Star Trek: Section 31 is a 2025 American science fiction television film directed by Olatunde Osunsanmi and written by Craig Sweeny for the streaming service Paramount+. It is the first television film, and the fourteenth film overall, in the Star Trek franchise and part of executive producer Alex Kurtzman's expanded Star Trek Universe. A spin-off from the series Star Trek: Discovery, the film is set in the franchise's "lost era" between the Star Trek: The Original Series films and the series Star Trek: The Next Generation. It follows Philippa Georgiou as she works with Section 31, a secret division of Starfleet tasked with protecting the United Federation of Planets, and must face the sins of her past.

Michelle Yeoh stars as Georgiou, reprising her role from Discovery. Development on a spin-off series with Yeoh was confirmed in January 2019, but production was delayed by the COVID-19 pandemic. A different Discovery spin-off series, Star Trek: Strange New Worlds, was then prioritized. Section 31 was redeveloped into a film, which was announced in April 2023. Omari Hardwick, Sam Richardson, Robert Kazinsky, Kacey Rohl, Sven Ruygrok, James Hiroyuki Liao, Humberly González, and Joe Pingue also star. Filming took place in Toronto, Canada, from January to March 2024. The film was produced by CBS Studios in association with Secret Hideout, Action This Day!, and Roddenberry Entertainment.

Star Trek: Section 31 was released on Paramount+ on January 24, 2025. Many critics gave it a negative review, with several finding it to be the worst entry in the Star Trek franchise. The film received several accolades, including a Primetime Creative Arts Emmy Award nomination for its sound editing. It was nominated for five Golden Raspberry Awards.

In the Mirror Universe, an alternate universe governed by the ruthless Terran Empire, a teenage Philippa Georgiou returns home from a deadly contest to determine the next Emperor. She reveals to her family that she befriended a boy named San and they defeated the other young contestants together. To claim the throne, Georgiou cuts all ties to her previous life by poisoning her family. Imperial officials arrive with San, who failed to kill his own family, and Georgiou enslaves him as she ascends the throne.

In the Prime Universe in the early 24th century, agents of the secret Starfleet division Section 31 are sent to the space station Baraam outside Federation space. Georgiou, having traveled to the Prime Universe and joined Starfleet for a time, poses as Baraam proprietress "Madame du Franc". Section 31 agent Alok Sahar convinces Georgiou to join his team, which includes: Melle, an irresistible Deltan; Quasi, a shapeshifting Chameloid; Zeph, the user of a mechanical exoskeleton; Rachel Garrett, a no-nonsense Starfleet officer; and Fuzz, a microscopic Nanokin who pilots a robotic suit that looks like a Vulcan. They intercept arms dealer Dada Noe on Baraam and Georgiou puts a "phase pod" on the weapon he is selling so only those with their own phase pod can touch it. A masked figure with a phase pod takes the weapon and kills Melle. Before the intruder transports off the station, Georgiou recognizes the weapon as the "Godsend" which she had ordered the development of in the Mirror Universe. It is designed to destroy everything in its path.

Alok gains Georgiou's trust by revealing his backstory: he is originally from the 20th century and his family were murdered during the Eugenics Wars by a genetically-enhanced warlord named Giri, who enhanced Alok and had him commit atrocities in her name. The pair question Dada Noe in a Section 31 safe house and learn that he is from the Mirror Universe, he stole the Godsend from a weapons facility, and he was selling it to the Terran Empire who are planning to enter the Prime Universe through a wormhole and conquer it. When the safe house is sabotaged and their ship is destroyed, the Section 31 team believes the masked man was tipped off by one of their own. Zeph disappears and the others suspect him of being the mole, but they find him dead and evidence implicates Garrett as the killer. Georgiou deduces that Fuzz infiltrated Zeph's exoskeleton, forced him to sabotage their communications and then kill himself, and planted the evidence. Fuzz is transported away, but first he reveals that San—who Georgiou thought was dead—is the masked man.

The team uses an abandoned garbage scow to follow San. Quasi and Garrett take out San's shields with the scow's tractor beam while Georgiou and Alok transport onto his ship. Alok fights Fuzz's robotic suit, but Fuzz leaves the suit to attack the scow. San intends to destroy the Prime Universe with the Godsend and create his own empire that will be ruled with "righteous mercy" in contrast to Georgiou's cruel dictatorship. As the pair fight, the Godsend is inadvertently activated. Garrett rigs an explosive from the scow's garbage which Quasi jettisons into space, seemingly killing Fuzz. San tries to stab Georgiou but she blocks him and he fatally stabs himself, dying in her arms. Alok and Georgiou decide to fly San's ship through the wormhole, sacrificing themselves while directing the Godsend into the Mirror Universe. Quasi transports them off the ship at the last moment.

Three weeks later, the surviving members of the team reconvene on Baraam. They are joined by Fuzz's wife, Wisp, who pilots an identical Vulcan robotic suit and believes her husband survived the explosion. "Control", the director of Section 31, contacts the team about their next mission which is on Turkana IV.