Justice League is an American animated series about a team of superheroes, which ran from 2001 to 2004 on Cartoon Network. The series is based on the Justice League and associated comic book characters published by DC Comics. It follows the adventures of Superman, Batman, Wonder Woman, Green Lantern, The Flash, Hawkgirl, and Martian Manhunter. The series was immediately followed by Justice League Unlimited (2004–2006).

Starting this season, the episodes were produced in 16:9 widescreen which were letterboxed in 4:3 when broadcast.

Note: Chronologically, these episodes take place prior to "Starcrossed", as they make use of the original Watchtower and Shayera Hol still uses her "Hawkgirl" cover.^{[citation needed]}

Two spin-off comic book series (Justice League Adventures and Justice League Unlimited) were loosely set in the same continuity as the animated series. They feature characters who never appeared on the animated series such as Blue Beetle, Mary Marvel, Power Girl, Black Lightning and Firestorm. Power Girl's inclusion renders the issues out of continuity once Justice League Unlimited introduced Galatea into the animated series.

Matt Wayne (who wrote "Chaos at the Earth's Core", "Flash and Substance", and "Patriot Act") wrote issues 37 and 38 of the comic, based on unused episode ideas.