Snowpiercer (Korean: 설국열차; Hanja: 雪國列車; RR: Seolgungnyeolcha) is a 2013 post-apocalyptic action thriller film based on the French climate fiction graphic novel Le Transperceneige by Jacques Lob, Benjamin Legrand and Jean-Marc Rochette. The film was directed by Bong Joon Ho and written by Bong and Kelly Masterson. An international co-production, the film marks Bong's English-language debut; almost 85% of the film's dialogue is in English.

The film stars Chris Evans, Song Kang-ho, Tilda Swinton, Jamie Bell, Octavia Spencer, Go Ah-sung, John Hurt, and Ed Harris, with Park Chan-wook and Lee Tae-hun among the film's producers. It takes place aboard the Snowpiercer train as it travels a globe-encircling track, carrying the last remnants of humanity after a failed attempt at climate engineering to stop global warming has created a new Snowball Earth. Evans stars as Curtis Everett, leader of the lower-class tail-section passengers, as they rebel against the elite of the front of the train. Filming took place at Barrandov Studios in Prague, using train car sets mounted on gimbals to simulate the train's motion.

Snowpiercer received critical acclaim and appeared on many film critics' top ten lists of 2014 after its international release, with praise for its vision, direction, and performances, particularly by Evans and Swinton. In the United States, the film was initially planned for a limited-screen showing, but the critical response prompted The Weinstein Company to expand the showing to more theaters and to digital streaming services. With a budget of $40 million, it remains one of the most expensive South Korean productions ever. The fourth volume of the original Snowpiercer graphic novel series, Snowpiercer: Terminus, published in 2019, serves as a sequel to the film, establishing it as being set in the same continuity as the original graphic novels. The film was also the basis for a television series set in a different continuity that aired from 2020 to 2024, with Bong, Park and Lee serving as executive producers.

In 2014, an attempt to stop climate change via stratospheric aerosol injection catastrophically backfires, creating a new ice age that destroys life on Earth. For 17 years, the remnants of humanity shelter in a state-of-the-art self-sustaining circumnavigational train, the Snowpiercer, run by reclusive transportation magnate Wilford. The passengers on the train are segregated, with the elite in the extravagant front cars and the poor crammed into squalid tail compartments overseen by armed guards. There were children in the back cars who were taken to the front and assaulting an elite member was punishable by having one of their arms frozen in the outer cold and smashed to pieces.

Urged by his mentor Gilliam, Curtis Everett and his second-in-command, Edgar, lead the tail passengers in a revolt. They discover that the guards had no ammunition and overwhelm them. They free Namgoong Minsoo, a captive security specialist. For his assistance, they bribe him with Kronole, an addictive drug made from industrial waste. Namgoong also insists that his clairvoyant daughter, Yona, be freed. Curtis and his fellow revolutionaries discover that the protein bars they were being fed were made of dead cockroaches. Namgoong helps the tail mob progress, but they face guards armed with melee weapons, overseen by Minister Mason. Edgar is held hostage, but Curtis allows him to be killed to capture Mason, forcing her to order the remaining guards to surrender. The tail mob stays back, holding the guards captive, while Curtis takes Mason, Namgoong, Yona, skilled fighter Grey, and Tanya and Andrew (two parents who had their children taken from them) towards the front of the train.

Curtis's group travels through several opulent cars. Namgoong and Yona recognize a landmark outside and speculate that the ice may be thawing more and more with every passing year. The group reaches a schoolroom, where a teacher is indoctrinating the children on Wilford's greatness. A bald man brings eggs for the children to celebrate the train's eighteenth circumnavigation of the Earth. Then the bald man goes to the tail army and shoots them with automatic firearms hidden under the eggs. The captured guards are freed, as is Mason's henchman Franco. The teacher, who received a gun from the bald man, kills Andrew before Grey kills her. Franco broadcasts to the classroom his execution of Gilliam, which prompts Curtis to execute Mason in turn. Curtis's group moves on, but Franco catches up with them, killing Grey and Tanya. Franco is then seemingly killed by Curtis and Namgoong.

In the last compartment before the engine, Namgoong reveals that the reason he collected the Kronole was to use it as an explosive to escape the train with Yona, believing they can now survive outside, pointing out the melting ice outside. Curtis explains that in the early days of the train, the tail section resorted to cannibalism. Edgar was an infant when Curtis killed his mother, and Curtis was going to eat him when Gilliam offered his severed arm instead, stopping the bloodshed. Curtis wants to confront Wilford for causing such horrors. Wilford's assistant, Claude, emerges from behind the engine room door to invite Curtis inside.

Curtis meets Wilford and, to his shock, learns that he and Gilliam conspired to stage Curtis's rebellion to reduce the tail section's population to sustainable levels. After ordering the execution of most of the tail section residents, Wilford offers Curtis his position leading the train. Curtis appears ready to accept as Yona overpowers Claude, rushes in, and asks for a match. In desperation, she pulls open a floorboard to reveal Tanya's son, Timmy, who has been enslaved to work as a replacement for a broken machine part. Appalled, Curtis pummels Wilford and rescues Timmy from the machinery, losing his arm in the process. Andy, Andrew's missing son, crawls out of a nook and climbs into the engine core despite Curtis's pleas. Curtis gives Yona the match to light the fuse for the Kronole bomb, while Namgoong fights and kills Franco, who followed them. Damaged by the fighting, the door to the engine room cannot be closed, forcing Curtis and Namgoong to use their bodies to protect Yona and Timmy from the blast.