Katz, Alex (1927- ), American painter who is best known for aloof, oversize portraits of his New York City friends, executed using bright colors and neatly simplified contours. Katz's work was central to the development of a movement in the art of the early 1960s called new realism. Although Katz's works reflect some aspects of abstract expressionism, a movement that dominated the New York art world of the 1950s, his work prefigured many of the concerns of the pop art movement, such as a fascination with American popular culture, especially Hollywood movies and roadside billboards.

Katz was born in Brooklyn, New York. He studied at the Cooper Union for the Advancement of Science and Art in New York City from 1946 to 1949 and at the Skowhegan School of Painting and Sculpture in Maine (summers of 1949 and 1950), where he later also taught. In New York City in the early 1950s, Katz developed friendships with many of the painters associated with American abstract expressionism. He began to paint human figures in a cool, flat manner, combining a focus on the flat surface of the canvas—an approach associated with the abstract expressionists—with his own interest in the science of perception and the art of illusion.

From the late 1950s, Katz found his favorite subject matter in his friends, many of them well-known personalities of the New York City art world, as in Portrait of Elaine de Kooning (1965, Private Collection, New Jersey). His interest in popular culture became more evident beginning in 1962, when he started enlarging both his pictures and the images within them, as in Eli (1963, Whitney Museum of American Art, New York City), in which the subject's face is cropped as in a cinematic close-up or a commercial advertisement. Since the early 1960s, Katz has created life-size sculptural cutout portraits, using metal or wood and painting them back and front. In the early 1960s, he also began his collaborations with American choreographer Paul Taylor on distinctive set designs for modern dance performances.

Between 1976 and 1977, Katz painted 23 glamorous portraits of women, each portrait 6.1-m (20-ft) high, on billboards above New York City's Times Square. A book on Katz by popular novelist Ann Beattie was published in 1987, adding to his renown.