List of crossover episodes

This is a list of episodes which involve characters or plotlines from multiple shows in the Arrowverse. Since Arrow is the primary show and most crossovers involve characters from Arrow, they are arranged chronologically based on the Arrow timeline. The series in parentheses after each episode title list the show the episode is from first, then the shows from which other characters appear. There is then a brief plot description, covering just the basic interactions between crossover characters.

Season 3
Corresponds with The Flash season one and the web series Vixen (which takes place around the same time as The Offer).
 * The Calm (Arrow/The Flash) - Barry Allen calls Oliver Queen, saying he needs some advice.
 * Pilot (The Flash/Arrow) - Barry Allen takes Oliver Queen up on his offer, visiting Starling City to reveal his newfound powers and ask what he should do.
 * Going Rogue (The Flash/Arrow) - Felicity Smoak visits Barry Allen in Central City to see his superpowers for herself, meets and helps Team Flash, and assists them in defeating Leonard Snart, aka Captain Cold.
 * Flash vs. Arrow (The Flash/Arrow) - Oliver Queen, Felicity Smoak and John Diggle head to Central City looking for the boomerang killer, and help Team Flash fight Roy Bivolo, a meta-human who can cause uncontrollable rage in others. Oliver and Barry's differing methods cause tension between the two, and they are forced to fight when Bivolo uses his powers on Barry.
 * The Brave and the Bold (Arrow/The Flash) - Barry Allen, Cisco Ramon and Caitlin Snow visit Starling City to help Team Arrow defeat assassin Digger Harkness. While there, Cisco meets Detective Quentin Lance, and Barry and Oliver resolve their previous differences.
 * All Star Team Up (The Flash/Arrow) - Ray Palmer and Felicity Smoak visit S.T.A.R. Labs to get help perfecting Ray's A.T.O.M. Exosuit, and help Team Flash defeat a swarm of robotic bees.
 * Broken Arrow (Arrow/The Flash) - Cisco Ramon helps Team Arrow and Ray Palmer defeat the meta-human Jake Simmons, aka "Deathbolt", who has come to Starling City thinking no-one can stop him with the Arrow gone. Simmons is imprisoned in the Pipeline, but Cisco and Ray realise he was in Opal City during the dark matter wave, making the source of his abilities a mystery.
 * Who is Harrison Wells? (The Flash/Arrow) - Cisco Ramon and Joe West head to Starling City to investigate the real identity of Harrison Wells with the help of Quentin Lance. Cisco also meets Laurel Lance and upgrades her sonic device, renaming it the "Canary Cry".
 * Rogue Air (The Flash/Arrow) - Barry Allen decides to move the meta-humans from the Pipeline at S.T.A.R. Labs to the A.R.G.U.S. prison on Lian Yu, to protect them from the plans of the Reverse Flash. He enlists the help of Leonard Snart, but Snart double-crosses the Flash and frees most of the villains. Barry then fights the Reverse Flash, defeating him with the help of Oliver Queen and Firestorm.
 * My Name Is Oliver Queen (Arrow/The Flash) - Barry Allen briefly visits Nanda Parbat to save the members of Team Arrow, convincing them Oliver still needs their help.

Season 4
Corresponds with The Flash season two and DC's Legends of Tomorrow'' season one. It takes place after Constantine season one.''


 * Green Arrow (Arrow/The Flash) - in a flash-forward to six months in the future, Barry Allen visits Oliver Queen in a graveyard, apologising for missing a funeral. Oliver vows to kill "him", and asks Barry to leave before weeping over the grave.
 * Haunted (Arrow/Constantine) - in a flashback to his time infiltrating Baron Reiter's operation on Lian Yu, Oliver Queen meets John Constantine, saving his life while he is retrieving the Orb of Horus. In the present, Oliver calls in this favour from John to restore the soul of Sara Lance, who has been resurrected from the dead by the Lazarus Pit.
 * Lost Souls (Arrow/DC's Legends of Tomorrow) - Team Arrow, assisted by Curtis Holt, rescue Ray Palmer from Damien Darhk.
 * Legends of Today (The Flash/Arrow/DC's Legends of Tomorrow) - when Vandal Savage comes to Central City looking for Kendra Saunders, Team Flash ask Team Arrow to help keep her safe, but Carter Hall shows up claiming he and Kendra are reincarnated lovers. Savage follows them, and they learn from Malcolm Merlyn that Savage is an immortal looking for the Staff of Horus, and will stop at nothing until he finds it and kills both Carter and Kendra.
 * Legends of Yesterday (Arrow/The Flash/DC's Legends of Tomorrow) - Team Arrow and Team Flash work together to save Kendra Saunders and Carter Hall from Vandal Savage, who is willing to destroy both Central and Star Cities in his quest to kill them. They enlist the help of Malcolm Merlyn, who secretly recovers Savage's remains after he is turned to ash in the final conflict.
 * Season 4 episode 15 (Arrow/Vixen)- Vixen will make her live action debut helping team arrow.