Arrow

Tatsu Yamashiro/Katana

Mentor of Oliver while he was in Hong Kong and nurses him back to health when he is nearly killed by Ra's al Ghul in "The Climb"

Floyd Lawton/Deadshot

Mercanary who killed Andy Diggle,John's brother, and member of the Suicide Squad who was killed while on a mission in "Suicidal Tendancies"

Malcolm Merlyn

New head of the League of Assassins after Oliver kills Ra's al Ghul in"My Name is Oliver Queen"

Felicity Smoak

Vice President of Palmer Industries and Oliver's Tech Support

Slade Wilson/Deathstroke

A former ASIS soldier ship-wrecked on Lian Yu who becomes a mentor to Oliver then becomes his enemy in season 2

Laurel Lance/Black Canary

Assistant District Attorney who eventually becomes Black Canary in honor of her sister.

Nyssa al Ghul

Daughter of Ra's al Ghul who trains Laurel to be a better hero.

Oliver Queen/The Arrow/Al Sah-him/Green Arrow

Expert Archer who was stuck on an island for 5 years and then came back to Starling City as The Arrow until Ra's al Ghul forced him to becom his succsessor

Quentin Lance

Father of Sara and Laurel and police captain of the SCPD

John Diggle

Former United States Army Special Forces soldier who is hired as Oliver's bodyguard

Roy Harper/Arsenal

Former criminal who is taken under the Arrow's wing and fakes his death to save Oliver

Ra's al Ghul

Former head of the League of Assassins until he was killed by Oliver in "My Name is Oliver Queen"

Thea Queen/(Speedy?)

Half-sister of Oliver who was killde by Ra's al Ghul in "Broken Arrow" and resurrected in "The Fallen" and becomes a vigilante after Roy gives her his old Arsenal suit which he customized to fit he.

Maseo Yamashiro

Husband of Tatsu who joins the League of Assassins after the death of their son. Killed by Tatsu in "This is Your Sword"

Sara Lance/Canary/White Canary

Sister of Laurel who was believed to have died on the Queen's Gambit then returned to Starling City as Canary until she was killed by a drugged Thea. Expected to be resurected by the Lazurus Pit and become White Canary during DC's Legends of Tomorrow.

Ray Palmer/The Atom

The new head of Queen Consolidated who builds a high tech suit and uses it to protect Starling City. Was last seen trying to give his suit the ability to shrink.