Season 3 (The Flash)

"My name is Barry Allen, and I am the fastest man alive. To the outside world, I'm an ordinary forensic scientist. But secretly, with the help of my friends at S.T.A.R. Labs, I fight crime and find other meta-humans like me. After defeating Zoom and saving the multiverse, I ran back in time and created the alternate timeline Flashpoint. I restored the timeline to how it was, only to find things weren't as I left them. I brought new threats to our world, and I'm the only one fast enough to stop them. I am The Flash."

- Introduction

The third season of premiered on October 4, 2016, on The CW and concluded on May 23, 2017. The season consisted of 23 total episodes during its run.

Synopsis
Until recently, 26-year-old Barry Allen (Grant Gustin) lived a normal life as a perpetually tardy C.S.I. in the Central City Police Department. He was secretly in love with his best friend, Iris West (Candice Patton), daughter of Barry's surrogate father, Detective Joe West (Jesse L. Martin). Joe adopted Barry fifteen years ago after Barry's mother was murdered and Barry's father, Henry Allen, received a life sentence for the crime – though Barry always maintained that a mysterious "Man in Yellow" was responsible. Then the S.T.A.R. Labs particle accelerator exploded, creating a dark matter lightning storm that struck Barry, bestowing him with superspeed and making him the fastest man alive. But Barry wasn't the only person who was given extraordinary abilities that night. The dark matter also created meta-humans, many of whom have wreaked havoc with their powers on the city. With the help of his scientist friends at S.T.A.R Labs, Caitlin Snow (Danielle Panabaker), Cisco Ramon (Carlos Valdes), and Dr. Harrison Wells (Tom Cavanagh), Barry began a journey as The Flash to protect the people of Central City from these powerful new threats. With this team, Barry was finally able to defeat the Man in Yellow, aka The Reverse Flash, but in their epic battle, a Singularity was ripped in space and time that threatened to destroy them all.

After successfully closing the Singularity from destroying Central City, Barry thinks he's seen the worst... but the arrival of Jay Garrick (Teddy Sears) reveals that the Singularity actually opened portals to an alternate Earth, known as Earth-2, which is being terrorized by a formidable evil speedster named Zoom. As Zoom sends an army of Earth-Two meta-humans to Earth-1 to defeat Barry, he receives unexpected assistance from the Earth-Two doppelganger of his former mentor, Harrison Wells. Meanwhile, Cisco discovers that he, too, was affected by the dark matter of the Particle Accelerator and must come to terms with his newfound powers. As Barry struggles to juggle life as a hero, he opens his heart to Patty Spivot (Shantel VanSanten), a spunky detective paired with Joe West, but realizes just how hard it is to find happiness when the lives of everyone you love are at stake. He finds some solace in the companionship of his father, Henry Allen, who was freed from a wrongful life sentence... but when Zoom kills Henry before Barry's eyes, Barry's newfound stability is shattered.

Blinded by anger, Barry unwittingly plays into Zoom's game and uncovers the evil speedster's true goal: to destroy all Earths in the multiverse. In the race of his life, Barry ultimately gets the upper hand against Zoom and defeats his nemesis. But unable to celebrate victory, Barry makes a world-shaking decision and speeds back in time to the night his mother died to stop Reverse Flash from killing her, irrevocably changing his past and redetermining his future.

Main Cast

 * Grant Gustin as The Flash (Barry Allen) / Savitar/The Flash (Barry Allen)
 * Candice Patton as Iris West / Millie Foss / H.R. Wells
 * Danielle Panabaker as Killer Frost (Caitlin Snow)
 * Carlos Valdes as Vibe (Cisco Ramon) / Pablo
 * Keiynan Lonsdale as Kid Flash (Wally West)
 * Tom Cavanagh as H.R. Wells / Harry Wells / Hells Wells / Harrison Wells / Francophone Wells / Iris West
 * Jesse L. Martin as Joe West / Digsy Foss

In-Universe Guest Stars

 * Emily Bett Rickards as Overwatch (Felicity Smoak)
 * Stephen Amell as Green Arrow (Oliver Queen)
 * Franz Drameh as Firestorm (Jefferson Jackson)
 * Victor Garber as Firestorm (Martin Stein) / Digsy Foss' Husband
 * Willa Holland as Speedy (Thea Queen)
 * Caity Lotz as White Canary (Sara Lance)
 * Dominic Purcell as Heat Wave (Mick Rory)
 * David Ramsey as Spartan (John Diggle)
 * Brandon Routh as The Atom (Ray Palmer)
 * Melissa Benoist as Supergirl/Kara Danvers (Kara Zor-El)
 * John Barrowman as Cutter Moran
 * David Harewood as Martian Manhunter (J'onn J'onzz)
 * Jeremy Jordan as Grady
 * Chris Wood as Mon-El / Tommy Moran
 * Audrey Marie Anderson as Lyla Michaels
 * Christina Brucato as Lily Stein
 * Andrea Brooks as Eve Teschmacher