James McMullan (born June 1934) is an illustrator and designer of theatrical posters. Born in Tsingtao, China, where his grandparents had emigrated from Ireland as missionaries for the Anglican Church, he and his mother fled to Canada at the onset of World War II. In 1944, he enrolled at St. Paul's Boarding School in Darjeeling, India. After his father was killed in a plane crash, he joined his mother in Shanghai, and the two relocated to Vancouver Island, where he completed his high school education. When McMullan was 17, he and his mother emigrated to the United States, where he studied for a year at the Cornish College of the Arts in Seattle. He joined the United States Army and served at Fort Bragg in North Carolina, where he drew diagrams of where to position propaganda loudspeakers on Sherman tanks. In 1955, McMullan moved to New York City to continue his art education at Pratt Institute. While studying there he supported himself by illustrating book jackets for authors such as Lawrence Durrell and Jorge Luis Borges. He also did magazine illustrations for Esquire and Sports Illustrated, among others. In 1969, McMullan joined the fledgling New York Magazine and helped develop its graphic personality. His most notable contribution to the publication was the artwork illustrating the story about a Brooklyn discotheque that served as the basis for Saturday Night Fever.

McMullan's first theatrical poster was for the 1976 production of Comedians, produced by Alexander H. Cohen, who began to hire him on a regular basis. When Cohen's associate, Bernard Gersten, became Executive Producer of Lincoln Center Theater, he invited McMullan to join the organization. He eventually created more than forty posters for Lincoln Center productions, many of which are included in the 1998 book The Theater Posters of James McMullan. In 1981, McMullan published Revealing Illustrations, in which he candidly discusses his working method. He is the creator of the "High Focus" method of figure drawing, which he began teaching at the School of Visual Arts in He won a Drama Desk Special Award for his consistently inspired artwork for the theater in 1991.

McMullan and his wife Kate Hall have collaborated on six picture books for children.