Title: The Flash (season 4)
Content:  The season began airing on October 10, 2017, on The CW in the United States, and on CTV in Canada. The season concluded on May 22, 2018. Sky One acquired the rights to air the season in the UK & Ireland, airing it alongside the other Arrowverse shows. The season premiered October 17.
Title: The Flash (season 4)
Content:  The season was made available for streaming on Netflix in late May 2018, soon after the season finale aired. It was released on Blu-ray on August 28, 2018.
Title: The Flash (season 4)
Content:  Filming for the season began on July 4, 2017, in Vancouver, British Columbia, and concluded on April 21, 2018. Kevin Smith returned to direct an episode in January 2018.
Title: The Flash (season 4)
Content:  The fourth season of the American television series The Flash, which is based on the DC Comics character Barry Allen / Flash, premiered on The CW on October 10, 2017, and ran for 23 episodes until May 22, 2018. The season follows a crime scene investigator with superhuman speed who fights criminals, including others who have also gained superhuman abilities. It is set in the Arrowverse, sharing continuity with the other television series of the universe, and is a spin-off of Arrow. The season is produced by Berlanti Productions, Warner Bros. Television, and DC Entertainment, with Andrew Kreisberg and Todd Helbing serving as showrunners. The season was ordered in January 2017, and filming began that July. Grant Gustin stars as Barry, with principal cast members Candice Patton, Danielle Panabaker, Carlos Valdes, Keiynan Lonsdale, Tom Cavanagh, and Jesse L. Martin also returning from previous seasons, and are joined by Neil Sandilands. The series was renewed for a fifth season on April 2, 2018.
Title: Flashpoint (TV series)
Content:  January 21, 2011, it was announced that CBS would air 7 of the 18 episodes from Season 4, as well as the remaining 6 episodes from Season 3 not yet shown on CBS, during the summer of 2011. Due to the cancellation of CHAOS, the remaining episodes from Season 3 of Flashpoint were shown on CBS starting May 6, 2011. The remaining 11 episodes from season 4 began airing on ION Television in October of that year. Filming of season four took place between February 14 and September 15, 2011. On May 9, 2011, CTV announced that the fourth season would begin 
Title: The Flash (2014 TV series)
Content:  The complete first season was first released on Blu-ray and DVD in Region 1 on September 22, 2015, the second season on September 6, 2016, the third season on September 5, 2017, the fourth season on August 28, 2018, and the fifth season on August 27, 2019. Each season release contains additional features, which include: making-of featurettes, episode commentaries, deleted scenes, gag reels, and Comic-Con panels. The second, fourth and fifth season boxsets include the Arrowverse crossover episodes from the other connected television series, as well as commentary on those episodes. On Netflix in the United States, the first season became 
Title: The Flash (season 4)
Content:  In August 2017, series composer Blake Neely and Nathaniel Blume began to compose the music for the fourth season.
Title: The Flash (season 4)
Content:  • Britne Oldford as Shawna Baez / Peek-a-Boo • Dominic Burgess as Ramsey Deacon / Kilg%re • Sugar Lyn Beard as Rebecca Sharpe / Hazard and Clifford DeVoe / Thinker • Chelsea Kurtz as Mina Chaytan / Black Bison • Violett Beane as Jesse Chambers Wells / Jesse Quick • Danny Trejo as Josh / Breacher • Vito D'Ambrosio as Anthony Bellows • Emily Bett Rickards as Felicity Smoak • Riley Jade Berglund as Joanie • Matt Afonso as Weeper • Stephen Amell as Oliver Queen / Green Arrow and Dark Arrow • Victor Garber as Martin Stein / Firestorm • Caity Lotz as Sara Lance / White Canary • Chyler 
Title: The Flash (season 4)
Content: Grant Gustin as Barry Allen / Flash ; Candice Patton as Iris West ; Danielle Panabaker as Caitlin Snow / Killer Frost ; Carlos Valdes as Cisco Ramon / Vibe ; Keiynan Lonsdale as Wally West / Kid Flash ; Neil Sandilands as Clifford DeVoe / Thinker ; Tom Cavanagh as Harry Wells ; Jesse L. Martin as Joe West 
Title: The Flash (season 4)
Content:  In July 2017, cast from the series appeared at San Diego Comic-Con International to promote the season, where exclusive footage was shown. During the panel, a trailer for the season was shown, with James Whitbrook at io9 feeling that despite the "grim" tone, there was "some fun signs of the team coming together to protect the city without [Barry],... Sprinkle in a few wacky things, like, say a goddamn Samuroid ripped straight from the comics, and ladies and gents, you've got a good season of The Flash lined up." Ben Pearson with /Film felt seeing Iris West deal with the absence of Barry was "a nice change of pace for that character", but anticipated that "Barry [would] be back two or three episodes in at the latest." Collider's Allison Keene also noted Iris "getting an actual storyline" with Barry gone, and similarly presumed that he "[would] be back in the fold by the end of the first episode" alike to Flashpoint in the third season. She added, "There are some new foes, lots of action, plenty of tech — it's great!"

Question: when is season 4 of flash coming out?
Answer: October 10, 2017.
on October 10, 2017.