Whaam!, now considered one of Roy Lichtenstein's most important works, debuted at an exhibition held at the Leo Castelli Gallery, New York City.

Whaam! is a 1963 diptych painting by the American artist Roy Lichtenstein. It is one of the best-known works of pop art, and among Lichtenstein's most important paintings. Whaam! was first exhibited at the Leo Castelli Gallery in New York City in 1963, and purchased by the Tate Gallery, London, in 1966. It has been on permanent display at Tate Modern since 2006.

Roy Fox Lichtenstein was an American pop artist. He rose to prominence in the 1960s through pieces which were inspired by popular advertising and the comic book style. Much of his work explores the relationship between fine art, advertising, and consumerism.

Leo Castelli was an Italian-American art dealer who originated the contemporary art gallery system. His gallery showcased contemporary art for five decades. Among the movements which Castelli showed were Surrealism, abstract expressionism, Neo-Dada, pop art, op art, color field painting, hard-edge painting, lyrical abstraction, minimalism, conceptual art, and neo-expressionism.