The Challengers of the Unknown is a fictional group of adventurers appearing in comic books published by DC Comics. The quartet of adventurers explored paranormal occurrences while facing several fantastic menaces.

Jack Kirby was an American comic book artist, widely regarded as one of the medium's major innovators and one of its most prolific and influential creators. He grew up in New York City and learned to draw cartoon figures by tracing characters from comic strips and editorial cartoons. He entered the nascent comics industry in the 1930s, drawing various comics features under different pen names, including Jack Curtiss, before settling on Jack Kirby. In 1940, he and writer-editor Joe Simon created the highly successful superhero character Captain America for Timely Comics, predecessor of Marvel Comics. During the 1940s, Kirby regularly teamed with Simon, creating numerous characters for that company and for National Comics Publications, later to become DC Comics.