Justice League: Crisis on Two Earths is a 2010 American animated superhero film directed by Lauren Montgomery and Sam Liu and written by Dwayne McDuffie. It is based on the abandoned direct-to-video feature Justice League: Worlds Collide, which was intended as a bridge between the DC Animated Universe series Justice League and Justice League Unlimited, and reworked to act as a standalone story.

Dwayne Glenn McDuffie was an American writer of comic books and television. He was best known for co-founding the pioneering minority-owned-and-operated comic book company Milestone Media, which focused on underrepresented minorities in American comics, creating and co-creating characters such as Icon, Rocket, Static, and Hardware. McDuffie was also known as a writer and producer for animated series such as Static Shock, Damage Control, Justice League Unlimited and the Ben 10 franchise.