American painter, printmaker, and writer best known for his naturalistic painting as well as his sophisticated writing on a variety of subjects. As a figurative painter at the height of Abstract Expressionism in the 1950s, Porter painted representational subjects heavily informed by contemporary directions in abstraction.

Porter, whose father was an architect, grew up with an appreciation for art. He studied art history and fine arts at Harvard University from 1924 to 1928 and then attended the Art Students League in New York for two years, working under Thomas Hart Benton (Benton, Thomas Hart). After traveling abroad for several years and then returning home to Illinois, Porter eventually settled in New York in 1942. There he continued to write art criticism, a genre he had first essayed while editing Arise, a short-lived socialist periodical. Porter became the associate editor at ARTnews in 1951 and wrote on the latest trends in contemporary art despite his own predilection for paintings of his family and friends and the scenery around his Long Island home and around his summer home on Great Spruce Head Island, Maine.

Porter's painting career was greatly influenced by Édouard Vuillard (Vuillard, Édouard) and Pierre Bonnard (Bonnard, Pierre), a show of whose paintings he had seen in 1938 at the Art Institute of Chicago. The works of these two painters, together with those of Diego Velázquez (Velázquez, Diego), revealed to Porter that nature could be transcribed by means of rich brushwork and interlocking patterns of colour, thereby making the ordinary extraordinary. Porter's friendship with Willem de Kooning (de Kooning, Willem), whom he met in the late 1930s, was also critical to his developing a fluid style and bold use of paint. Porter chose interior scenes, simple domestic props, and quiet landscapes as the subjects for his paintings. But these references to reality were only armatures for the sophisticated play of colour, form, and line that he would so capably engage for his entire career.

Selections from Porter's art criticism are gathered in Art in Its Own Terms: Selected Criticism, 1935–1975 (1979), edited by Rackstraw Downes.