influenced by guitarist Lobby Loyde. By the 1970s, the new Aztecs had become one of the most popular hard rock bands in the country with appearances at the Sunbury Pop Festival and hit songs such as "Most People I Know (Think That I'm Crazy)", before disbanding in 1973. Thorpe died from a heart attack in Sydney on 28 February 2007.