The Flash is not one, but three characters from DC Comics, and all three of them managed to make it into the series in some way. Jay Garrick, who was the first Flash and whose adventures inspired Barry Allen (the second) lives on in the name of Barry's brother, who's death inspires our hero. Barry Allen was a police scientist, but was also married to Iris West, the aunt of Wally West (the third Flash) who briefly dated Tina McGee some time after Barry died. The Flash of the television series is a combination of Barry Allen's name and day job with Wally West's social life, and a personality falling somewhere between the two.
When Christina McGee calls Barry for the first time, she tells him to come to "50, Garrick Ave". Jay Garrick was the name of the first Flash
The series is replete with references to the comic books and their creators. In addition to the "Garrick Ave." reference mentioned in another item, episodes have referenced "The Hotel Infantino" (a nod to Silver Age Flash co-creator Carmine Infantino), "police captain Julius Schwartz" (a nod to Silver Age Flash co-creator Julius Schwartz), "the intersection of Gardner and Fox" (a nod to Golden Age Flash creator Gardner Fox), "Professor Zoom" (a recurring villain in the Silver Age Flash stories) and "Gorilla Grodd" (another recurring Silver Age Flash villain).
When Jay gives the press conference, he is asked a question by a reporter who identifies herself as "Linda Park". Linda Park is the TV reporter girlfriend and later wife of Wally West, the third flash.
According to exec producers Danny Bilson and Paul De Meo in their DVD commentary, if the show was picked up for a second season, the premiere would have featured the Trickster, Captain Cold, and Mirror Master teaming-up to take on the Flash.
The show was canceled because of high production costs and a fluctuating time-slot which caused poor ratings to occur.
The role of Barry Allen/The Flash was originally written for Richard Burgi. Burgi ended up guest starring as The Deadly Nightshade in one episode.
DC Comic's Sandman was unintentionally the inspiration for the Nightshade's costume design.
The series had a hard time attracting ratings as it first aired on Thursdays at 8 against The Cosby Show and The Simpsons who were having a highly hyped ratings duel. CBS moved the series to 8:30, an unusual time slot for a hour long drama and aired a promotional campaign to remind viewers to switch over "After Bill, After Bart." The move didn't work, and the series was relegated to Saturday, and eventually in a last ditch effort to try to build interest for a possible second season was moved to Friday.
Danny Elfman composed the theme for "The Flash," as well as "Batman: The Animated Series." The music is exceptionally similar between the two shows.
Barry Allen's older brother's name is Jay. Jay Garrick was the original Flash in the comic books.
A police officer calls for backup at the "corner of Gardner and Fox", a reference to Gardner Fox, co-creator of the original Golden Age Flash.
When Tina calls her assistant over, Tina mentions Dr. Carter Hall, secret identity of Hawkman in the DC comics.
While Barry is walking his dog he passes by a theater showing a double feature of Batman and Superman.
Barry Allen refers to a journalistic "Arkham exposé". Arkham, of course, refers to Arkham Asylum, the facility later featured in many Batman films. However, this episode aired before Arkham appeared or received mention in any of the Batman TV shows or films, thus the first TV or movie reference to Arkham was in a Flash TV show, not a Batman related adaptation.
Belasco's hideout is in the abandoned "Fillmore Central" theater. An obvious reference to the iconic hippie-era venues, The Fillmore West and The Fillmore East.
Near the beginning of the episode, Barry Allen is walking his dog, Earl, past the cinema which is showing a double-feature: "Superman" and "Batman." "Batman" was released in 1989, and a series of "Superman" movies starting a decade before.
In his first public appearance as "The Trickster," James Jesse uses, as a prop, a statue of The Flash which wears the winged helmet and boots of the Golden Age Flash (a predecessor of the character on which this series is based).
In an attempt to smoke out The Trickster, Barry (The Flash) Allen issues a challenge to The Trickster to meet him for a "Clash of the Titans" at the Infantino Hotel. This is a nod to Carmine Infantino, a DC Comics artist who was the creator of the Silver Age Flash (the character on which this series is based.
At the policeman's costume ball a man can be seen wearing a Superman costume.
In making a getaway, the Black Rose Gang are reported as driving north on Keystone Drive. This is a nod to Keystone City, the home base of the original Golden Age Flash.
The Nightshade, in trying to regain the confidence of Fosnight (his former source), speaks of "...the last time I brought you down; you were short timing for Gorilla Grodd in Helltown." Gorilla Grodd is a member of the Silver Age Flash's "Rogues Gallery" in the DC Comics series on which the series is based.
Researching police files on The Nightshade, Lt. Garfield reads a confidential statement from "Police Captain Julius Schwartz." Julius Schwartz was one of the creators of the DC Comics character of the Silver Age Flash (on whom this series is based).
Stacia Masters, pumping Barry Allen for information on the Flash's origins, speculates that he was "built" by some mad scientist, who she calls "Professor Zoom". Professor Zoom (a/k/a The Reverse Flash) was one of the Golden Age Flash's classic villains in the DC Comics series. Also, this episode features another reference to "The Hotel Infantino", a reference to Golden Age Flash co-creator Carmine Infantino.
The scene in Fosnight's apartment where he asks Alpha what color underwear he has on and she correctly answers "Red," would seem to be a nod to 1978's "Superman The Movie," when Lois Lane asks Superman the same question and he gives the classic answer, "Pink."