Secret identities

As a part of having an alter ego, characters try to keep secret identities, often telling as few people as possible about their alternate identity. Below are lists of characters' secret identities, and who is aware of them.

Barry Allen/The Flash

 * 1) Harrison Wells: After waking up from a coma, Barry discovered that he'd gained the power of super speed. Using this to his advantage, he eventually decided to become a guardian angel over Central City, with Wells among his team.
 * 2) Caitlin Snow: After waking up from a coma, Barry discovered that he'd gained the power of super speed. Using this to his advantage, he eventually decided to become a guardian angel over Central City, with Caitlin among his team.
 * 3) Cisco Ramon: After waking up from a coma, Barry discovered that he'd gained the power of super speed. Using this to his advantage, he eventually decided to become a guardian angel over Central City, with Cisco among his team.
 * 4) Oliver Queen: Before actually becoming The Flash, Barry consulted Oliver on what to do. Oliver motivated him to become The Flash, observing his super speed as he ran away.
 * 5) Clyde Mardon: After The Flash reversed Clyde's tornado, Barry took off his mask as Clyde snuck up on him, armed with a gun.
 * 6) Joe West: Before Barry was shot by Clyde, Joe shot Clyde himself numerous times. He shortly discovered that Barry had been given his powers from the bolt of lightning that had struck him.
 * 7) Felicity Smoak: When Felicity visited Barry in Central City, he showed her his newfound abilities.
 * 8) Bette Sans Souci/Plastique: After saving her from General Eiling, Barry reveal his identity to Bette and he's a Metahuman well.
 * 9) Tony Woodward/Girder: After defeating his childhood bully, Barry put Tony in the prison of metahumans.
 * 10) John Diggle: When he and the team (sans Roy) were in Central City on a mission, sped up to them, shocking Diggle ( When he and Felicity were talking, Barry speed towards them, shocking Diggle who was the only one that hadn't been told.
 * 11) Lyla Michaels: After coming to Starling City to meet Oliver, Barry accidentally let Lyla know that he was The Flash, assuming Diggle had told her.
 * 12) Roy Harper: Arriving back from getting sushi, Barry kept his mask off but the rest of his outfit on, letting Roy see.
 * 13) Reverse-Flash: Somehow Reverse-Flash knows who Barry is, even before the latter became The Flash, 14 years later, implying he is from the future.
 * 14) Henry Allen: After piecing together a number of interactions with The Flash, Henry concluded that he is Barry. Despite Barry shrugging the accusation off, Henry proceeded to admit how proud he was and assure that, if his son was actually The Flash, that he was doing real good.

Sara Lance/The Canary

 * 1) League of Assassins: The entire League, including the likes of Ra's al Ghul, Nyssa al Ghul and Al-Owal, were aware of Sara's vigilantism in Starling City, due to her having trained with them.
 * 2) Sin: After saving her from being raped by a group of men, Sara revealed her identity to Sin.
 * 3) Oliver Queen: Oliver trapped The Canary with a bunch of ropes attached to arrows, only to take off her mask to reveal Sara. He in turn revealed his identity.
 * 4) John Diggle: When Sara joined Oliver's team, she met Diggle and Felicity.
 * 5) Felicity Smoak: When Sara joined Oliver's team, she met Felicity and Diggle.
 * 6) Quentin Lance: When the League of Assassins began to hunt Sara down, under orders from Nyssa al Ghul, Sara decided that the best way to protect her family was to reveal her secret identity, thus giving them a full idea of the dangerous situation. She revealed this to her father, who was initially shocked at her appearance, though accepting of her actions.
 * 7) A.R.G.U.S.: Amanda Waller and Lyla Michaels were aware of who Sara was and what she did.
 * 8) Roy Harper: When Roy joined Oliver's team, he met its members, among them being Sara.
 * 9) Slade Wilson: When Slade began to hunt down Oliver and destroy him, Oliver's team fought back. In the midst of this, Slade was made aware of Sara still being alive, and further inferred Sara's vigilantism.
 * 10) Laurel Lance: When Laurel saw Sara's injuries after Slade's attack, she was nearly heartbroken on learning this.
 * 11) Caitlin Snow: After Felicity gave her some evidence to process in regards to The Canary's death, Caitlin openly called her "Sara", somehow knowing who The Canary was.
 * 12) Cisco Ramon: As Caitlin openly named The Canary as Sara, it seems as if Cisco was already aware as to her identity.

Laurel Lance/Black Canary

 * 1) Roy Harper/Arsenal: Roy learned about Laurel as Black Canary while stopping a mugger.
 * 2) John Diggle: Diggle learned about Laurel as Black Canary after Roy helped her.
 * 3) Felicity Smoak: Felicity learned about Laurel as Black Canary after hearing that The Canary is back believing it's not Sara.
 * 4) Ted Grant/Wildcat: Ted knew about Laurel as Black Canary after watching the news.
 * 5) Oliver Queen/The Arrow: Oliver learn about Laurel as The Canary.
 * 6) Quentin Lance: Her father knew Laurel has take her late-sister's place as a vigilante.

Malcolm Merlyn/The Dark Archer

 * 1) League of Assassins: The entire league, including Ra's al Ghul, Nyssa al Ghul and Al-Owal, are aware of Malcolm's secret identity, and are all unhappy about what he'd done.
 * 2) Oliver Queen's team: Following Malcolm's reveal to The Hood about him being The Dark Archer, Oliver's entire team is aware of Malcolm's alter ego.
 * 3) Tommy Merlyn: As they were being shot at by members of the Chinese Triad, Malcolm revealed his panic room to Tommy, fully equipped with his Dark Archer suit and equipment.
 * 4) Moira Queen: As they were both high ranking members of Tempest, it is unconfirmed but implied that she is aware of this secret.
 * 5) Thea Queen: As Thea was about to be attacked by one of Slade Wilson's army, Malcolm intervened and pulled off his mask to reveal his identity to her.

Oliver Queen/The Arrow
Oliver initially acted as a vigilante known as The Hood. However, a year later he began to be known as a hero, The Arrow.
 * 1) Lodai: Since Lodai is Oliver's supplier for all of his vigilante equipment and activities, it is very likely that he is aware of Oliver's secret identity.
 * 2) John Diggle: Oliver was forced to reveal his identity as The Hood when Diggle was shot by Deadshot, and had to recuperate in Oliver's base after being given medicine. Dig initially did not accept Oliver's vigilantism, but later was accepting and joined Oliver's vigilante team.
 * 3) Derek Reston: After saving his son, Derek was shot, and in his dying moments Oliver decided to reveal his identity to him, to prove that the always had his best interests at heart.
 * 4) Helena Bertinelli: After Oliver realized that Helena was The Huntress, he helped save her, and she in turn discovered The Hood's identity. Helena joined Oliver's team, helping to fight crime, however she was too blinded by her hatred for her father, and left.
 * 5) Felicity Smoak: Following Oliver being shot by Moira Queen when he tried interrogating her, he lay in the back of Felicity's car with a wound. He revealed his identity to her, and the two of them drove to Robert Queen's warehouse, where Oliver's base lay beneath. Once there, Felicity and Diggle operated on him.
 * 6) Tommy Merlyn: When his father, Malcolm, was shot by Deadshot, Oliver revealed his identity to Tommy in order to trust him to save his father's life. Tommy was conflicted over Oliver's revelation and often argued with him over his actions, though Tommy ultimately kept the secret.
 * 7) Webb: After trying to stop the production of Vertigo, Oliver was drugged with it and knocked out. He was strapped down, only to escape and kill Dr. Webb.
 * 8) Webb's accomplice: When Dr. Webb trapped Oliver, the two of them learnt his true identity. He was ultimately killed by John Diggle when he escaped.
 * 9) Malcolm Merlyn: Oliver went after Malcolm, who revealed his identity as The Dark Archer. Malcolm ultimately won the fight, pulling off Oliver's hood in shock.
 * 10) Sara Lance: For over a year Sara suspected Oliver to be The Hood, later The Arrow, and she finally discovered that her suspicions were true when her identity was revealed to Oliver. She joined Oliver's team not long after that.
 * 11) Al-Owal: Al-Owal broke in to the Queen Mansion while Sara was staying there. Not only did he know of her whereabouts, but he also knew of Oliver's alter ego, The Arrow. It's possible he knew it due to Malcolm, his former protégé, knowing it.
 * 12) A.R.G.U.S.: Some members of A.R.G.U.S., including the likes of Amanda Waller and Lyla Michaels, are aware of Oliver's secret identity, as well as his associates, John Diggle and Felicity Smoak.
 * 13) Count Vertigo: Count Vertigo was able to deduce Oliver's identity as The Arrow solely due to his large connection to Felicity Smoak, who also had a large connection to The Arrow. He used his knowledge of this connection to lure Oliver to Queen Consolidated, where Oliver confirmed his ideas of Oliver's identity, only to be killed when Count Vertigo almost killed Felicity.
 * 14) Barry Allen: Felicity and Diggle made the call to reveal Oliver's secret identity to Barry when Oliver was poisoned by unknown chemicals from an A.R.G.U.S. disaster bunker, following his fight with a Mirakuru-enhanced Cyrus Gold. Oliver was annoyed at this, though soon came to terms with it and accepted Barry.
 * 15) Slade Wilson: For the entire time that Oliver acted as The Hood, then The Arrow, Slade had figured that he was indeed Oliver, due to the green hood's significance - a reference to that of Yao Fei's and Shado's hood. He made it his sole purpose to destroy Oliver's life and reverse his heroic deeds.
 * 16) League of Assassins: The entirety of League of Assassins, including the likes of Ra's al Ghul, Nyssa al Ghul and Maseo Yamashiro who know about Oliver as The Arrow.
 * 17) Roy Harper: Oliver was forced to reveal his secret identity to a Mirakuru-enhanced Roy in order to calm him down, to stop him from beating Ben Turner to death. Roy later joined Oliver's team, but left the team, because he (correctly) blamed Oliver for Thea getting kidnapped by Slade Wilson.
 * 18) Isabel Rochev: Due to being in league with Slade Wilson, a fact which she eventually revealed to Oliver, Isabel was aware of Oliver being The Arrow.
 * 19) Laurel Lance: When Slade Wilson began publicly ruining Oliver's life, he turned up at Laurel's door to tell her of Oliver's identity as The Arrow. Laurel was initially shocked and began to add up the clues, but after advice from her father, decided that it was best to not approach Oliver about it and allow him to do his job.
 * 20) Moira Queen: Whilst having a conversation about Thea, Moira also revealed to Oliver that she had figured that Oliver was the vigilante since around the events of The Undertaking, and before Oliver could say a thing, Moira expressed that she couldn't be prouder.
 * 21) Sebastian Blood: When having dinner, Sebastian was joined by Oliver who started a conversation about Slade Wilson before saying “I'm the Arrow”. Sebastian didn't seem overly suprised at the discovery.
 * 22) Harrison Wells: After The Arrow and his team came to Central City to help The Flash and his team, Harrison wished to learn The Arrow's identity in order to put his faith in him, though Felicity reasoned that it wasn't her secret to tell. However, he was later able to simply guess who he was to Felicity.
 * 23) Joe West: Harrison was able to simply guess The Arrow's identity in front of the S.T.A.R. Labs team, Felicity confirming it as she was at the point of no return in regards to denial.
 * 24) Caitlin Snow: Harrison was able to simply guess The Arrow's identity in front of the S.T.A.R. Labs team, Felicity confirming it as she was at the point of no return in regards to denial.
 * 25) Cisco Ramon: Harrison was able to simply guess The Arrow's identity in front of the S.T.A.R. Labs team, Felicity confirming it as she was at the point of no return in regards to denial.
 * 26) Thea Queen: Oliver told Thea that he's The Arrow after Malcoln told him to tell er.

Slade Wilson/Deathstroke

 * 1) Sebastian Blood: After Sebastian failed to stop Oliver and Laurel from finding a file on his father, Slade became angry, killing multiple guards and pulling off his mask to reveal himself.
 * 2) Oliver Queen: When he went to Amanda Waller, Oliver was told about Deathstroke. He made the connection soon enough that Slade was the masked vigilante.
 * 3) Sara Lance: Although off-camera, it is presumed that Team Arrow were told about Deathstroke by Oliver.
 * 4) John Diggle: Although off-camera, it is presumed that Team Arrow were told about Deathstroke by Oliver.
 * 5) Felicity Smoak: Although off-camera, it is presumed that Team Arrow were told about Deathstroke by Oliver.
 * 6) Roy Harper: Although off-camera, it is presumed that Team Arrow were told about Deathstroke by Oliver.
 * 7) A.R.G.U.S.: The entirety of A.R.G.U.S., including the likes of Amanda Waller and Lyla Michaels, were not aware of Slade's secret identity, Deathstroke, until Oliver told Amanda that Slade is alive. After this she quickly figured out that the mercenary that they had codenamed Deathstroke is Slade.
 * 8) Isabel Rochev: As they were part of the Church of Blood together, it was presumed Isabel was aware of Slade being Deathstroke.
 * 9) Laurel Lance: In the underground Church of Blood base, it is unknown but confirmed that Laurel found out about Slade.
 * 10) Quentin Lance: After the masked man was shown on screen, The Arrow called Quentin to arrest Slade Wilson. Quentin then figured out that Slade is Deathstroke.
 * 11) League of Assassins: The entire league, including Nyssa al Ghul, are aware of Slade's secret identity; they learned this through Sara Lance.

Roy Harper/Arsenal/Red Arrow

 * 1) Oliver Queen: After Roy joined the team, he helped fight crime with him.
 * 2) John Diggle: After Roy joined the team, he helped fight crime with him.
 * 3) Felicity Smoak: After Roy joined the team, he helped fight crime with her.
 * 4) Sara Lance: After Roy joined the team, he helped fight crime with her.
 * 5) Laurel Lance: When Laurel joined Team Arrow, she discovered Roy's identity.
 * 6) Nyssa al Ghul: When Nyssa temporarily joined Team Arrow, she became aware of Roy's identity.
 * 7) Barry Allen: When he and the S.T.A.R. Labs team visited Starling City to help The Arrow, he was allowed in to the Arrowcave, becoming aware of Arsenal's identity.
 * 8) Caitlin Snow: When she and the S.T.A.R. Labs team visited Starling City to help The Arrow, she was allowed in to the Arrowcave, becoming aware of Arsenal's identity.
 * 9) Cisco Ramon: When he and the S.T.A.R. Labs team visited Starling City to help The Arrow, he was allowed in to the Arrowcave, becoming aware of Arsenal's identity.
 * 10) Thea Queen: Thea was able to deduce that Roy was the red-hooded counterpart to The Arrow.
 * 11) Quentin Lance: Quentin knows about Roy as Arsenal by wearing a red hooded jumper.

Ted Grant/Wildcat

 * 1) Oliver Queen: After Oliver got into a confrontation with Ted, the latter confess to Oliver that he used to be a vigilante.
 * 2) John Diggle: Diggle learned through Oliver that Ted is a former vigilante known as Wildcat.
 * 3) Felicity Smoak: Felicity learned through Oliver that Ted is a former vigilante known as Wildcat.
 * 4) Roy Harper: Roy learned through Oliver that Ted is a former vigilante known as Wildcat.
 * 5) Laurel Lance: Laurel learned through Oliver that Ted is a former vigilante known as Wildcat.
 * 6) Isaac Stanzler: Isaac was aware of Ted's secret identity, as he was once the letters partner and protégé.
 * 7) Starling City Police Department: All members of the Starling City Police Department, like Quentin Lance, are aware of Ted's secret identity, after they receive an anonymous tip that led them to a dead body found in Ted's locker, as well as evidence that he supposedly killed seventeen people, also revealing his past as a vigilante, however the evidences were planted there to frame him for crimes he did not commit, as the tip came from Isaac Stanzler, Ted's ex-partner and former protégé.