John Campbell grew up in Muncie, Indiana, where his parents worked for the creator of the comic strip Garfield. He moved to the East Coast to earn a degree in painting from the Rhode Island School of Design. His artwork draws its inspiration from Mughal and Indian miniature painting as well as religious and tribal art. He creates meticulously detailed worlds in a miniaturist style, incorporating characters from mythology into scenes where they take on new meaning. His artwork has been featured on the covers of the journals Nature and Neuron. He is also a free-lance science illustrator, with work appearing in the pages of Current Biology and in Harvard University research studies. In addition, he also assists his father in creating and cataloging The Puzzle Project, a conceptual work of art composed of over one thousand puzzle pieces cut from plywood.

He lives and works in Massachusetts.