The Justice League, also called the Justice League of America or JLA, is a fictional superhero team that appears in comic books published by DC Comics.
First appearing in The Brave and the Bold #28 (February/March 1960), the League originally appeared with a line-up that included Superman, Batman, Wonder Woman, Flash (Barry Allen), Green Lantern (Hal Jordan), Aquaman, and the Martian Manhunter. However, the team roster has been rotated throughout the years with characters such as Green Arrow, Captain Marvel, Black Canary, the Atom, Hawkman, Hawkgirl, Plastic Man, Red Tornado, Firestorm, Zatanna, other Green Lanterns, and dozens of others. The team received its own comic book title in October 1960, when the first issue was published, and would continue to #261 in April 1987, which was the final issue. Throughout the years, various incarnations or subsections of the team have operated as Justice League America, Justice League Europe, Justice League International, Justice League Task Force, Justice League Elite, and Extreme Justice.
Various comic book series featuring the League have remained generally popular with fans since inception and in most incarnations, its roster includes DC's most popular characters. The League concept has also been adapted into various other entertainment media, including the classic Saturday morning Super Friends animated series (1973–1986), an unproduced Justice League of America live-action series, and most recently the animated series Justice League (2001–2004) and Justice League Unlimited (2004–2006). A live-action film was in the works in 2008 before being shelved.
Source: Wikipedia, "Justice League", available under the CC-BY-SA License.