When Barry is showing S.T.A.R. Labs his power, the camera pans to a billboard for Ferris Air. Ferris Air is the employer of Hal Jordan, the alter ego of Green Lantern.
Mark Hamill has played all on-screen versions of The Trickster/James Jesse including the original The Flash (1990) TV series and Justice League Unlimited (2004), as well as this one. His costume from the original series was also shown in his latest incarnation during the episode "Tricksters".
According to Secret Origins Annual #2 (1988), Barry Allen turns into a lightning bolt, goes back in time, and becomes the very same lightning bolt that struck him, splashing his past-self with chemicals and tranforming him into The Flash.
In the Arrow crossover episode, Iris states she'll start calling Flash by his name from now on, the Flash responds "like Ralph or something"? This is a quote from Superman (1978) during the rooftop terrace scene with Lois and Superman.
As a nod to The Big Bang Theory (2007), Cisco is seen occasionally wearing a 'Bazinga', a 'That's my spot' or a 'Rock/Paper/Scissors/Lizard/Spock' t-shirt in homage to Flash-loving, t-shirt wearer character, Sheldon Cooper. This creates a plot hole (of sorts) as Sheldon Cooper wears flash t-shirts and talks about the tv show.
The mural at the Central City police department features references to both the Flash and Arrow. Two figures included in the mural are Hermes (or Mercury) and Apollo. The Hermes figure wears the winged helmet that was adopted by the Golden Age version of the Flash, while Apollo is depicted as an archer, similar to Oliver Queen's Arrow.
The Flash made his comic book debut in January 1940 in Flash Comics #1. The original was a research scientist named Jay Garrick who gained his abilities by breathing in radioactive vapors. The second person, Barry Allen was introduced in October 1956 in Showcase #4. He gained his powers from a lightning strike as the show details. Jay Garrick appears in later seasons as a recurring character, the Flash from another universe.
On the poster of The Flash, in the background you can see Big Belly Burger, Barry Allen's favorite fast food restaurant and Queen Consolidated, the business Oliver Queen, also known as Green Arrow, owns.
Guest stars Wentworth Miller, Dominic Purcell and Robert Knepper were all Main Casts of Prison Break (2005).
Iron Heights Prison is the same prison used in Arrow (2012), where Moira Queen was being held.
Rainbow Raider's "real name," Roy G. Bivolo, is a reference to "ROYGBIV," which is the order of the colors of a rainbow: Red, Orange, Yellow, Green, Blue, Indigo, and Violet.
Grant Gustin, who plays The Flash/Barry Allen in this series, and John Wesley Shipp, who played The Flash/Barry Allen in the 1990 version of The Flash (1990), were both born in Norfolk, VA.
Starting from the episode, "Flash vs. Arrow", slight modifications were made to the Flash's suit, specifically the eyes and mouth, in order for the suit to resemble its comic companion.
Was renewed for Season 2 in early January 2015 (having only aired 9 episodes of 23).
Barry Allen was one of the pseudonyms used by Leonardo DiCaprio / Frank Abagnale in the film Catch Me If You Can (2002), and this led to him being finally caught in the film as most of the names he used came from comic books, as he was a minor when he started ripping off Pan-Am. In real life, Abagnale did not follow this practice.
In episode 8 of season 3 in Arrow, The Brave and the Bold, when Oliver Queen is introducing Barry Allen to Captain Lance, Lance mistakes his name as Bart Allen. In the comics, Bart Allen, who is the sidekick of the second Flash and eventually becomes the Flash himself, is Barry's grandson.
The appearance of the Barry Allen Flash is considered to mark the beginning of the "Silver Age" of comic books, leading to a revival and update of many other classic superheroes of the 30s and 40s, including Green Lantern.
One of the four new DC Comics television series which had been scheduled to come out in 2014, the others being Gotham (2014), Supergirl and Constantine (2014). Constantine was canceled after the first season and Supergirl was pushed to 2015.
King Shark and Gorilla Grodd are the only fully CGI characters showcased on the show.
Unlike the rest of the characters, Eddie Thawne (Rick Cosnett), Harrison Wells (Tom Cavanagh) and his wife Tess Morgan (Bre Blair) were created specially for the show, not being part of the DC Comics Universe previously.
When Thawne is going back to his time, he mentions Rip Hunter as the first man to build a time machine. Rip Hunter is a superhero created in 1959 by Jack Miller and Ruben Moreira, a scientific genius capable to build time machines, turning himself in a "time agent" to prevent disasters along the history. Hunter is also the main protagonist of DC's Legends of Tomorrow (2016), Arrow (2012) and The Flash (2014) spin-off about time travel.
Wally West is based on both versions with the original and his New 52 counterpart although he acts more like his New 52 counterpart in personality.
The house that Dr. Harrison Wells lives in is the same house used in The X-Files' episode "Ghost in the Machine".
Actor Vito D' Ambrosio played officer Tony Bellows in the 1990-1991 series and mayor Anthony Bellows in Season 2 of the new series.
The newspaper from the future that Dr. Wells keeps looking at during season 1 is a nod to the Crisis on Infinite Earths and spin off show Arrow (2012) and Bruce Wayne's/Batman's company Waynetech.
When you first see Barry Allen on Arrow (2012) he is carrying a magazine for the particle accelerator. The particle accelerator is what gave the flash his powers.
Eobard Thawne is the 2nd Reverse Flash, Barry Allen's archenemy in the "Silver Age" of comic books. The 1st was Edward Clariss/Flash Rival, Jay Garrick's archenemy in the Golden Age. The 3rd was Hunter Zolomon/Zoom, Wally West's archenemy, in the Bronze Age. The 4th was Thaddeus Thawne, aka Inertia and Kid Zoom, and Bart Allen's archenemy in the Modern Age. The 5th and final was Daniel West (Iris' Brother) He is the New 52 version and the only one to be known exclusively as Reverse Flash.
The effect where The Flash runs into a room and displaces air causing the other character's hair to be moved in the wind is referred to by the cast and crew as "zooping". It is achieved by Grant Gustin walking into a room and making a sudden motion to imitate deceleration while an off camera air cannon is fired at the other members of the cast to blow their hair. The red lightning special effects and sound are added in post-production.
Second time Michael Ironside and Peyton List portray father and daughter in a CW series based on DC Comics characters. They previously guest-starred as General Sam Lane and Lucy Lane in Smallville (2001).
In the episode "Killer Frost" , when Caitlin takes Julian to the warehouse a trailer is seen outside belonging to a company called "Ledded Goh". This is a play on words referencing the song "Let It Go" from the Disney movie "Frozen" in which one of the main characters has abilities similar to Caitlin.
The cowls of the Flash and the Reverse Flash can't actually be taken off easily. When a character is shown donning or removing the cowl, it's either done at super speed, or there is a reaction shot inserted between the moment they begin removing the cowl and the moment their face is revealed.
As well as The Flash (1990), Barry Allen is a brunette. In the original DC Comics he is blonde.
In the comics, Wally and Iris are nephew and aunt, in the TV series, they're brother and sister.
The actors have joked about the fact that the cast includes three actors with the first name 'Tom': Tom Cavanaugh (Dr Wells), Tom Felton (Julian) and even though he uses his middle name 'Grant', his full birth name is Thomas Grant Gustin (Barry).
This is not the first DC based project that Clancy Brown (General Wade Eiling) has been part of. Since the mid 1990's he has done the voice of Lex Luthor in several projects including Superman: The Animated Series (1996), Justice League (2001) and Justice League Unlimited (2004), Superman/Batman: Public Enemies (2009), and Lego Batman 2: DC Super Heroes & Lego Batman 3: Beyond Gotham and also as the voice of Parallax in Green Lantern (2011).
With the exception of Bart Allen, all comic book versions of the Flash appear in the TV show, although not all of them have had speed at first, but they did eventually gain it.
The episode 8 of season 2 of The Flash and episode 8 of season 4 of Arrow are both crossover episodes called Legends of Today and Legends of Yesterday respectively. Its because the episodes build up to the spin off series called Legends of Tomorrow.
Melissa Benoist who plays Kara Zor-El/Kara Danvers/Supergirl in Supergirl (2015) starred on the FOX hit show Glee (2009) which is where Grant Gustin (The Flash) got his big start as an enemy to the rival glee club New Directions.
Patrick Sabongui who plays the police captain previously played a street dealer on Arrow.
Towards the end of the first season, Snart (Captain Cold) learns of Barry's secret identity and the two call something of a truce. Originally in DC comics, Barry maintained this type of "relationship" with Snart's partner Heat Wave (Mick Rory) who had uncovered his identity.
Although the costume worn in the show is similar to the one seen in the comics, the show's suit includes a slightly different color scheme and design inputs.
Grant Gustin played a Warbler in Glee (2009) opposite Darren Criss. Darren Criss starred in Starkid, a musical theatre group with which Carlos Valdes, who plays Cisco, is also affiliated.
Liam McIntyre who plays the title role in Starz TV show Spartacus (2010), plays Mark Mardon (Weather Wizard) in The Flash. His Spartacus co-stars (Cynthia Addai-Robinson, Nick E. Tarabay, Katrina Law and Manu Bennett) all played roles as bad guys in Arrow (2012) (the show The Flash spun off from) and his co-star Todd Lasance is cast in season 3.
In 'Grodd Lives' in season 1 and 'Gorilla Warfare' in season two we see a shot of Grodd's lair - a triangular building like the Flat Iron with a high tower at the point of the triangle, described in 'Gorilla Warfare' as a bell tower. This same building features as the establishing outside shots of Watchtower - Clark Kent and his League's HQ in later seasons of Smallville (2000)
Jefferson "Jax" Jackson who was introduced as the new half of Firestorm in Season 2 (who replaces Ronnie Raymond as Martin Stein's other half), was formerly a high school football quarterback that once had a promising career with multiple scholarship offers before an injury ended that dream. This actually borrows plot elements from the New 52 origin story of both Ronnie Raymond and Cyborg aka Victor "Vic" Stone (as seen in the early issues of Justice League (2011) and The Fury of Firestorm comics and the later Secret Origins (2014) limited series). Ironically, these incidents also led to all of them becoming superheroes.
In episode 1x18, "All Star Team Up", Brandon Routh is introduced as superhero Ray Palmer/Atom. Routh is also known for his role of Superman on Superman Returns (2006), also a DC Comics' superhero.
When Barry goes back in time and saves his mom, the new timeline is called Flashpoint. Victor Garber had a recurring role in the tv series Flashpoint (not related to the storyline in "The Flash.)
Grant Gustin (Barry Allen / The Flash), Candice Patton (Iris West), & Danielle Panabaker (Dr. Caitlin Snow / Killer Frost) ) are the only actors to appear in every episode of the series.
Anthony Carrigan who plays Kyle Nimbus/The Mist on the series also plays Victor Zsasz on fellow DC show Gotham (2014).
Julian Albert's ties to Savitar is via the energy known as the Philosopher's Stone, Julian Albert portrayed by Tom Felton famously portrayed Draco Malfoy in the Harry Potter franchise to which's first story Harry Potter and the Philosopher's Stone (2001) featured such a power inducing object of mythology.
The Flash never takes off or puts on his mask from beginning to end in full view of the camera. The bottom part is always skin tight against his chin so instead of a pull back hood as the viewer is led to believe, it is a pull over his head cowl/mask.
In Season 1, The Rogues are featured in Episode 4. In all subsequent seasons, The Rogues have been featured in episode 6.
Both Candice Patton (Iris West), and Shantel Vansanten (Patty Spivot), played and interacted in One Tree Hill before their role in The Flash.
Many of the guest stars on this show had starred on Transformers Prime (2010): -Clancy Brown (General Eiling) had played the human-Decepticon hybrid Cylas. -David Sobolov (Grodd) had voiced the Decepticon Shockwave. -Michael Ironside (Lewis Snart) had voiced the Autobot Ultra Magnus. -Tony Todd (Zoom) had voiced the Decepticon Dreadwing.
When the Flash travels to earth 2 he returns a phone call to his mother. On the list of preset numbers on his phone are the names Bruce, Hal, and Diana. This is likely a nod to other DC comic heroes Batman (Bruce Wayne), The Green Lantern, (Hal Jordan), and Wonder Woman (Diana Prince).
Candice Patton appeared in a photo shoot for Essence Magazine alongside Kiersey Clemons who portrays the same character of Iris West in The Flash.
John Wesley Shipp plays Henry Allen, wrongfully convicted and sent to prison for the death of Nora Allen, who was actually murdered by The Reverse-Flash. Shipp voiced Professor Zoom/Reverse Flash in Batman: The Brave and the Bold: Requiem for a Scarlet Speedster! (2010)
The newspaper from April 2024 featured at the end of the first episode states that The Flash disappeared in a street fight between himself, Star City's the Green Arrow, the Atom and Hawk girl.
Wally West's rebellious attitude as seen in the show is based around the version of the character from the New 52 which was first seen when he was introduced in the Issue 31 of the previous Flash (2011) comic book series.
Payton List who plays Lisa Snart AKA Golden Glider also played Lucy Lane in the TV series Smallville (2001) and currently plays Poison Ivy on Gotham (2014)
Jesse L. Martin (Joe West) and Andy Mientus (Hartley Rathaway/Pied Piper) were both on Smash (2012).
'The Flash' is a part of the greater 'Arrowverse'. Robbie Amell (Ronnie Raymond) has been married to Italia Ricci, who plays Siobhan Smythe on Supergirl, since October 15, 2016.
Whenever Reverse-Flash comes on screen specific music plays, the first time this happens is on episode 1X9, 'The Man in the Yellow Suit.'
In Season 5 Nora West-Allen, AKA XS being from the future uses the phrase "Schway" invented in another DC property Batman Beyond which also took place in the future. That show used the word to mean "Cool" or "Awesome".
Through Barry and Iris are parents to Nora, Jessica Parker Kennedy is 4 years older than her TV mother Candice Patton and is 6 years older than her TV father Grant Gustin.
Live-action debut of DC Comics character Ralph Diby, the Elongated Man. His debut in the comics in "The Flash" #112, Volume 1.
Jesse L. Martin's character Joe West has only rode with a partner, Eddie Thawne (Rick Cosnett) in the first season of the Flash. In all subsequent seasons, Joe West has not had a partner.
In the "new 52" comics, Iris West has a brother, Daniël, who becomes the new reverse flash. He had a train accident during a black matter outburst, wich caused that the debris of the crashed train closed around his body forming the new black and red suit and giving him the power to turn back time and run at super speeds, the downside is that the powers corrupted him. Unfortunately he has not yet appeared in the series.
YAll of the season one Legends appear on The Flash at some point, minus Sara Lance and Rip Hunter (However he is mentioned). Ray Palmer (The Atom) appears in the episode All-Star team up. Leonard Snart/Mick Rory appear as recurring season one and two villains. Kendra and Carter appear in the season two crossover Legends of Yesterday/Today Professor Stein appears in season one and four episodes of season two. Jefferson Jackson appears in The Fury of Firestorm. Sara Lance did appear in seasons three and four crossover team up episodes "Invasion!" and "Crisis on Earth-X". Rip Hunter was mentioned in the season one finale episode "Fast Enough".