John Stewart is a recurring character in the Green Lantern mythos, usually serving as Earth’s most prominent Green Lantern due to the absence of some of the other notable ones (such as Hal Jordan, Kyle Rayner and/or Guy Gardner).

Stewart is an architect who was Hal Jordan’s backup, and occasionally filled in for him as Green Lantern when Jordan was unavailable. After Jordan gave up being Green Lantern in the 1980s, the Guardians selected Stewart to full time duty. Stewart filled that role for some years, during which time he married Katma Tui, the Green Lantern of the planet Korugar. After Tui’s murder, Stewart became the administrator of the “Mosaic World,” a patchwork of communities from multiple planets that had been brought to Oa by an insane Guardian. From this position, Stewart eventually ascended to Guardianhood, which he later relinquished. After a brief period of paraplegia, he became Green Lantern once again and is currently a member of the latest incarnation of the JLA. Stewart was also a member of the Darkstars for some time.

Template:Spoiler John Stewart (as voiced by Phil LaMarr) is one of the founding members of the Justice League in Justice League, where his characterization differs from the comics version by being a former Marine and having not been explicity revealed to have studied architecture. This is not the only difference: in a development not seen in any other version of the Green Lantern mythos, Stewart's eyes glow green as a side effect of his 15 years of exposure to the power ring's radiation (the glow fades when the ring runs out of juice). The ring is also effective against yellow, contradicting an age-old weakness of the Lantern Corps; this is in continuity with the earlier appearance of Kyle Rayner on Superman: The Animated Series. Despite these departures from his previous interpretation, though, John Stewart is arguably the most-developed main character in the show (excepting, of course, Batman and Superman, each of whom had their own solo DCAU television shows before Justice League even came into existence).

While specific details have been vague at best and absent at most (as in dates, places, exact events), a lot of the history of John Stewart can be determined through various comments and revelations over the course of the series. John grew up in an urban, predominantly African-American neighborhood, where as a kid, he was a big fan of "Justice Guild of America" comics (loosely based on the Justice Society of America; Bruce Timm never acquired the rights to the group). Stewart credits these comics with teaching him what it meant to be a hero. He accomplished this in human terms when he enlisted in the Marine Corps as a young man. His service dates are unknown, but it can be assumed it was at least for several years (given how much he absorbed the military's demeanor and methods into his own). It was here that John learned how to fight and strategize, as well as becoming a good friend of fellow Marine Rex Mason. After his service ended, he was chosen to be a Green Lantern, and went to go train in ring usage with Katma Tui, whom he also developed a romantic relationship with. It is unknown how the relationship ended. Because Sector 2814 - the one that includes Earth - had a Green Lantern already (Abin Sur), John spent 15 years patrolling another sector in the universe. It was during this time when, pursuing space pirate Kanjar Ro, John believed himself to be responsible for the destruction of the planet Ajuris 4 - later revealed to be a falsehood concocted by the Manhunters. When Abin Sur was murdered by Sinestro and passed his ring on to Kyle Rayner, John was transferred to take over 2814 so that Rayner could go off and train with Katma. It is at this point that Justice League joins John's story.

During the course of the series, John would be the main focus in more stories than any of the seven members of the League: In Blackest Night, Legends, Metamorphosis, The Savage Time, Hearts and Minds, Secret Society, and Starcrossed (although to be fair, he shares "main" focus with Wonder Woman in Savage and with Hawkgirl in Starcrossed). The most crucial development during this time, naturally, was the love story between him and Hawkgirl (real name: Shayera Hol). Their similar personalities ended up attracting each other and repelling each other at the same time, to the point where they became a bickering couple before they'd even decided to admit their feelings. Shortly after they did admit their feelings for each other, Starcrossed occurred, revealing that Hawkgirl was a spy for the Thanagarian forces, and that she has betrayed their secrets to her home planet (unfortunate for when the hawks officially take over). Worse than that, she'd been promised/engaged to the leader, Hro Talak, before she even came to Earth. Over the course of the Justice League finale, Shayera and Hol fell out of love with each other and Shayera helps save Earth from destruction. This doesn't quite help her standing of trust in the League, and she resigns without John ever telling her that he still loved her. During her self-imposed exile, the League expands to 57 members (in the retitled Justice League Unlimited) and John gets a new girlfriend: superheroine and supermodel Mari Jiwi McCabe/Vixen. This is a rebound relationship and he treats it like one; the second that Shayera returns to the League, he's torn about what to do and who to be with. This feeling gets exacerbated in The Once and Future Thing, when he travels to the future and meets his son with Shayera, Warhawk.

The other unique aspect of John's character is his self-loathing, in particular as applied towards being a superhero. Unlike many of the other Leaguers, John was a fighter before getting his superpowers, and his pride as a Marine is a bone of contention within himself now that he has this impossible weapon that can do anything. Because he spent 15 years in space on Lantern duty, he is a stranger to his home planet; he often relates events around him to similar things he saw out on his duty. In a certain way, John hates the ring for where it has led him and what it represents about him. He doesn't trust the Lantern's infinite power, and he is constantly looking for ways in which to reapply his Marine modes of thought and action into his work (training the Leaguers in Secret Society, joining Easy Company in The Savage Time, giving up the ring in Hearts and Minds). In In Blackest Night, he treats himself just as bad as the residents of Ajuris 5 do, claiming that superheroes need to be held accountable for their actions. In Metamorphosis, he deals with the opposite problem, noting how wealthy and carefree his old Marine pal Rex Mason is, and wonders if being the Lantern has cost him countless opportunities. And in Only a Dream, we go right inside John's head to see how he fears his hometown has become as alien to him as the farthest reaches of the galaxy, and how he worries about the Lantern energy being the only thing about him anymore. He conquers this fear (as Dr. Destiny harms his friends, John runs into the huge Lantern nearby and absorbs the energy into himself, making it his tool instead of himself being its tool), but he still has a chip on his shoulder. It would seem he blames himself for giving up real herosim (being a Marine) for just being a vessel for this boundless Lantern energy. To date, he has not really come to terms with it, and perhaps that is why he spends so much time with the Flash, who is completely earthbound in attitude and relationships, and feels only the extreme joy of his powers (although Flash is coming to some realizations about that, too).

When Bruce Timm first announced the lineup for Justice League, there was a good deal of commotion over two of the choices: John Stewart and Hawkgirl (how ironic; maybe they'll hook up?). With John, the first complaint was that he had been included just to have a black man on the team. Fans were angered for one of two reasons: 1. they were not including the "real" Green Lantern, Hal Jordan, or 2. they were not keeping in line with the continuity established in Superman by including Kyle Rayner. (These complaints tended to prove which were fans of particular League eras in comics - the former being fans of the Silver Age JLA, and the latter being fans of the modern Grant Morrison run.) The first thing that Timm did was admit that, yes, one of the reasons for John's inclusion was that he brought diversity to the team. He also felt that Stewart was a more interesting character (arguably, Jordan was too much of a square-jawed überhero and Rayner would be a lot like their Flash). Timm was fond to point to Dennis O'Neil's original incarnation of the character, who was an angry and edgy character, and it was from that position that they ran with it. They felt a character like this would bring conflict and interesting stories to the show; in addition to that, he's less-known amongst the Lanterns, so they were more able to shape the character as they saw fit. Despite these explanations, some fans still grumble about Stewart being there and Jordan not.

The other major controversy, especially amongst Internet fans, was Stewart's use of the ring. After the first few story-arcs, complaints began rising furiously over John's adherance to "beams and bubbles". Many felt they could accept this new character, but they couldn't accept this use of the superpower; after all, people were fans of the power of the Green Lantern because you could make anything with the ring. (Folks might also have been a little spoiled by the modern run of Green Lantern in the comics, with the comic artist Kyle Rayner bearing the ring and therefore spending practically every panel with a new and unique ring construct.) This is a controversy that the show itself has addressed in later episodes; in Hearts and Minds, Katma admonishes John for "using his ring like a jackhammer", a trait she attributes to half of the Corps. Additionally, John is much more free with his ring use when he's off-duty, as seen in Comfort and Joy when he makes himself a snowboard and has a superpowered snowball fight with Hawkgirl. That said, Timm has also admitted that they could have been more creative in the first season with John's power-ring usage, and in the latter parts of the second season and beyond, John has show more than the beams'n'bubbles variety he was first skewered for. Fans of the show have made a worthwhile point, however, that because John was (and practically is) a Marine, he would favor the results of his actions over the aesthetic interest of it, and his military thinking would motivate him to act first and consider later. That would help explain why he would favor smacking someone with a simple beam from his ring than inventing some new kind of sword, fist, mace, or whatever to achieve the same effect. As in-character as this explanation was, it was of little consolation to GL fans who wanted their ring usage to be as fun as they themselves would use it.

• The Book of OA
• The Green Lantern Shrine