Greg Berlanti, who co-wrote the 2011 Green Lantern film, began developing a Green Lantern TV series for HBO Max in October 2019, initially envisioned as spanning several decades with two Earth-based Green Lantern stories and a space-set story about Sinestro.

Because Hal Jordan and John Stewart were reserved for DCEU films, Berlanti's original version focused on other Green Lanterns like Alan Scott, Guy Gardner, and Bree Jarta, with Finn Wittrock cast as Gardner and Jeremy Irvine cast as Scott before the project was scrapped.

After James Gunn and Peter Safran became co-CEOs of DC Studios in October 2022, the Green Lantern series was completely redeveloped to center on Hal Jordan and John Stewart as an Earth-based detective story rather than the space opera Berlanti had planned.

Tom King originally pitched the concept for the series, and showrunner Chris Mundy was hired by Gunn and Safran based on his work on Ozark and the fourth season of True Detective; Damon Lindelof joined because of his love for Ozark and King's comic books.

Josh Brolin was offered the role of Hal Jordan in 2024 but passed, and Matthew McConaughey and Ewan McGregor were also considered before Kyle Chandler was cast.

James Gunn had almost cast Aaron Pierre as Adam Warlock in Guardians of the Galaxy Vol. 3, and Pierre previously played Dev-Em in the DC series Krypton before landing the role of John Stewart in Lanterns.

Actors Damson Idris and Stephan James were also considered for the role of John Stewart before Aaron Pierre was cast.

Filming was originally planned for Atlanta, Georgia, but Gunn and Safran worked with Warner Bros. Discovery to secure tax credits allowing the production to shift to Los Angeles, partly to support the local industry after the January 2025 Southern California wildfires.

Hal Jordan's costume design, with a dusty leather jacket and salt-and-pepper hair, was inspired by his appearance in 1990s Green Lantern comics drawn by Pat Broderick, while his muted, faded green Lantern suit draws from the more grounded look of the Green Lantern: Earth One graphic novels.

The character of Hal Jordan was partly inspired by Sam Shepard's portrayal of Chuck Yeager in the 1983 film The Right Stuff.

The first teaser trailer featured Bruce Springsteen's song 'State Trooper' but was temporarily taken down a month later due to an expired music license before being re-uploaded with a different score.

Early marketing images and trailers drew attention and some criticism for the near-total absence of the color green and traditional Green Lantern costumes, leading to comparisons with grounded works like Fargo, No Country for Old Men, Logan, Yellowstone, and Reacher rather than typical superhero space opera.