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.

Arrow

2014-2015 Season

Includes Arrow season three, The Flash season one and the web series Vixen (which takes place around the same time as "The Offer").

Episode from	#	Episode name	Show(s) crossing over
Arrow S3	01.	"The Calm"	The Flash S1
	Barry Allen calls Oliver Queen, saying he needs some advice.
The Flash S1	01.	"Pilot"	Arrow S3
	Oliver Queen takes Barry Allen up on his offer. Barry then visits Starling City to reveal his newfound powers and ask what he should do.
	04.	"Going Rogue"	Arrow S3
	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.
	07.	"Power Outage"	Arrow S3
	Clock King, who previously appeared on Arrow is one of the villains on this episode.
	08.	"Flash vs. Arrow"	Arrow S3
	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.
Arrow S3	08.	"The Brave and the Bold"	The Flash S1
	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.
Vixen S1	01.-06.	"Episode 1 • 3 • 4 • 6"	Arrow S3 • The Flash S1
	Cisco Ramon uses Felicity Smoak's facial recognition software to look for meta-humans outside Central City and finds evidence of Mari McCabe using her animal powers against thugs in Detroit. He nicknames her "Vixen" and gives her whereabouts to Barry Allen, who decides to take backup; he and the Arrow show up at Mari's apartment. When Barry uses her name, she panics and runs away. Flash and the Arrow chase Mari, who uses various animal powers to evade them, including speed, wall-climbing, camouflage and flight. They eventually talk; Mari explains she was not in Central City for the particle accelerator explosion, a fact confirmed by Felicity Smoak, and refuses their offer of help, threatening them with violence if they return. Flash and the Arrow visit Mari again, offering to help train her if she intends to become a vigilante; she says she is, but wants to work things out on her own. She asks about getting a codename and Barry says they call her "Vixen"; he lets slip Cisco's name, giving her a clue as to his identity.
The Flash S1	18.	"All Star Team Up"	Arrow S3
	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.
Arrow S3	19.	"Broken Arrow"	The Flash S1
	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.
The Flash S1	19.	"Who is Harrison Wells?"	Arrow S3
	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".
	22.	"Rogue Air"	Arrow S3
	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.
Arrow S3	23.	"My Name Is Oliver Queen"	The Flash S1
	Barry Allen briefly visits Nanda Parbat to save the members of Team Arrow, convincing them Oliver still needs their help.

2015/2016

Includes Arrow season four, The Flash season two, Supergirl season one, 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, apologizing for missing a funeral. Oliver vows to kill "him", and asks Barry to leave before weeping over the grave. This scene takes place at the end of Canary Cry.
• "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 favor from John to restore the soul of Sara Lance, who has been resurrected from the dead by the Lazarus Pit.
• "Legends of Today" (The Flash/Arrow) - 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) - 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.
• "Pilot, Part 1" (DC's Legends of Tomorrow/Arrow/The Flash) - approached by Rip Hunter to be part of his time-traveling team, Ray Palmer seeks Oliver Queen's advice, and decides to join. Sara Lance, given the same offer, spars with her sister Laurel, who encourages her to go and be a hero. She gives Sara a new codename, "White Canary", and a new suit to go with it that doesn't include a mask. Martin Stein, Jefferson Jackson, Kendra Saunders, Carter Hall, Leonard Snart and Mick Rory are also recruited, all in order to stop Vandal Savage from conquering the world in the year 2166. They travel back in time to 1975 to meet Dr. Aldus Boardman, an expert on Savage, whose information would later help Team Arrow and Team Flash defeat Savage in 2015.
• "Pilot, Part 2" (DC's Legends of Tomorrow/Arrow) - at their first encounter with Vandal Savage in 1975 Norway, Rip Hunter's team find him selling a nuclear warhead at an illegal arms auction; one of the bidders is Damien Darhk, looking the same as he does in 2015, backed up by H.I.V.E. "ghosts".
• "King Shark" (The Flash/Arrow) - John and Lyla Diggle help to Barry to beat King Shark.
• "Taken" (Arrow/Vixen) - Mari McCabe helps Team Arrow.
• "Star City 2046" (DC's Legends of Tomorrow/Arrow) - When the team arrives in 2046, they meet Connor Hawke and an old Oliver Queen. And they team up to take down down Grant Wilson.
• "Worlds Finest" (Supergirl/The Flash) - Barry travels to National City on Earth-S and meets Kara Danvers.
• "Beacon of Hope" (Arrow/The Flash) - Brie Larvan from The Flash escapes from jail and kidnapped members of Team Arrow.
• "Left Behind" (DC's Legends of Tomorrow/Arrow) - Ray, Kendra and Sara are stuck in 1958. Sara decides to meet an old friend, Ra's al Ghul.
• "Canary Cry" (Arrow/The Flash) - Same Scene as Green Arrow where Barry visits Oliver at Laurel's grave apologising for missing her funeral due to Zoom. Oliver vows to kill Damien Darhk for killing her and asks Barry to leave before weeping over Laurel's grave.
• "Legendary" (DC's Legends of Tomorrow/Arrow) - Rip brings the team back home to 2016 where Sara returns to Star City and reunites with her father Quentin Lance who gives her the tragic news that her sister Laurel had died being killed by Damien Darhk and Sara wants to go back to the events of Eleven-Fifty-Nine to save Laurel but Rip tells her that he can't do that later Sara and Quentin visit Laurel's Grave where Sara tells her father that it was Laurel that convinced her to time travel in Pilot, Part 1 and she will continue for her sister.