Season 6 (The Flash: 2014)

"We've all lost so much this year. Our power, our love, our family. At times, it's even felt like there's nothing left to lose, like everything that matters has already been taken, and our lives are empty, hollow inside. Some things can't be taken. Look around this room. We still have our faith in each other and our will to fight for those we love. This is what we'll never lose. Eva McCulloch has never faced us head-on. And that's about to change. We're gonna find her, beat her, and get back everyone."

- Barry Allen's motivational speech

The sixth season of premiered on October 8, 2019, on The CW and concluded on May 12, 2020. The season consisted of 19 total episodes during its run.

Synopsis
Barry Allen lived a normal life as a perpetually tardy CSI in the Central City Police Department. He was adopted by his best friend, Iris West's father, Detective Joe West after Barry's mother was murdered. Barry's life was forever changed the night the S.T.A.R. Labs particle accelerator exploded, creating a dark-matter lightning storm that struck Barry, bestowing him with super-speed 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 Central City. Barry teamed up with his friends at S.T.A.R. Labs, Caitlin Snow, Cisco Ramon, and Dr. Harrison Wells, to begin a journey as The Flash and protect the people of Central City from these powerful new threats.

After years of battling villains and repeatedly saving Central City, Barry and his wife Iris thought they could finally find time to enjoy being newlyweds, but their wedded bliss was interrupted by the appearance of their future daughter Nora West-Allen, who is a speedster known as XS, who has made a big mistake and needs her parents' help to get home. With Nora in the picture, Barry and Iris' lives are flipped upside down and, while Nora idolizes Barry and his legacy as The Flash, she carries with her a mysterious grudge towards Iris. Team Flash rallies to find a way to help Nora return to her time, only to discover her presence has altered the timeline and brought the early arrival of the most ruthless, vicious, and relentless villain Team Flash has ever faced: Cicada. They enlist the help of Sherloque Wells to aid in the search for Cicada, while Barry teaches a stuck Nora everything he knows about being a speedster and what it means to be a hero. Nora assists Team Flash with the take-down of a surge of new "meta-humans," but her place on the team is threatened when it is revealed that she is in league with none other than one of The Flash's earliest arch-enemies, Eobard Thawne. Ultimately, Nora is innocent in the grand scheme of Thawne's plan and helps Team Flash realize a way to defeat both Cicada and Thawne – yet, vanquishing their foes yields an agonizing loss as Nora erases herself from the timeline, leaving all of Team Flash devastated.

Reeling from the loss of Nora, Barry throws himself into work, defeating a record number of metas over the summer, while the rest of Team Flash deals with changes of their own – Cisco, having taken the meta-human cure, is no longer Vibe, Joe is now Captain of C.C.P.D., D.A. Cecile Horton is now considering leaving the district attorney's office, and Ralph Dibny is now searching for a missing heiress named Sue Dearbon. But all of that is put on hold when Dr. Ramsey Rosso, intent on curing death, is overtaken by his own desperation and ambition giving birth to a new villain, Bloodwork.

Cast

 * -|Pre-Crisis Cast=

Main Cast

 * Grant Gustin as The Flash/Dark Flash (Barry Allen)
 * Candice Patton as Iris West-Allen
 * Danielle Panabaker as Frost (Caitlin Snow)
 * Carlos Valdes as Vibe (Cisco Ramon) / Echo (Cisco Ramon)
 * Hartley Sawyer as Elongated Man (Ralph Dibny)
 * Danielle Nicolet as Cecile Horton
 * LaMonica Garrett as The Monitor (Mar Novu) / Anti-Monitor (Mobius) *
 * Tom Cavanagh as Pariah (Harrison Nash Wells) / Reverse-Flash (Eobard Thawne)
 * Jesse L. Martin as Joe West

Recurring Cast

 * Sendhil Ramamurthy as Bloodwork (Ramsey Rosso)
 * Victoria Park as Kamilla Hwang
 * Brandon McKnight as Chester P. Runk
 * Ryan Handley as Godspeed
 * John Wesley Shipp as Jay Garrick / The Flash (Barry Allen)
 * Michelle Harrison as Joan Williams / Nora Allen (Speed Force)
 * Kayla Compton as Accelerant (Allegra Garcia)
 * Alexa Barajas as Ultraviolet (Esperanza Garcia)
 * Shawn Sewart as Mitch Romero
 * Mark Sweatman as Michael Norvock
 * Meera Simhan as Rachel Rosso
 * Tess Atkins as Natalie
 * Rebecca Roberts as January Galore (Sue Dearbon)

In-Universe Guest Stars

 * Jon Cryer as Lex Luthor
 * Matt Ryan as John Constantine
 * Tom Ellis as Lucifer Morningstar
 * Stephen Amell as Green Arrow (Oliver Queen)
 * Caity Lotz as White Canary (Sara Lance)
 * Brandon Routh as The Atom (Ray Palmer) / Superman/Clark Kent (Kal-El)
 * David Ramsey as John Diggle
 * Katherine McNamara as Mia Smoak
 * Elizabeth Tulloch as Lois Lane
 * David Harewood as J'onn J'onzz
 * Tyler Hoechlin as Superman/Clark Kent (Kal-El)
 * Cress Williams as Black Lightning (Jefferson Pierce)
 * Ruby Rose as Batwoman (Kate Kane)
 * Melissa Benoist as Supergirl/Kara Danvers (Kara Zor-El)
 * Ashley Scott as Huntress (Helena Kyle)
 * Audrey Marie Anderson as Harbinger (Lyla Michaels) / Anti-Monitor (Mobius)
 * Osric Chau as Ryan Choi
 * Stephen Lobo as Jim Corrigan
 * Wentworth Miller as Leonard


 * -|Post-Crisis Cast=

Main Cast

 * Grant Gustin as The Flash (Barry Allen)
 * Candice Patton as Iris West-Allen / Iris West-Allen
 * Danielle Panabaker as Frost (Caitlin Snow)
 * Carlos Valdes as Cisco Ramon
 * Hartley Sawyer as Elongated Man (Ralph Dibny)
 * Danielle Nicolet as Cecile Horton
 * Efrat Dot as Eva McCulloch *
 * Tom Cavanagh as Harrison Nash Wells / Harry Wells / Harrison Sherloque Wells / Reverse-Flash (Eobard Thawne)
 * Jesse L. Martin as Joe West / Joe West (Ralph Dibny)

Recurring Cast

 * Sendhil Ramamurthy as Bloodwork (Ramsey Rosso)
 * Victoria Park as Kamilla Hwang / Kamilla Hwang
 * Brandon McKnight as Chester P. Runk
 * Ryan Handley as Godspeed Clones
 * Michelle Harrison as Nora Allen (Speed Force)
 * Kayla Compton as Allegra Garcia
 * Alexa Barajas as Ultraviolet (Esperanza Garcia)
 * Tess Atkins as Natalie
 * Eric Nenninger as Joseph Carver
 * Emmie Nagata as Dr. Light (Kimiyo Hoshi)
 * Andrew J. Hampton as Maurice Bumblefeather
 * Stephanie Iszak as Daisy Korber
 * Natalie Dreyfuss as Sue Dearbon
 * Andy Mientus as Pied Piper (Hartley Rathaway)
 * Patrick Sabongui as David Singh / David Singh
 * Natalie Sharp as Sunshine (Millie Rawlins)

In-Universe Guest Stars

 * David Ramsey as John Diggle

Notes:
 * 1) LaMonica Garrett is only credited for his respective episode appearances.
 * 2) Efrat Dot is credited as a series regular from 5x12  onwards.

Soundtrack
On February 26, 2021, an album consisting of incidental music from the season was released digitally on Spotify and Amazon Music.

Trivia

 * Due to the 2019-2020 Coronavirus Pandemic, this season only has 19 episodes.
 * This makes this season the first one to not have 22 or more episodes as well as the shortest season of the show.
 * As is already 85% completed, the episode will air as the season premiere of the following season along with the remaining written episodes originally for this season.