Oliver Queen is a rich playboy who was considered dead after his father's ship, the Gambit, sank. He spent four years trapped on the island Lian Yu, where he learned to fight, and also spent time in Hong Kong and Russia before he returned home to Star City. There, he became the vigilante known as the Hood and used lethal force against people his father had listed as failing Star City. After the death of his friend Tommy Merlyn, Oliver vowed to never kill again and renamed himself the Arrow. But when Star City later turned on the Arrow, Oliver faked the Arrow's death and attempted to retire from the vigilante life. However, he was brought back into the fold when H.I.V.E. waged war on the city. Oliver rebranded himself as the Green Arrow and took up the job of protecting the city once more. Now, he juggles his Green Arrow duties with being the Mayor of Star City. He has been romantically linked to Sara Lance and Laurel Lance, and was briefly engaged to Felicity Smoak.
Felicity Smoak, also known as Overwatch, is the former CEO of Palmer Technologies and a key member of Team Arrow. She met Oliver Queen when she was working in the IT department of Queen Consolidated where she unknowingly helped him as he began his vigilante operation. She eventually discovered his secret and officially coined the term Team Arrow for the group of people that help Oliver protect Star City. Felicity is the tech genius on the team and typically uses her computer skills to help them remotely. Felicity and Oliver eventually fell in love and got engaged, but they broke up when Felicity discovered Oliver had been lying to her about having a son. She was also romantically linked to Ray Palmer before he joined the Legends team.
John Diggle is Oliver Queen's best friend and a member of Team Arrow known as Spartan. He's a former bodyguard and an ex-soldier, making him great at combat and field strategy when Oliver gets in trouble. Diggle is married to Lyla and they have a baby daughter named Sara, named after Sara Lance. However, after Barry Allen created the alternate timeline Flashpoint, Diggle and Lyla's child is now a son named John Diggle Jr. After helping to defeat Damien Darhk, Diggle reenlisted in the military, and was framed for stealing a bomb. Lyla and Oliver rescued Diggle from military prison and have hidden him in Star City.
Thea Queen is Oliver's half-sister and the daughter of Malcolm Merlyn. She went by the name Speedy on Team Arrow, and currently works as Oliver's chief of staff in the mayor's office. She was briefly killed by Ra's al Ghul and resurrected using the Lazarus Pit, but when she woke up she was overcome with an uncontrollable bloodlust. She later decided to leave Team Arrow after she realized she couldn't stomach the violence anymore.
Quentin Lance is the father of Sara and Laurel and the former captain of the Star City police force. He was dismissed from the department for helping Damien Darhk, despite the fact he only did so to try and save Laurel's life. Quentin has had a tumultuous relationship with Oliver and the Green Arrow over the years, but he is now working as Oliver's deputy mayor. However, Quentin, a long-time alcoholic, recently relapsed and has had to take time off work to go to rehab.
Curtis Holt is a former employee of Palmer Technologies and grew very close to Felicity while she was CEO. He originally joined Team Arrow to help out with the tech side of things, but after being jumped and beaten, Curtis decided to become the vigilante Mr. Terrific - something he has kept a secret from his doting husband Paul.
Rene Ramirez is a headstrong vigilante working under Oliver Queen. Prior to joining Team Arrow, he was a Navy SEAL officer who was dishonorably discharged after attempting to beat information out of a prisoner. Due to their shared military background, Diggle becomes a mentor to Rene.
Rory Regan is a member of Team Arrow known as Ragman. He became a vigilante after his family was killed when a nuclear missile launched by Damien Darhk destroyed his hometown, Havenrock. Rory survived the blast after his father wrapped him in magical rags, which he now uses to avenge his family and fight crime.
Evelyn Sharp was a star student and gymnast until Damien Darhk chose her family to be some of his unwilling test subjects in his plan to destroy the world. When Malcolm Merlyn destroyed the facility where Evelyn and her family were being held, her parents were among the casualties. She blamed Darhk and the Green Arrow for their deaths, but idolized the Black Canary for her attempt to rescue them. After Laurel's death, Evelyn briefly imitated the Black Canary and attempted to avenge her family. She was later recruited by Oliver to join his new team of vigilantes, but is secretly working with the villain Prometheus.
Prometheus is a mysterious villain who has a vendetta against the Green Arrow. Prometheus uses a variety of weapons to kill his targets, whose names form anagrams for people on Oliver Queen's kill list from when he was the Hood. His desire to kill the Green Arrow runs so deep, Prometheus is even willing to kill anyone who attempts to kill the Arrow themselves.
Laurel was the Assistant District Attorney for Star City, and struggled with alcoholism and a pill addiction before finding her true purpose. After her sister Sara was killed by Malcolm Merlyn, Laurel decided to become the vigilante known as the Black Canary, fighting alongside Oliver and the rest of Team Arrow. She was killed by Damien Darhk, but Katie Cassidy has secured a recurring character contract across all four of the DC Universe shows, which means we have not seen the last of Laurel Lance.
Adrian Chase is a Star City prosecutor. Dissatisfied with what he can achieve through the law and what the Green Arrow is doing, Adrian has decided to take to the streets as the lethal crime-fighter Vigilante.
Anatoly Knyazev is a former KGB agent and was a prisoner on the island with Oliver Queen. During their time on Lian Yu, Anatoly and Oliver grew close and Oliver eventually rescued Anatoly from their captor, Anthony Ivo. In return, Anatoly made Oliver a captain in the Bratva, the Russian gang of which he is a leader, and vowed to help Oliver in his mission targeting Konstantin Kovar.
Konstantin Kovar is a Russian crime lord who also controls an army of government soldiers. Oliver set Kovar in his sights after fellow Lian Yu prisoner Taiana Venediktov asked Oliver to go to Russia, find her parents, and free the village of Krasnoyarsk from Kovar's control.
Barry Allen is a forensic specialist for the Central City PD. His biological mother was murdered by a speedster from the future named Eobard Thawne (Matt Letscher) and his biological father Henry (John Wesley Shipp) was sent to prison for the crime. Barry was then adopted by Joe West (Jesse L. Martin) and grew up with Joe's daughter Iris (Candice Patton). He was struck by lightening when the particle accelerator at S.T.A.R. Labs exploded, leaving him in a coma for nine months. When he woke up, he realized that he was capable of super human speed. He became The Flash and uses his super speed to protect the people of Central City from metahumans -- other people who were affected by the particle accelerator explosion and use their powers to harm innocent people.
Iris West is Barry's (Grant Gustin) adopted sister and a reporter for the Central City news. She uses her reporting skills to help Team Flash solve crimes and catch metahumans. She was previously engaged to Eddie Thawne (Rick Cosnett), her dad's parter on the CCPD, but he killed himself to save Central City from Eobard Thawne. At the end of Season 2 of The Flash, Iris admitted that she reciprocates Barry's feelings for her, but he decided that he needs some time to sort himself out before he's ready to see if they have a real romantic connection.
Caitlin Snow is a doctor and scientist at S.T.A.R. Labs and one of the original members of Team Flash. She was engaged to Ronnie Raymond (Robbie Amell) when the particle accelerator exploded and thought he died. She helps monitor Barry's vital signs and overall health as he continues work as The Flash. She also had a romantic relationship with Zoom (Teddy Sears) when he was pretending to be Jay Garrick in Season 2. Her villain alter ego is Killer Frost on Earth-2, a mirror dimension to the Flash's universe.
Cisco is a scientist and egineer at S.T.A.R. Labs. He was also an original member of Team Flash and helped design Barry's speed suit. He loves giving nicknames to the metahumans and has named most of The Flash's big villains. He was also affected by the particle accelerator explosion and now has psychic abilities when he touches an objects important to whomever Team Flash is trying to track down.
Dr. Harrison Wells is the inventor of the particle accelerator that exploded, creating Central City's metahumans and giving Barry Allen (Grant Gustin) his powers. In the first season of The Flash, Harrison's body was taken over by the evil speedster from the future Eobard Thawne (Matt Letscher) and so he died when Eobard died in the Season 1 finale. Earth-2 Harrison Wells then came to Central City to help Barry take down the evil speedster Zoom (Teddy Sears). Harry is a lot less personable than Harrison Wells, though they are both extremely gifted engineers and scientists.
Joe West is the biological father of Iris (Candice Patton) and the adopted father of Barry Allen (Grant Gustin). He is a detective for the Central City Police Department and heads up their metahuman task force. He uses his connection to the police to help Team Flash get more information on the metahumans. He also has a son Wally (Keiynan Lonsdale), who didn't know existed until Season 2 of The Flash.
Wally West is Joe West's (Keiynan Lonsdale) biological son. He came to Central City in Season 2 of The Flash after his mother died of a debilitating illness. He is obsessed with speed and fast cars. He was affected when Team Flash tried to recreate the particle accelerator explosion in Season 2, but it has yet to be seen whether he'll have the same speedster abilities as Barry. In the comic books, Wally West grows up to become Kid Flash.
Henry Allen is Barry Allen's (Grant Gustin) biological father. He served 17 years in prison for the crime of murdering his wife, though it was really Eobard Thawne (Matt Letscher) that did it. He was finally freed at the end of Season 1 when Eobard/Harrison admitted to the crime. He was murdered by Zoom (Teddy Sears) at the end of Season 2 of The Flash. Henry's Earth-2 doppleganger is the real Jay Garrick, who is The Flash in that particular dimension.
Jessie Quick is Harry's (Tom Cavanagh) daughter from Earth-2. She was brought to Earth-1 Central City after Team Flash rescued her from Zoom's (Teddy Sears) lair. She was also hit by the particle accelerator explosion recreation at the same time as Wally (Keiynan Lonsdale).
Patty Spivot was a detective on the Central City Police Department's metahuman task force with Joe (Jesse L. Martin). Patty dedicated her life to taking down metahumans after one killed her father when he was a teenager. Over time, she developed feelings for Barry (Grant Gustin) and they began dating, but his refusal to tell her his secret about being The Flash forced them to grow apart. Patty left Central City to go back to school and get her degree to become a forensic specialist like Barry.
Hunter Zolomon , a.k.a. Zoom, is a serial killer from Earth-2 who became that dimension's fastest speedster after their particle accelerator exploded. When Barry (Grant Gustin) opened up the portal between worlds at the end of Season 1, Zoom made it his mission to conquer both Earths. Barry was eventually able to defeat Zoom using speed and logic, but not before Zoom murdered Henry (John Wesley Shipp) at the end of Season 2.
Grod is a giant gorilla who developed psychic abilities after undergoing military experiments. He developed a strong connection with Caitlin Snow (Danielle Panabaker) in Season 2 before Barry (Grant Gustin) opened a portal to a different dimension and sent Grod back to Gorilla City -- which will be seen in the upcoming Season 3 of The Flash.
Julian Dorn is a new character to The Flash in Season 3. He's also a forensic specialist at the CCPD with Barry.
Rip Hunter is a former Time Master, but he broke away from them to avenge his wife and son's death at the hand of Vandal Savage. Rip formed the Legends team to kill Vandal Savange and in the process, the Legends also defeated the Time Masters. It then became their responsibility to protect the timeline. Shortly after this, Rip realized the only way to save New York City from an atomic bomb was to use his ship the Waverider to absorb the impact. Without consulting the other Legends, Rip scattered them throughout time. When they eventually reassembled, there was no trace of Rip beyond a cryptic holographic recording on the Waverider. His current whereabouts are unknown.
Ray Palmer is the former head of Palmer Technologies, which used to be known as Queen Consolidated. He used his company to build a powerful exosuit, which he wears as the vigilante the Atom. While testing out his suit, Ray accidentally shrunk himself, causing the world to think he was dead. He was eventually restored to full-size thanks to his ex-girlfriend Felicity Smoak. Ray was then recruited by time-traveler Rip Hunter to join the Legends team aboard the Waverider, a time machine and spaceship the team uses on their mission to protect the timeline.
Sara Lance is the sister of Laurel Lance and the original Canary. Sara was presumed dead after the boat she was on with Oliver, her sister's then-boyfriend, sank with her on board. She survived and eventually joined the League of Assassins before secretly returning to Star City. She was later killed by Macolm Merlyn, but resurrected a year later by Laurel in the Lazarus Pit. Sara was later recruited by Rip Hunter to join the Legends, where she took on the new moniker White Canary. After Rip's disappearance, Sara stepped up into a leadership role in the Legends team, although her quest to avenge her sister Laurel's death is often a conflict of interest with protecting the timeline. Sara is bisexual and has had romantic relationships with Oliver Queen and Nyssa al Ghul.
Professor Stein was affected by the particle accelerator explosion and the only way he could survive was to pair his consciousness with Ronnie Raymond, creating the superhero Firestorm. After Ronnie died in the anomaly that opened the void between Earth-1 and Earth-2, Team Flash paired Professor Stein with Jax. They formed the new Firestorm and were recruited to be part of Rip Hunter's Legends of Tomorrow team.
Jax was a high school football player when the particle accelerator exploded in Central City. The effects of the explosion had a latent response, but affected Jax in the same way they affected Ronnie Raymond. That made Jax a perfect fit to be Professor Stein's Firestorm partner after Ronnie died, since Jax and Stein can fuse their consciousness and fight as one. He was recruited with Stein by Rip Hunter to join the Legends of Tomorrow team, and now works to protect the timeline.
Leonard Snart started out as a petty thief, but after stealing his cold gun from S.T.A.R. Labs he turned himself into one of the most infamous villains on The Flash. However, Leonard became a hero after teaming up with Barry Allen on a few occasions and eventually joining the Legends team with his partner in crime, Heat Wave. He sacrificed himself to help the Legends destroy the Oculus, a powerful tool used by the Time Masters to maintain the true timeline. But Snart will return to life - and to his villainous ways - as a member of the Legion of Doom.
Mick Rory, aka Heat Wave, is a pyromaniac associate and the best friend of Leonard Snart. The two used to commit robberies together in Central City before being recruited by Rip Hunter to join the aboard the Waverider. Although Heat Wave was originally a villain and occasionally returns to his old habits, he has a strong code of honor and has grown close with Ray Palmer.
Dr. Nate Heywood is a historian who joins the Legends after the disappearance of Rip Hunter. After being injected with a biomolecular enhancer, Nate gained the power to turn his skin into steel, earning him the moniker Steel. His grandfather was Henry Heywood, also known as Commander Steel and member of the Justice Society. Commander Steel disappeared along with the rest of the JSA on a mission in 1956.
Amaya Jiwe is a member of the Justice Society of America who teamed up with the Legends to discover who killed the JSA leader Rex Tyler. She uses the Anansi Totem to channel the power of animals, and she shares the mantle Vixen with her granddaughter Mari McCabe.
Malcolm Merlyn is the former head of the League of Assassins and Thea Queen's biological father. He's a former businessman whose wife's death during a mugging inspired him to destroy a low-income neighborhood of Star City, accidentally killing his son Tommy in the process. Although he's often worked with Team Arrow, Malcolm is generally considered the Green Arrow's archenemy. Malcolm will continue indulging his dark side on Legends of Tomorrow as a member of the Legion of Doom, a new group of supervillains.
Damien Darhk is the former leader of H.I.V.E., an organization he founded after leaving the League of Assassins. He planned to destroy humanity, except for a few chosen people selected to survive the apocalypse. He used his immense magic to defeat Team Arrow at every turn, even killing Laurel Lance to get revenge on Quentin for going to them for help. He was killed by Oliver Queen, but returned in Legends of Tomorrow where he teamed up with Eobard Thawne.
Eobard Thawne is the Reverse-Flash, a speedster from the future who traveled back in time and killed Barry Allen's mom. In order to return to his own time, Thawne took over the body of Harrison Wells so that he could build the particle accelerator and train Barry. His plan was discovered by Team Flash and Thawne was erased from existence when Eddie Thawne, his ancestor, killed himself. However, Thawne was preserved by the Speed Force as a time remnant and at some point in Thawne's life, he partnered with Damien Darhk Doom to change their destinies.
Kara Zor-El is Superman's older cousin who was sent from Krypton to protect a baby Clark Kent when he got to Earth, but her pod got stuck in the Phantom Zone and by the time she arrived on Earth, Superman was already a full grown man and superhero. So, Kara grew up as Kara Danvers and became an assistant at CatCo Media until her adopted sister Alex's plane almost crashed, and Kara revealed her powers to the world as she went to save her sibling. Now Kara splits her time between being Cat Grant's (Calista Flockhart) assistant during the day, and saving the people of National City as Supergirl by night.
Alex Danvers is Kara's adopted older sister. She is a high-ranking officer in the DEO -- a secret government agency that tracks down the aliens that escaped Fort Rozz, the alien prison Kara accidentally brought to Earth with her gravitational pull when her pod was freed from the Phantom Zone. Alex is a human, but has spent her life helping to track down aliens who mean National City and Earth harm.
James Olsen, better known to comic book fans as Jimmy, is a photographer who used to work in Metropolis with Superman. Kara's famous cousin sent him to National City after Kara revealed her powers to the world to help her in her superhero transition. James has done more than help, though. He fell for Kara as they worked together and the two of them shared their first real kiss in the Season 1 finale.
Winn is Kara's best friend and co-worker. He is the first person outside of her family that she told about her powers. He's also been in love with her for years, but has had to settle for being her side kick. He's also the son of Toyman, an evil mastermind who plants bombs in children's toys. Winn is the tech guru of Team Supergirl, and really impressed the DEO on a few occasions in Season 1 when he was able to use their computer systems to help track down dangerous targets.
Hank Henshaw ran the DEO, until he revealed that the real Hank Henshaw was dead and the man that's been running the government agency is actually J'onn J'onzz -- the last surviving green alien of mars. Hank/J'onn has developed a father figure relationship with both Alex and Kara as they've started work at the DEO and works closely with Supergirl to eliminate dangerous alien threats. At the end of Season 1, he was on the run from the government which wants to take him to Project Cadmus for experimentation.
Cat Grant is the head of CatCo Media and Kara's boss. She's as smart as she is tough and delivers the best one-liners in any given episode of the show. She has two sons: her eldest Adam, whom she gave up for adoption when she was just beginning her career, and a younger son Carter who still lives with her. She is the one that coined the name Supergirl and is very keen on protecting Supergirl's hero brand. Though she's had her suspicions, she has not confirmed whether she knows Kara is Supergirl or not.
Maxwell Lord is a billionaire tech guru who doesn't trust the aliens that have revealed themselves on Earth. He is constantly trying to prepare for the day when Superman or Supergirl could turn on human kind, but it was only by working with Supergirl that he was able to help defeat Non from taking over National City and the rest of the world. He had a brief flirtation with Kara's sister Alex, but it remains to be seen if they had real feelings for each other or were manipulating each other for their own goals.
Adam Foster is Cat's eldest son, whom she gave up for adoption when she was in her early 20s. Kara helped Cat establish a new relationship with her son and subsequently Kara and Adam formed a romantic connection. However, Kara's superhero duties got in the way of her feeling like she could have a real romance with someone, and she broke up with Adam to keep him safe from her potential enemies.
Lucy Lane is the younger sister of Lois Lane and came to National City in hopes of getting out of her sister's shadow. She is the ex-girlfriend of James Olsen. She left the photographer once she discovered that he has deeper feelings for Kara than she realized. Her father is General Lane, an anti-alien military general that doesn't trust anything happening at the DEO. However, after Hank/J'onn's disappearance in Season 1, Lucy was made head of the alien catching organization.
General Lane is the father of Lois and Lucy Lane. He is a military general that sees every alien on Earth as a potential threat. Over time, he has learned to trust Kara/Supergirl, but he is still responsible for sending many aliens to Project Cadmus, a secret operation that performs experiments on the aliens that are captured by the government.
Jeremiah Danvers is Kara's adopted and Alex's biological father. He was recruited by the DEO when Kara was caught using her powers at age 12. He negotiated coming to work for the DEO in exchange for letting her stay with the Danvers and grow up as normally as possible. He was thought to be killed in the hunt for J'onn J'onnzz but a Season 1 twist revealed that Jeremiah is still alive and has been forced to work at Project Cadmus.
Eliza Danvers is Alex's biological mother, and Kara's adopted one. She's always been very fond of Kara and put extra pressure on Alex to take care of her younger sister. She was shocked to find out last season that there's a chance her husband Jeremiah is still alive.
Astra is Kara's biological aunt and the twin sister of Kara's mother, Alura. Astra was sent to Fort Rozz by her sister after she was found guilty of attempting to deploy Myriad, a mind control program on Krypton. Astra made it to Earth and attempted to deploy Myriad there instead, thinking she'd be able to save Earth from itself. However, Astra was killed in a fight by Alex before she could kill J'onn J'onzz. Her husband Non then took over the plans for Myriad at the tail end of the season.
Non is Kara's uncle, as he was married to Astra. However, he lacked the familial attachment to Kara that Astra had. When Astra died, Non continued with the plan to deploy Myriad, the mind controlling program, over National City, which turned everyone basically into zombies. He was eventually defeated by Kara and Team Supergirl in the Season 1 finale and Myriad was disabled forever.
Superman is Kara's more famous cousin and the protector of Metropolis. He made small, non-verbal appearances in the first season of Supergirl, but will have a larger part in the early part of Season 2. He will come to National City to help Kara deal with Mon-El, the Kryptonian found in the pod outside of her apartment in the Season 1 cliffhanger. Superman and Supergirl will have very different ideas about how to be a hero and Kara will have to stand up to Superman to prove that she knows how to handle herself in her city.
In Supergirl, the world already has its first female President of the United States. She'll be played by original Wonder Woman Lynda Carter.
Snapper Carr will be coming in to manage CatCo Media in the new season and will be an even tougher boss than Kara could imagine. He'll rule the newsroom with an iron fist and Kara will have to do her best to keep up while trying to maintain her superhero secret identity.
Lena Luthor is the younger sister of Superman's arch nemesis Lex Luthor. We're not sure exactly what she plans to do in National City in Season 2, but we can be it also has to deal with escaping her brother's larger than life persona.
At the end of Season 1, a Kryptonian pod landed outside of Kara's apartment with a mystery inside. That mystery has revealed to be Mon-El, who will be played by Chris Wood. In the comic books, Mon-El is an explorer from Daxam who landed on Krypton shortly before its destruction. Superman's biological father warned him that the planet was about to explode and sent him to Earth for safety. Clark Kent gave him the name Mon-El after the explorer lands on Earth with no memory of who he is. He can speak Kryptonian and shares powers that are similar to Clark and Kara's so they assume he must be from their planet.
Maggie Sawyer is a new police officer in National City. We don't know much about her except that she is a lesbian and will become entrenched in Team Supergirl.