John Ostrander is an American writer of comic books. He is best known for his work on Suicide Squad, Grimjack and Star Wars: Legacy, series he helped create.
Originally an actor in a Chicago theatre company, Ostrander moved into writing comics in 1983. His first published works were stories about the character "Sargon, Mistress of War", who appeared the First Comics series Warp!, based on a series of plays by that same Chicago theatre company. He is co-creator of the character Grimjack with Timothy Truman, who originally appeared in a back up story in the First Comics title, Starslayer, before going on to appear in his own book, again published by First Comics in the mid 1980s. First Comics ceased publication in 1991, by which time Ostrander was already doing work for other comics companies (his first scripts for DC Comics were published in 1986).
Prior to his career in comic books, Ostrander studied theology with the intent of becoming a Catholic priest, but now describes himself as an agnostic. His in-depth explorations of morality were later used in his work writing The Spectre, a DC Comics series about the manifestation of the wrath of God. His focus on the character's human aspect, a dead police detective from the 1930s named Jim Corrigan, and his exploration of moral and theological themes brought new life to a character often thought of as impossible to write. He has also worked on Firestorm, Justice League, Martian Manhunter, Manhunter, Suicide Squad, and Wasteland for DC.