12 Monkeys is an American television series on Syfy created by Terry Matalas and Travis Fickett. It is a science fiction mystery drama with a time traveling plot loosely adapting the 1995 film of the same name, which was written by David and Janet Peoples and directed by Terry Gilliam, itself based on Chris Marker's 1962 featurette La Jetée; the series credits Marker and both Peoples for their original works.

In the series, Aaron Stanford and Amanda Schull star as James Cole and Dr. Cassandra "Cassie" Railly, two strangers brought together by destiny on a mission to use time travel to stop the destructive plans of the enigmatic organization "Army of the 12 Monkeys". Kirk Acevedo and Noah Bean also star in the first season. In the second season, Bean makes a guest appearance, and Todd Stashwick, Emily Hampshire, and Barbara Sukowa are promoted from recurring guests to regulars. In the fourth season, Acevedo moves from starring to recurring guest star. Stanford, Schull, and Hampshire play reimagined versions of characters respectively portrayed by Bruce Willis, Madeleine Stowe, and Brad Pitt in the 1995 film. Stowe made a guest appearance in the second season in a small but pivotal role.

Natalie Chaidez was the showrunner of 12 Monkeys during its first season, working closely with creators Matalas and Fickett. For the second season, she stepped down from the role of consultant and Matalas and Fickett became showrunners. In the third and fourth seasons Fickett became a consultant, and Matalas was the sole showrunner. The series was produced by Atlas Entertainment, which also made the 1995 film, and Universal Cable Productions. Charles Roven, producer of the original film, was one of the series executive producers.

12 Monkeys premiered on January 16, 2015, with a 13-episode first season which received mixed critical reception, and ended with the completion of its 11-episode fourth season on July 6, 2018, for a total of 47 episodes produced. From its second season and onward, it enjoyed more consistently favorable critical reception. The series won two awards for its cinematography, one by each of the American and Canadian Societies of Cinematographers, and was nominated for a further four.