Morley was born in north London. He had a troubled childhood, and did not discover art until serving a three-year stint in Wormwood Scrubs prison. After release, he studied art first at the Camberwell School of Arts and then at the Royal College of Art (1955-1957), where his fellow students included Peter Blake and Frank Auerbach. In 1956, he saw an exhibition of contemporary American art at the Tate Gallery, and began to produce paintings in an abstract expressionist style.
In 1958, a year after leaving the Royal College, Morley moved to New York City (he has lived there ever since), met Barnett Newman, and became influenced by him. He painted a number of works at this time made up of only horinzontal black and white bands.
He also met Andy Warhol and Roy Lichtenstein and, influenced in part by them, changed to a photo-realist style (Morley prefers the phrase super realist). He often used a grid to transfer photographicss images (often of ships) from a variety of sources (travel brochures, calendars, old paintings) to canvas as accurately as possible, and became one of the most noted photo-realists.
In the 1970s, Morley's work began to be more expressionist, and he began to incorporate collage into his work. Many of his paintings from the mid-70s, such as Train Wreck (1975), depict "catastrophes". Later in the decade, he began to use his own earlier drawings and watercolours as the subject for his paintings.
In the 1990s he returned again to a more precise photo-realist style, often reproducing images from model aeroplane kits on large canvases.
In 1984, Morley won the inaugural Turner Prize.