In a universe as vast as it is mysterious, a small but powerful force has existed for centuries. Protectors of peace and justice, they are called the Green Lantern Corps. A brotherhood of warriors sworn to keep intergalactic order, each Green Lantern wears a ring that grants him superpowers. But when a new enemy called Parallax threatens to destroy the balance of power in the Universe, their fate and the fate of Earth lie in the hands of their newest recruit, the first human ever selected: Hal Jordan. Blake Lively as Carol Ferris: The vice president of Ferris Aircraft and a long-time love interest of Hal Jordan. Lively was chosen from a short list of potential candidates including Eva Green, Keri Russell, Diane Kruger and Jennifer Garner. About her stunt work in which she rehearsed with stunt coordinator Gary Powell (Casino Royale, The Bourne Ultimatum, Quantum of Solace), gymnastic acrobats from Cirque du Soleil and used aerial stunt rigs created for The Matrix, Lively explained, "Our director likes it real—the fights close and dirty... I'm 40 feet in the air, spiraling around. That's the best workout you can ever do because it's all core... You do that for ten minutes and you should see your body the next day! It's so exhilarating, so thrilling—and nauseating".
Hal is a gifted and cocky test pilot, but the Green Lanterns have little respect for humans, who have never harnessed the infinite powers of the ring before. But Hal is clearly the missing piece to the puzzle, and along with his determination and willpower, he has one thing no member of the Corps has ever had: humanity. With the encouragement of fellow pilot and childhood sweetheart Carol Ferris (Blake Lively), if Hal can quickly master his new powers and find the courage to overcome his fears, he may prove to be not only the key to defeating Parallax...he will become the greatest Green Lantern of all. Ryan Reynolds as Hal Jordan: A test pilot for the United States Air Force who becomes a Green Lantern and the first earthman ever inducted into the Green Lantern Corps. In an interview with MTV News Reynolds revealed; "I've known about 'Green Lantern' my whole life, but I've never really followed it before. I fell in love with the character when I met with Martin Campbell". About the film Reynolds stated; "It is an origin story to a certain degree, but it's not a labored origin story, where the movie begins in the third act. The movie starts when it starts. We find out Hal is the guy fairly early on, and the adventure begins". Alternatively Chris Pine and Sam Worthington had been in discussions for the role. Bradley Cooper, Jared Leto and Justin Timberlake screen tested, while Brian Austin Green, a Green Lantern fan, campaigned for the part, but ultimately did not audition. Mark Strong as Thaal Sinestro: A Green Lantern and Hal Jordan's mentor. In an interview with USA Today Strong affirmed that the film will follow the origin story, "the film closely follows the early comics. Sinestro starts out as Hal Jordan's mentor, slightly suspicious and not sure of him because obviously Hal is the first human being who's made into a Green Lantern. He's certainly very strict and certainly unsure of the wisdom of Hal becoming a Green Lantern". About the character Strong stated; "He is a military guy but isn't immediately bad. It's the kind of person he is that lends himself to becoming bad over the course of the comics being written, but initially he's quite a heroic figure." He also revealed that the outfit and other aspects of the character very closely follow the character's early days, "That widow's peak and thin mustache was for some reason originally based on David Niven, and Hal Jordan was based on Errol Flynn. In the '30s and '40s, they shared an apartment together in Hollywood when they were making movies and they were great friends. Obviously at the time, whoever was doing the original comics must have looked at them as guys doing very well in the film industry, and based those characters on them. So I would like to do justice to the Sinestro that was conceived for the comic books".[ His ship's crash-landing on Earth is witnessed by test pilot Hal Jordan (Reynolds), who rushes to the glowing wreckage to discover the mortally wounded Abin-Sur. The dying alien gives the confused Hal his ring and tells him to recite the oath before dying. Back in his apartment, Hal has the green lantern/power battery sitting on his coffee table where, amusingly, he tries reciting the oath ... but what's the oath? He was never told, so he starts a modified version of the Pledge of Allegiance (to the lantern rather than the flag) when suddenly the power battery bursts to life. Hal's eyes glow green as he begins to recite the Green Lantern's oath. ("In brightest day ..." you know the rest.) The battery and ring have formed some sort of psychic bond with Hal, imparting information to him.