John Semper Jr. is an American screenwriter, producer and story editor with numerous credits in animation for television.
He has worked for miscellaneous companies as Walt Disney Studios, Warner Bros. Animation and Hanna-Barbera Productions during a career which has involved the development of projects for Jim Henson, George Lucas, Stan Lee, Rob Minkoff and others.
Semper created the English-language dialogue for two of Hayao Miyazaki's acclaimed anime feature films Castle in the Sky and Kiki's Delivery Service, and co-wrote the screenplay for the live-action comedy Class Act.
During the 1990s, Semper was producer/story editor of Spider-Man: The Animated Series. which ran from 1994 to 1998.
In 2016, he began writing a Cyborg series for DC Comics drawn by Brian Stelfreeze.