Billy Apple was born in Auckland, New Zealand, as Barrie Bates. He studied at the Royal College of Art in London from 1959 to 1962, and changed his name to Billy Apple in 1962. In 1964 Apple moved to New York, where his work was included in the seminal exhibition The American Supermarket, a show held in Paul Bianchini's gallery. The show was presented as a typical small supermarket environment, except that everything in it was created by six prominent pop artists of the time, including Billy Apple, Andy Warhol, Claes Oldenburg, Tom Wesselmann, Jasper Johns, Mary Inman, James Rosenquist and Robert Watts. In 1974 Apple's first major survey exhibition was held at the Serpentine Gallery in London: From Barrie Bates to Billy Apple. In 1975 Apple returned to New Zealand where he embarked on a national exhibition tour with support from the Queen Elizabeth II Arts Council of New Zealand.
His practice has a close relationship to advertising, branding, and technology while simultaneously reflecting a political agenda. The image of the apple has become a reoccuring motif in his work, and has been reproduced in both sculptural and printed works. Through collaboration with Andy Warhol, his work has been associated with Pop Art, as well as Conceptual Art.