The Flash
(s1e1-23)
10/07/2014-05/19/2015
Barry Allen, a crime-scene investigator, gains superhuman speed from an explosion at S.T.A.R. Labs and becomes the costumed superhero the Flash. He uses his new powers to fight criminals along with other metahumans who have also gained superhuman abilities in Central City.
Arrow
(s3e1-23)
10/08/2014-05/13/2015
Following Sara's murder and the loss of his family's company to Ray Palmer, Oliver refuses to believe he can lead a normal life whilst continuing as The Arrow. He becomes embroiled in a conflict with Ra's al Ghul, in order to protect his sister Thea. Felicity becomes vice-president of the now renamed Palmer Technologies and Laurel sets out to follow in Sara's footsteps, assuming the mantle of Black Canary. The season's flashbacks see Oliver escape Lian Yu, only to be forced to work with Waller in Hong Kong, attempting to stop the release of a lethal pathogen.
Constantine
(s1e1-13)
10/24/2014-02/13/2015
John Constantine, a demon hunter and dabbling master of the occult, must struggle with his past sins while protecting the innocent from the converging supernatural threats that constantly break through to our world due to the "Rising Darkness". Balancing his actions upon the line of good and evil, Constantine uses his skills and a supernatural scry map to journey across the nation to send these terrors back to their own world, all for the hope of redeeming his soul from eternal torment.
Vixen
(s1e1-6)
08/25/2015-09/29/2015
After her parents were killed in Africa by local corruption, Mari McCabe inherits her family's Tantu Totem, gaining the powers of the animal kingdom, using them to fight as Vixen to stop threats like those that claimed her family.
Viewing Order
Arrow (Season 3 Episode 1)
The Flash (Season 1 Episode 1)
Constantine (Season 1 Episode 1)
The Flash (Season 1 Episode 2)
Arrow (Season 3 Episode 2)
The Flash (Season 1 Episode 3)
Constantine (Season 1 Episode 2)
Arrow (Season 3 Episode 3)
The Flash (Season 1 Episode 4)
Arrow (Season 3 Episode 4)
Constantine (Season 1 Episode 3)
Arrow (Season 3 Episode 5)
The Flash (Season 1 Episode 5)
Arrow (Season 3 Episode 6)
Constantine (Season 1 Episode 4)
The Flash (Season 1 Episode 6)
Arrow (Season 3 Episode 7)
The Flash (Season 1 Episode 7)
Constantine (Season 1 Episode 5)
The Flash (Season 1 Episode 8)
Arrow (Season 3 Episode 8)
Constantine (Season 1 Episode 6)
The Flash (Season 1 Episode 9)
Arrow (Season 3 Episode 9)
The Flash (Season 1 Episode 10)
Arrow (Season 3 Episode 10)
The Flash (Season 1 Episode 11)
Arrow (Season 3 Episode 11)
Constantine (Season 1 Episode 7)
The Flash (Season 1 Episode 12)
Arrow (Season 3 Episode 12)
The Flash (Season 1 Episode 13)
Arrow (Season 3 Episode 13)
The Flash (Season 1 Episode 14)
Arrow (Season 3 Episode 14)
Constantine (Season 1 Episode 8)
Constantine (Season 1 Episode 9)
Arrow (Season 3 Episode 15)
The Flash (Season 1 Episode 15)
Vixen (Season 1 Episodes 1-6)
Arrow (Season 3 Episode 16)
The Flash (Season 1 Episode 16)
Constantine (Season 1 Episode 10)
Arrow (Season 3 Episode 17)
The Flash (Season 1 Episode 17)
Arrow (Season 3 Episode 18)
The Flash (Season 1 Episode 18)
Constantine (Season 1 Episode 11)
Arrow (Season 3 Episode 19)
The Flash (Season 1 Episode 19)
Arrow (Season 3 Episode 20)
The Flash (Season 1 Episode 20)
Constantine (Season 1 Episode 12)
Arrow (Season 3 Episode 21)
The Flash (Season 1 Episode 21)
Arrow (Season 3 Episode 22)
The Flash (Season 1 Episode 22)
Constantine (Season 1 Episode 13)
Arrow (Season 3 Episode 23)
The Flash (Season 1 Episode 23)
2014-2015
Earth-1
Arrow
The Flash
Constantine
Vixen
Flash vs Arrow
The Flash (Season 1 Episode 8)
Arrow (Season 3 Episode 8)
The Flash Crossover
The Flash begins to crossover with multiple Elseworlds (also known as Earths). Most of them are contained within the Arrowverse.
Listed is an Elseworld that gets referenced to a lot, but also has some crossovers beginning with Elseworlds and continuing until Crisis on Infinite Earths.