John Cullen Murphy (1919, New York City-2004, Greenwich, Connecticut) was the artist of the Prince Valiant comic strip. He replaced the strip's creator, Harold Foster, full-time in 1982 after Foster's death (Foster invited Murphy to collaborate with him in 1970). He continued to draw Valiant (with his son writing the script, and his daughter doing the lettering/coloring) until he retired in March 2004, turning the strip over to his hand-picked successor, illustrator Gary Gianni.
He attended the Art Institute of Chicago, where his family lived for a time. He aspired to be a baseball player, and was playing baseball when a neighbor, Norman Rockwell, asked the 15 year old if he would like to model for him. Rockwell's "Starstruck", in which a forlorn Murphy sits on the floor, gazing at pictures of movie starlets, was the September 22, 1934 cover of the Saturday Evening Post. Rockwell became one of Murphy's mentors.