Green Lantern is missing from every live-action Justice League team, from Smallville to the Arrowverse to the DCEU. One of the founding members of the League, Green Lantern (usually Hal Jordan) is one of the core superheroes of DC Comics - and also one of the most powerful thanks to his signature weapon, the Power Ring that can conjure anything the Lantern can imagine. And yet, the Emerald Gladiator has been continually left out of every live-action incarnation of the Justice League so far.
For decades, Green Lantern has been a fixture in DC Comics and in various animated TV series, from the Superfriends in the 1970s-1980s to the Justice League animated series in the 1990s and the modern DC Animated films. But unlike his peers Superman, Batman, and Wonder Woman, Green Lantern has only had one live-action incarnation: the 2011 Green Lantern movie starring Ryan Reynolds. The failure of that film scrapped plans to establish Green Lantern's universe on the big screen, which led Warner Bros. to change gears and launch the DC Extended Universe with Superman (Henry Cavill) instead in Zack Snyder's Man of Steel. It has now been years since a reboot film titled Green Lantern Corps (rumored to star Tom Cruise at one point) was announced but it has failed to materialize.
While Green Lantern has been in limbo, three different live-action versions of the Justice League have emerged without him. Smallville assembled a Justice League with Clark Kent (Tom Welling) as its centerpiece, which included Aquaman (Alan Ritchson), Impulse (Kyle Gallner), and Zatanna (Serinda Swan). The Justice League finally came together on the big screen with Superman, Batman (Ben Affleck), Wonder Woman (Gal Gadot) among the DC Comics heavy hitters - but without Green Lantern on the team. And the Arrowverse has boasted dozens of superheroes teaming up in annual crossovers but Green Lantern is nowhere to be seen in The CW's Multiverse.
The only case that borderline counts is the 1997 CBS TV movie Justice League of America, which starred Matthew Settle as Guy Gardner, but that's widely regarded as a forgotten failed pilot. Amazingly, at this point, there have been more live-action versions of Green Arrow, Cyborg, The Flash, Aquaman, Martian Manhunter, and Black Canary than there has of Green Lantern!
To be fair, Green Lantern has been teased to exist in all of those different universes. A Green Lantern appeared in Justice League's "history lesson" although it was Yalan Gur, a ring-slinger who fought (and died) against Steppenwolf's invasion thousands of years ago. In the Smallville: Season 11 comics that continued the saga after the TV series ended, the Green Lanterns were introduced and Superman even wore a Power Ring. Meanwhile, Ferris Aircraft and Coast City, two staples of the Green Lantern mythos, have been part of the Arrowverse since Arrow season 1. Further, in last year's Elseworlds crossover, an alternate universe version of John Diggle (David Ramsey) was teased to be Green Lantern (the John Stewart version).
There are a few reasons why it's been so difficult to adapt Green Lantern into a live-action Justice League. One significant hurdle is how complex Green Lantern's mythology is; Hal Jordan isn't just one superpowered hero but as Green Lantern, he's actually part of a Corps of thousands of Emerald Gladiators across the universe. To fully establish Green Lantern means introducing the other members of the Green Lantern Corps, their overseers the Guardians of the Universe, and their rogue's gallery - a menagerie of aliens and cosmic beings. On a TV budget, this is a daunting prospect, and so are Green Lantern's powers, which includes being able to fly through outer space and an infinite variety of constructs he'd create with his Power Ring.
Since Green Lantern comes complete with elaborate powers and his own built-in universe that's bigger than the other superheroes', he's extremely difficult to weave into shared universes. This isn't to say it won't someday happen but, most likely, it'll be a big-budget feature film that finally brings Green Lantern back to live-action (and that movie needs to be a success). Although, given the current direction of the DCEU, that could mean an even longer wait before Green Lantern finally joins the live-action Justice League.