Peacemaker is an American superhero television series created by James Gunn for the streaming service HBO Max. Based on the eponymous character from DC Comics, the series is produced by the Safran Company and Troll Court Entertainment in association with Warner Bros. Television and with Gunn as showrunner. The first season is a spin-off of the film The Suicide Squad (2021) set in the DC Extended Universe (DCEU), further exploring jingoistic vigilante Chris Smith / Peacemaker. The second season is the first live-action series in the DC Universe (DCU), a "soft reboot" of the DCEU, retroactively incorporating most of season 1 into the DCU's continuity, and taking place after the events of the film Superman (2025). It was produced by DC Studios with Gunn returning as showrunner.

John Cena stars as the title character, reprising his role from The Suicide Squad, with Danielle Brooks, Freddie Stroma, Chukwudi Iwuji, Jennifer Holland, Steve Agee, and Robert Patrick also starring in the first season, with Frank Grillo joining the cast in the second season. Although the character was originally slated to be killed in The Suicide Squad, Gunn conceived Peacemaker after noting Cena's strength as a dramatic actor, and wrote the first season while finishing the film. HBO Max ordered it straight-to-series in September 2020. Filming took place in Vancouver, Canada, from January to July 2021, with Gunn directing five episodes. He chose to use hair metal songs for the series' soundtrack, including "Do Ya Wanna Taste It" by Wig Wam for the dance sequence accompanying the first season's opening titles. A second season was ordered in February 2022, with Gunn again writing all episodes. The season was integrated with the DCU after Gunn was named co-CEO of DC Studios. Filming took place at Trilith Studios in Atlanta, Georgia, from April to November 2024.

Peacemaker premiered on January 13, 2022, with its first three episodes. The other five episodes of the first season were released weekly until February 17. Viewership increased with each episode and the season received mostly positive reviews. The second season premiered on August 21, 2025, and released weekly until October 9. Following the conclusion of the second season, Gunn announced there were no plans for a third season. The series has been nominated for several awards, including a Primetime Creative Arts Emmy Award. A spin-off series, Waller, is in development as part of the DCU.

The first season follows Chris Smith / Peacemaker after he recovers from the injuries he suffered during the events of the DC Extended Universe (DCEU) film The Suicide Squad (2021). Peacemaker is forced to join the mysterious A.R.G.U.S. black ops squad "Project Butterfly", who are on a mission to identify and eliminate parasitic butterfly-like creatures who have taken over human bodies around the world. The second season is set in the DC Universe (DCU) after the events of the DCU film Superman (2025). It follows Peacemaker finding an alternate universe where he is a beloved hero alongside his brother and father.

While completing work on the DC Extended Universe (DCEU) film The Suicide Squad (2021) in August 2020, writer and director James Gunn began writing a spin-off television series centered on the character Peacemaker portrayed by John Cena. DC Films president Walter Hamada approached the filmmakers of the studio's film slate about creating interconnected spin-off television series for the streaming service HBO Max, and the service ordered Peacemaker straight-to-series in September 2020. Gunn was writing all eight episodes of the first season and directing five. He and Peter Safran were set as executive producers, with Cena as co-executive producer. The season was produced by Gunn's Troll Court Entertainment and the Safran Company in conjunction with Warner Bros. Television. Matt Miller joined as an additional executive producer in December 2020.

HBO Max announced a second season of Peacemaker in February 2022, with Gunn set to write and direct all episodes. That April, Discovery, Inc. and Warner Bros.' parent company WarnerMedia merged to become Warner Bros. Discovery (WBD), led by president and CEO David Zaslav. The new company was expected to restructure DC Entertainment and Zaslav began searching for an equivalent to Marvel Studios president Kevin Feige to lead the new subsidiary. Gunn and Safran were announced as the co-chairs and co-CEOs of the newly formed DC Studios at the end of October 2022. A week after starting their new roles, the pair had begun working with a group of writers to develop an eight-to-ten-year plan for a new DC Universe (DCU) that would be a "soft reboot" of the DCEU. Gunn and Safran said some cast members would return from The Suicide Squad and Peacemaker in the DCU, and a "rough memory" of those events would remain in the new universe. Because Gunn was busy with his new responsibilities, the second season of Peacemaker was put on hold by January 2023.

Later in 2023, Gunn said the second season was his next project after the DCU film Superman (2025), and said it would be part of the DCU's Chapter One: Gods and Monsters slate of content. He stated that the first season was not canon to the DCU, but later clarified that most of the first season's events are canon to the DCU except for specific moments such as the appearance of the DCEU's Justice League. In March 2024, Gunn said filming for the second season would take place simultaneously with Superman later that year, in the interest of getting the season ready as soon as possible, so he was no longer able to direct all of the episodes.

With the series order in September 2020, John Cena was confirmed to be reprising his role as Peacemaker from The Suicide Squad. The next month, Gunn's close friend Steve Agee joined the series as John Economos, also returning from the film. In November, Gunn's then-girlfriend Jennifer Holland joined as her The Suicide Squad character Emilia Harcourt, alongside Danielle Brooks as Leota Adebayo, Robert Patrick as Auggie Smith, and Chris Conrad as Adrian Chase / Vigilante. Holland was surprised that Gunn brought her character back for the series, believing that her part in The Suicide Squad would be a short one-off role. Chukwudi Iwuji joined the cast as Clemson Murn in December. In late May 2021, Freddie Stroma was cast to replace Conrad as Adrian Chase / Vigilante, after Conrad left the series due to creative differences.