Season 4 (Arrow)

Arrow was renewed for a fourth season on January 11, 2015. It will begin airing October 7, 2015 and will air during the 2015-2016 TV season.

Official synopsis
''After defeating his most formidable foe to date and riding off into the sunset with longtime flame Felicity Smoak, Oliver Queen (a.k.a. The Arrow) left Starling City with the hopes of beginning a new life. But will Oliver ever truly be able to leave behind his past as the Arrow, and, if so, what becomes of the team he has worked so hard to assemble? Will Diggle, Thea, and Laurel be left to continue Oliver’s crusade without him? And with Malcolm Merlyn having ascended to the top of the League of Assassins as the new Ra's al Ghul, is anyone really safe?''

Main cast

 * Stephen Amell as Oliver Queen/Green Arrow
 * Katie Cassidy as Laurel Lance/Black Canary
 * David Ramsey as John Diggle
 * Willa Holland as Thea Queen
 * Emily Bett Rickards as Felicity Smoak
 * John Barrowman as Malcolm Merlyn
 * Paul Blackthorne as Quentin Lance
 * Neal McDonough as Damien Darhk

Recurring cast

 * Brandon Routh as Ray Palmer/The Atom
 * Alexander Calvert as Lonnie Machin/Anarky
 * Echo Kellum as Curtis Holt/Mr. Terrific
 * Jimmy Akingbola as Baron Reiter
 * Caity Lotz as Sara Lance
 * Jeri Ryan as Jessica Danforth
 * Parker Young as Alex Davis
 * Rutina Wesley as Liza Warner
 * Elysia Rotaru as TBA

Confirmed plot points

 * There will be a crossover with The Flash ' s second season in the eighth episode.
 * The season's main antagonist will be Damien Darhk, introduced by name in the third season finale. He will have been operating for three months prior to the premiere.
 * The season will follow a lighter tone to that of season 3.
 * John Constantine will factor into the fallout of Sara Lance's resurrection.
 * Malcolm will don the Dark Archer hood in the third episode,.
 * Oliver will face a criminal organization known as Shadowspire in the flashbacks, led by Baron Reiter.

New characters

 * Jessica Danforth: A mayoral candidate who is deeply committed to her city and willing to risk her life to stand up for the people. Described as a female in her 50s-early 60s, Jessica is a peer and an old friend of the late Moira Queen, and was once close with Oliver and Thea. She is also a mother, and cares for her daughter above all else.
 * Lonnie Machin: A deranged freelancing criminal who is willing to do whatever it takes to impress a potential employer.
 * Curtis Holt: The tech genius and inventor who works under Felicity Smoak at Palmer Industries, at least when he’s not running around as his superhero alter ego.
 * Baron Reiter: Oliver's adversary seen in flashbacks. This grizzled, hardened and commanding man, who has no conscience and few compunctions, offers Oliver a job in his underground organization.
 * Alex Davis: A "smart and driven young man" who will be a possible love interest for Thea.
 *  Liza Warner: She will be a member of an anti-vigilante task force.