The Justice Guild of America is a superhero team featured in the Justice League animated series two-part episode "Legends", an homage to the Golden Age Justice Society of America, and to a degree the Silver Age Justice League of America.

"Flash of Two Worlds!" is a landmark comic book story that was published in The Flash #123. It introduces Earth-Two, and more generally the concept of the multiverse, to DC Comics. The story was written by Gardner Fox under the editorial guidance of Julius Schwartz, and illustrated by Carmine Infantino. In 2009, DC Comics released a new digitally remastered graphic novel collection, DC Comics Classics Library: The Flash of Two Worlds. It features the classic flagship story and other subsequent pre-Crisis Flash material.