Stephen J. "Steve" Ditko (born November 2, 1927) is an American comic book artist and writer best known as the artist and co-creator, with Stan Lee, of the Marvel Comics superhero Spider-Man, and as creator of the supernatural hero Doctor Strange.

Ditko studied under Batman artist Jerry Robinson at the Cartoonist and Illustrators School in New York City. He began his professional career in 1953, working in the studio of Joe Simon and Jack Kirby, beginning as an inker and coming under the influence of artist Mort Meskin. During this time, he then began his long association with Charlton Comics, where he did work in the genres of science fiction, horror, and mystery. He also co-created the superhero Captain Atom in 1960.

During the 1950s, Ditko also drew for Atlas Comics, a forerunner of Marvel Comics. He went on to contribute much significant work to Marvel, including co-creating Spider-Man, who would become the company's flagship character. Additionally, he co-created the supernatural hero Doctor Strange and made important contributions to the Hulk and Iron Man. In 1966, after being the exclusive artist on The Amazing Spider-Man and the "Doctor Strange" feature in Strange Tales, Ditko left Marvel for reasons never specified.