|Appeared in||Green Lantern|
- "Individually, we are vulnerable. Together, we are unstoppable!"
- ―Thaal Sinestro [src]
Thaal Sinestro is a member of the Green Lantern Corps from the planet Korugar. He is the Green Lantern of sector 1417 and is mentor to Hal Jordan. He is 6ft7 and weighs 204lbs. Considered by many to be the greatest Green Lantern in the Corps, he is a true adversary to any that oppose him.
When Abins Sur was on his way to assist fellow Green Lantern Fentara, he was contacted by Sinestro who informed him that Fentara had been killed and warned him to be careful. Devastated by Sur's death he addressed the Guardians of the Universe. When Hal Jordan arrived on Oa as Abin Sur's replacement, Sinestro wasn't pleased that he was a human, stating that it disappointed him that Hal was wearing Sur's ring. This caused Hal to see himself unfit for the training so he returned to Earth. Sinestro and a few other members of the Corps confronted Parallax but couldn't stop him.
All the Green Lanterns who went on the mission were killed easily by Parallax except for Sinestro who refused to fight, seeing what happened to his fellow Corps members. Sinestro suggested the Guardians should forge a yellow power ring containing energy from the essence of Fear and use it to defeat Parallax because he thought you can only fight fear with fear. Hal arrived and told him not to use a yellow power ring because once corrupted by fear you can't turn back, he requested that Sinestro and the Guardians help him save the Earth from Parallax. His request, however, was denied so Hal had to defend his world on his own.
After leading Parallax towards the sun, Hal was about to be pulled into its core by gravity because he was exhausted and it was too strong for him to fight, when he was saved by Sinestro, Kilowog, and Tomar-Re. Sinestro commended Hal's achievements and told the Corps that the threat had been destroyed. After witnessing Fear's power, Sinestro retrieved the yellow power ring that had been created earlier, he slipped his green power ring off his finger, and replaced it with the yellow becoming the first Yellow Lantern.
- Hal Jordan - Student.
- Abin Sur - Best friend and ally; deceased.
- Tomar- Re - Ally.
- Kilowog - Ally.
- Parallax - Enemy; deceased.
Behind the scenes
- Jackie Earle Haley and Geoffrey Rush were both considered for the role of Sinestro before Mark Strong was cast.
- Mark Strong would later play Thaddeus Sivana in Shazam!.
- The design of Sinestro's Green Lantern uniform was incorporated into the DC comic 'Flashpoint'.
- Originally Sinestro was to lead a squadron of Lanterns to Earth to fight off Parallax. This was changed to having Hal beat Parallax on his own to make him more heroic, and having the squadron rescue him at the last moment.
- Mark Strong enjoyed working on this film, and was disappointed that he couldn't do a sequel.
- Early in the film when Abin-Sur and Sinestro are communicating on Abin-Sur's ship, just before Sinestro's hologram disappears,it momentarily becomes transfused with a flare of golden yellow (before disappearing altogether), foreshadowing his rise as a Yellow Lantern.
- In the comics, Sinestro's eyes are yellow with black sclera (in the humans it's white), but in the movie his eyes are green with white sclera. However, in the post-credits scene when he is possessed by Parallax his eyes turn yellow, a reflection of fear being the new source of his powers and in homage to his appearance in the comics.