DC's Legends of Tomorrow, or simply Legends of Tomorrow, is an American time travel superhero television series developed by Greg Berlanti, Marc Guggenheim, Andrew Kreisberg, and Phil Klemmer, who are also executive producers along with Sarah Schechter and Chris Fedak; Klemmer and Fedak originally served as showrunners, while Keto Shimizu became co-showrunner with Klemmer starting with the fourth season. The series, based on the characters of DC Comics, premiered on The CW on January 21, 2016, and ran for seven seasons until March 2, 2022, before its cancellation on April 29. It is a spin-off set in the Arrowverse and features characters introduced in Arrow and The Flash, along with new characters.

While the first season received mixed reviews, the series enjoyed improved reception in subsequent seasons, which saw a shift in tone, as well as frequent changes to both the setting, themes, and cast of characters as the show went on. Originally premiering as a self-serious superhero drama where heroes battle high stakes throughout time, the consensus of critics was that the show found its feet as a more light-hearted DC series associated with meta-humor, social commentary, and the greater creative freedom afforded to its cast of mainly lesser-known or wholly original characters.

In season one, Time Master Rip Hunter goes rogue after the immortal tyrant Vandal Savage conquered Earth and killed his wife and son, in what would be the future. Meanwhile, the organization he swore himself to, turns on him. Intending to save humanity and avenge his family, Rip recruits a team of superheroes and villains, consisting of Ray Palmer / the Atom, Sara Lance / White Canary, Martin Stein and Jefferson "Jax" Jackson / Firestorm, Kendra Saunders / Hawkgirl, Carter Hall / Hawkman, Leonard Snart / Captain Cold, and Mick Rory / Heat Wave, who venture through time on a stolen time ship, the Waverider, to stop Savage's rise to power. Meanwhile, the Time Masters send Chronos after Rip for interfering with the timeline and in the season's final episodes it turns out that the Time Masters were working with Savage all along, as his reign will eventually successfully counter an upcoming Thanagarian invasion of Earth. Snart also sacrifices himself to destroy the Time Masters.

In season two, following Snart's sacrifice while defeating the Time Masters, Rip goes missing and Sara takes charge of the team who continue protecting the timeline from aberrations. They are joined by historian Nate Heywood / Citizen Steel, who later gains the ability to turn to steel at will, and Justice Society of America member Amaya Jiwe / Vixen, who joins the Legends to pursue Eobard Thawne / Reverse-Flash, a speedster and Barry Allen's archenemy. After learning of the Spear of Destiny, an ancient artifact that can rewrite reality, Thawne recruits Damien Darhk, Malcolm Merlyn, as well as a time-displaced Snart, from different points in time to form the Legion of Doom. However, after retrieving the Spear, Sara successfully defeats Thawne and the Legion is returned to their proper times.

In season three, Rip forms the Time Bureau to replace the Time Masters and fires the Legends for causing anachronisms. When Bureau agent Ava Sharpe is captured, Rip is forced to take the Legends out of retirement. Elsewhere, the demonic entity Mallus forms a cult led by Darhk's daughter Nora, pursuing the six totems of Zambesi, two of which are wielded by Amaya and near-future hacktivist Zari Tomaz. The Legends, assisted by speedster Wally West, retrieve all the totems and use them to defeat Mallus.

In season four, after Rip's sacrifice during the fight against Mallus, occult detective John Constantine informs the Legends that Mallus was not the only demon that escaped and that "magical fugitives" are on the loose. John joins the team, along with shapeshifter Charlie and Mona Wu, who is host to a Kaupe, to stop them. Ava and Sara and Ray and Nora begin relationships, and Nora becomes a fairy godmother. The Legends come into conflict with the demon Neron, who was banished by John during a show at Heyworld intended to help humans be less afraid of the magical creatures. In addition, Neron manipulates Time Bureau member Gary Green into working for him. Following Neron's defeat, Zari's timeline changes and she is replaced as a Legend and wielder of the Air Totem by her brother Behrad.

In season five, Astra Logue, whom John accidentally sent to Hell in a botched exorcism, has resurrected evil individuals from history known as "Encores". Meanwhile, Charlie is revealed to be Clotho of the three Fates who is being pursued by her sisters to recover the Loom of Fate. Mona, Ray, Nora, and Charlie leave the Legends, who defeat the Fates and Encores. Astra joins the Legends, with John offering to be a roommate at his house and a mentor to her. Sara is captured by a mysterious beam.

In season six, it is revealed that Sara was kidnapped by Gary and his fiancé Kayla, who are both aliens. Sara's alien abduction was orchestrated by a scientist named Bishop, who created the Avas. He plans to create the perfect warrior by copying Sara's DNA and memories and combining it with other aliens upon claiming that he has seen the end of the human race. While attempting to escape her imprisonment, Sara accidentally releases a menagerie of aliens throughout the timeline, including Kayla, whom Mick becomes romantically involved with. To find Sara, the Legends enlist Esperanza "Spooner" Cruz, an off-the-grid recluse who can telepathically communicate with aliens following her own abduction, as they repel alien invasions throughout Earth's history. Bishop then goes after the Fountain of Imperium that would restore Constantine's powers, only to double-cross him and destroy it so that the Zagurons would invade Earth, but the Legends revive it and defeat Bishop with help from Bishop's younger counterpart. Mick, who now has several kids with Kayla, decides to leave the Legends. A duplicate Waverider destroys the original, stranding the Legends in 1925 Texas.