Season 1 (The Flash)

The first season of The Flash premiered on October 7, 2014 on The CW and concluded on May 19, 2015. The season consisted of 23 episodes. It took place in conjunction with the third season of Arrow and the first season of Constantine.

Synopsis
Barry Allen was 11 years old when his mother was killed in a bizarre and terrifying incident and his father was falsely convicted of the murder. With his life changed forever by the tragedy, Barry was taken in and raised by Detective Joe West, the father of Barry’s best friend, Iris. Now, Barry has become a brilliant, driven and endearingly geeky CSI investigator, whose determination to uncover the truth about his mother’s strange death leads him to follow up on every unexplained urban legend and scientific advancement that comes along. Barry’s latest obsession is a cutting edge particle accelerator, created by visionary physicist Harrison Wells and his S.T.A.R. Labs team, who claim that this invention will bring about unimaginable advancements in power and medicine. However, something goes horribly wrong during the public unveiling, and when the devastating explosion causes a freak storm, many lives are lost and Barry is struck by lightning. After nine months in a coma, Barry awakens to find his life has changed once again - the accident has given him the power of super speed, granting him the ability to move through Central City like an unseen guardian angel. Though initially excited by his newfound powers, Barry is shocked to discover he is not the only "meta-human" who was created in the wake of the accelerator explosion - and not everyone is using their new powers for good. In the months since the accident, the city has seen a sharp increase in missing people, unexplained deaths and other strange phenomena. Barry now has a renewed purpose - using his gift of speed to protect the innocent, while never giving up on his quest to solve his mother’s murder and clear his father’s name. For now, only a few close friends and associates know that Barry is literally the fastest man alive, but it won’t be long before the world learns what Barry Allen has become, The Flash.

Main cast
*Candice Patton as Iris West and Hannibal Bates/Everyman
 * Grant Gustin as Barry Allen/The Flash and Hannibal Bates/Everyman
 * Danielle Panabaker as Dr. Caitlin Snow and Hannibal Bates/Everyman
 * Rick Cosnett as Detective Eddie Thawne and Hannibal Bates/Everyman
 * Carlos Valdes as Cisco Ramon
 * Tom Cavanagh as Professor Eobard Thawne/Reverse-Flash, Dr. Harrison Wells and Hannibal Bates/Everyman
 * Jesse L. Martin as Detective Joe West

Recurring cast

 * John Wesley Shipp as Dr. Henry Allen
 * Michelle Harrison as Nora Allen
 * Malese Jow as Linda Park
 * Chad Rook as Clyde Mardon
 * Patrick Sabongui as Captain David Singh
 * Stephen Amell as Oliver Queen/The Arrow
 * Robbie Amell as Ronnie Raymond/Firestorm
 * Anthony Carrigan as Kyle Nimbus/The Mist
 * Wentworth Miller as Leonard Snart/Captain Cold
 * Emily Bett Rickards as Felicity Smoak
 * Clancy Brown as General Wade Eiling
 * Greg Finley as Tony Woodward Girder
 * Paul Anthony as Roy G. Bivolo/Rainbow Raider
 * Victor Garber as Professor Martin Stein/Firestorm
 * Amanda Pays as Dr. Tina McGee
 * Dominic Purcell as Mick Rory/Heat Wave
 * Peyton List as Lisa Snart/Golden Glider
 * Roger Howarth as Mason Bridge
 * Andy Mientus as Hartley Rathaway/Pied Piper
 * Britne Oldford as Shawna Baez/Peek-a-Boo
 * Liam McIntyre as Mark Mardon/Weather Wizard
 * Matt Letscher as Professor Eobard Thawne/Reverse-Flash
 * Danielle Nicolet as District Attorney Cecille Horton

Home media release
A boxset of the first season, titled The Flash: The Complete First Season, was released on DVD and Blu-ray on September 22, 2015. It contains additional features, deleted scenes, a gag reel, audio commentaries and the "A Night of DC Entertainment" panel from the San Diego Comic-Con International 2014.