Kevin Conroy is the first person in animation to use two distinct voices to portray Bruce Wayne and Batman. It was his own idea.

Tim Curry was initially cast as the voice of the Joker. After he recorded four episodes, his take on the role was deemed to be too scary, so the decision was made to re-cast, and eventually the role went to Mark Hamill.

When establishing Two-Face, the writers took the time to first show his alter-ego, Harvey Dent, in several episodes, so the audience could get to know him better. That way, they were more shocked at his transformation from the upstanding Dent to the monstrous Two-Face. The writers believed this made him into one of the show's best characters, and his origin one of the show's best episodes.

Dick Grayson, a.k.a. Robin, had to be older, because of censorship rules against showing the endangerment of children.

To create the eerie nighttime feeling, the background painters used dark paper instead of the traditional white. This also allowed them to save time from painting large portions of black color as most of the scenes are set at night. The animators coined the term "Dark Deco" for this art style.

All voice acting was, unlike most voice-over work, performed ensemble. This means that all the voice actors performed their lines in a room together, rather than at separate times in different locations. Mark Hamill was the only cast member allowed to perform his Joker voice while standing, to make it easier to infuse the character with the manic energy the role required. All the other actors did their voices sitting down.

The characters of Gotham City Police Officer Renee Montoya and Joker's girlfriend and henchwoman Dr. Harleen Frances Quinzel, a.k.a. Harley Quinn, were created for the animated series, and later incorporated into the comic books.

The title of the show is never seen. The producers decided that since Batman was an instantly recognizable character that anyone in any language would be able to tell what the show was about.

Since the debut of this series, various elements have been adapted into the regular continuity of the Batman comics. These include the series' most popular original character, Harley Quinn, and the show's origin for Mr. Freeze.

The animators auditioned over one hundred fifty actors before they settled on Kevin Conroy for the voice of Batman.

The Scarecrow's voice actor, Henry Polic II, had problems with his throat while playing Scarecrow in season one, episode thirty-one, Batman: The Animated Series: Dreams in Darkness (1992). That is why his voice in "Dreams in Darkness" is different from his voice in Batman: The Animated Series: Fear of Victory (1992) and Batman: The Animated Series: Nothing to Fear (1992). After "Dreams in Darkness", Scarecrow's appearances were reduced. Although Scarecrow appears in the episode Batman: The Animated Series: Trial (1994), he has no dialogue in this episode. This was because Polic was recuperating from throat surgery during this episode's production.

Commissioner James Gordon and Alfred Pennyworth, two of the most important characters in the Batman mythos, never exchange a word with each other throughout the entire series, even if they do appear next to each other in the same scene.

Has the most spin-offs of any animated television show ever. They include: Batman: Mask of the Phantasm (1993), Superman: The Animated Series (1996), The New Batman Adventures (1997), Batman & Mr. Freeze: SubZero (1998), Batman Beyond (1999), Static Shock (2000), Batman Beyond: Return of the Joker (2000), Justice League (2001), The Zeta Project (2001), Batman: Mystery of the Batwoman (2003), and Justice League Unlimited (2004).

The producers admitted that this series wouldn't be possible if it wasn't for Tim Burton's Batman (1989).

For a long time, the producers wanted to use Firefly, a character that uses fire as a weapon, but FOX said no completely, because they did not allow any character to be threatened or harmed by fire. It wasn't until Batman moved to the WB, that Firefly was able to be used.

Harley Quinn's relationship with The Joker was intended as a Punch and Judy coupling, but with the roles reversed. She was initially a one-shot character, but audiences took to her. She was brought back for more, and the writers even took the time to sketch a comic-book origin for Harley, to make her seem more real.

In most episodes, there is a character reading a Tiny Toon Adventures Magazine.

Harley Quinn was initially created for one episode, and was added to it almost at the last minute. In season one, episode seven, "Batman: The Animated Series: Joker's Favor (1992)", Joker was initially to disguise himself as a female model to serve as bait for a trap he was setting. Writers determined that posing as a woman would be below the Joker's ego, so they created Harley Quinn as his henchwoman for the episode to keep the disguise.

After every single storyboard, FOX would send the producers a long single-spaced list of restrictions about five pages in length, on things they could not do, for example: no child endangerment, no open wounds, no blood, no heavy gun violence, no strangling or neck grabs, no alcohol references, and no smoking. The FOX network was really picky, not just about the censorship, but just in terms of content and story. The network had many opinions on what the producers should and shouldn't be doing. Nobody bothered them like that on WB (with The New Batman Adventures (1997)), where they usually got about two paragraphs of stuff they couldn't do.

One of the reasons why Tim Curry was replaced by Mark Hamill for the role of the Joker was because executives of the show felt that Curry's voice for the Joker sounded similar to his voice for Captain Hook in Peter Pan and the Pirates (1990), and his voice for Konk in The Pirates of Dark Water (1991).

The episodes Batman: The Animated Series: Heart of Steel: Part I (1992) and Batman: The Animated Series: His Silicon Soul (1992) feature a character named Dr. Carl Rossum, a robotics engineer who creates a series of human-like robots. The character's name is taken from the 1920s science fiction play "R.U.R. (Rossum's Universal Robots)" by Karel Capek, which introduced the word "robot" into the English language. In both episodes, Dr. Carl Rossum is voiced by William Sanderson, who played the Replicant Creator J.F. Sebastian in Blade Runner (1982). As a reference to this, Randa Dwayne's car has "RUR" on its license plate.

The show's first opening sequence is essentially a remake of the pilot used to sell the show to Warner Brothers. In the pilot, Batman foils a jewelry heist on a rooftop, and leaves the robbers tied up for the Police. The pilot can be seen as a special feature on Volume 1 of the DVD collection.

When it came time to bring the Penguin into the show, Batman Returns (1992) had just gone into production. Warner Brothers insisted the animated version should reflect the one in the film, but they weren't allowed to release any pictures. Bruce Timm had to draw sketches on the set of the film, and then adjust the design accordingly for the cartoon.

The FOX Network, on the false assumption that kids won't watch a kids' show unless kids are in it, soon began insisting that Robin be prominently featured in every episode. When FOX changed the title to "The Adventures of Batman and Robin" for season three, they laid down the law. No story premise was to be considered, unless it was either a Robin story, or one in which he played a key role.

Al Pacino was initially offered the role of Two-Face.

Clive Revill played Alfred in the first three episodes in production. Efrem Zimbalist Jr. was cast in the role for the remainder of the series.

A potential story involving a Catwoman and Black Canary team-up was interrupted in mid-pitch to the FOX network by their demand, "Where's Robin?" When the writers asked if they could omit Robin from just this one episode, FOX obliged by omitting the entire story.

Adam West, Roddy McDowall, Bob Hastings, Barry Dennen, Steve Franken, Michael Pataki, and Judy Strangis are the only cast members to appear in this series and Batman (1966).

Robin's costume was modeled after Neal Adams's redesigned Robin costume that Tim Drake wore in the comics, though the Robin symbol was changed to a regular non-italicized "R", to make sure people would know he's Dick Grayson. However, when Tim Drake was used (in The New Batman Adventures (1997)), his costume was redesigned with a red, yellow, and black color scheme.

Alex Toth's Space Ghost design for Space Ghost (1966) had a big influence on Bruce Timm's final design for Batman.

Sir Anthony Hopkins was offered the role of Mr. Freeze.

Kevin Conroy auditioned for the voice of G.C.P.D. Detective Harvey Bullock.

When the series moved to Sunday evenings on FOX, it marked one of the first times an animated series created specifically as a Saturday morning cartoon had aired on primetime.

Although Batman: The Animated Series: On Leather Wings (1992) is considered as the first episode, the first episode that was aired on television, and received the attention of the audience was Batman: The Animated Series: The Cat and the Claw Part I (1992).

This series debuted only three months after the release of Batman Returns (1992). It borrowed several elements from the Tim Burton films, including: Jack Napier as the name of the Joker's alter ego, the look of the Penguin, the Penguin's duck vehicle, Danny Elfman's theme, and the design of Gotham City as a clash of styles and trends (for example, modern technology but retro clothing).

In terms of overall tone and style, this series is principally based on the very-late '60s and 1970s Batman comics, which returned to the "grim avenger of the night" approach. This era most notably took off from contributions by writer Denny O'Neil and artist Neal Adams, who brought back the style from the first year of Detective Comics Batman stories with a more realistic approach. Robin's role was significantly reduced, with Dick Grayson attending college, just like this animated series. In fact, a number of episodes in this series are direct adaptations of acclaimed Batman comics from the 1970s, and one episode was actually written by O'Neil.

Original scripts of episodes Batman: The Animated Series: Christmas with the Joker (1992), Batman: The Animated Series: The Underdwellers (1992), and Batman: The Animated Series: P.O.V. (1992) were changed due to Broadcast Standards & Practice's demands.

Michael Ansara, who voices Mister Freeze in the iconic, Emmy-winning episode Batman: The Animated Series: Heart of Ice (1992), utters the words, "Revenge is a dish best served cold." This line has been called an "Old Klingon proverb" in Star Trek (1966), where Ansara once portrayed Klingon Commander Kang. He even threatened the Enterprise crew with the line, "You will die in the icy cold of space."

After fourteen years, The Dark Knight's First Night (1992), the rarely-seen pilot promo reel developed for Warner Brothers by Bruce Timm and Eric Radomski, was included on the first DVD boxed set. Versions of the promo had surfaced in degraded bootleg form at comic conventions over the years, but it was never intended for public viewing. Unfortunately, the actual Warner Brothers reel was not kept in the best condition either, appearing at around one minute and forty-five seconds in length, and having been converted from VHS. The original audio track was lost over time, and replaced with the show's main theme for the DVD.

Roddy McDowall, who voiced The Mad Hatter, had earlier played the villain Bookworm on Batman (1966). McDowell also read the Book on Tape adaption of Batman (1989).

Paul Dini has said that Harley Quinn was partly inspired by seeing Arleen Sorkin wearing a harlequin's costume in her role as Calliope Jones on an episode of Days of Our Lives (1965). As a result, Dini was subsequently inspired to cast Sorkin as the voice of Harley Quinn. In addition, Dini and Sorkin were college classmates together.

John Glover, who voiced the Riddler, later played Dr. Jason Woodrue in Batman & Robin (1997), and then went on to play Lex Luthor's father Lionel, in Smallville (2001).

Clayface, in this series, is Matt Hagen, but instead of being a treasure hunter, he's an actor, which is the occupational background of Basil Karlo, the original character to use the name Clayface in the comics.

Mark Hamill auditioned for the role of The Joker thinking he wouldn't get the part because fans of his role of Luke Skywalker in the Star Wars movies, an icon of heroism and virtue, would be against him playing a villain like The Joker. Because he didn't think he'd get the part, he was very calm in his audition and got the part anyway.

While the Tim Burton Batman movies influenced much of the show, an updated Batman animated series had been in development for almost a decade prior to the show's debut. One proposed pilot came to be adapted as an episode of The Super Powers Team: Galactic Guardians (1985). It was largely the success of Burton's Batman (1989) which inspired the green-lighting and subsequent launch of the series.

In Batman: The Animated Series: Prophecy of Doom (1992), as Batman fights in Nostromo's observatory, the music is based upon, or a direct homage to, Gustav Holst's symphonic piece "Mars" from "The Planets".

The 1992-1995 time period of Batman is also known as the "Radomski Era", because of director and producer Eric Radomski's involvement with this show and Batman: Mask of the Phantasm (1993). According to the HBO First Look (1992) documentary "Behind the Mask: The Making of 'Batman: Mask of the Phantasm'" (1993), it was Radomski who started using black papers, opposed to traditional white papers.

Originally, Shirley Walker's Batman theme was going to be the theme music for the show, because Danny Elfman didn't want his Batman theme used for a cartoon. However, Elfman changed his mind once he learned the show would debut in primetime. Walker's Batman theme became the DC Animated Universe's Batman's music, and was eventually used as the show's theme in the last twenty FOX shows, when the title was changed to "The Adventures of Batman & Robin".

Mark Hamill got the role of The Joker largely because of the trademark laugh he created.

In the episode Batman: The Animated Series: Beware the Gray Ghost (1992), live-action Batman (1966) star Adam West provides the voice of The Grey Ghost.

Max Shreck from Batman Returns (1992) was originally intended to appear in this series, but his inclusion was scrapped, and the character of Roland Daggett was created instead.

While working in this show, Bruce Timm and story editor Sean Catherine Derek strongly disagreed with each other. According to the book "Batman: Animated" page twelve, Derek felt that directors and storyboard artists of this show were taking too many liberties with the scripts. Jules Dennis, Richard Mueller, and Derek wrote the original script of Batman: The Animated Series: The Forgotten (1992), but Timm made several changes to the script. According to Animato Magazine Issue #26, Timm put in the dream sequence with Bruce Wayne in the barracks, where multitudes of people are looking to Bruce for a hand-out, and he doesn't have enough money for them all, and they're surrounding him and suffocating him. Timm also completely changed the villain in the script, to a fat and revolting character who constantly eats.

In the show, Arkham Asylum makes its first appearance in Batman: The Animated Series: Christmas with the Joker (1992). Coincidentally, by looking closely, Mark Hamill (Joker) has the word "Arkham" hidden in his name (mARK HAMill).

In the episode Batman: The Animated Series: Trial (1994), The Riddler has no lines, but is seen presiding on the Arkham jury. When the episode returns, and Mad Hatter is about to announce the verdict, Riddler has vanished. Interestingly, though, when Batman and Janet Van Dorn attempt to escape the Asylum, Riddler's theme from his debut in Batman: The Animated Series: If You're So Smart, Why Aren't You Rich? (1992) can be heard when Two-Face and the inmates corner Batman and Janet. This may imply that the Riddler predicted Batman would escape, and left the proceeding early to be able to orchestrate a riot to stop Batman should he be able to escape. Seeing how strategic Edward Nygma can be, this is not unlikely of Riddler. It can be inferred that Riddler was apprehended when the G.C.P.D. stormed Arkham Asylum.

Andrea Romano had originally wanted Christopher Lee for the role of Ra's Al Ghul. However, she said it would have been too difficult to have him play a recurring role due to him living in England. They then thought of casting Michael York, who ended up playing another character called Vertigo. The role eventually went to David Warner, whom Romano is a fan of.

At no point in any of the episodes is the title, "Batman: The Animated Series", displayed. However, in episodes from latter seasons, the re-branded title "The Adventures of Batman & Robin" is displayed.

Debated was the inspiration for The Joker: in the original comic book, The Joker was almost identical in appearance to the main character in The Man Who Laughs (1928). Almost all episodes featuring The Joker are taken from the film.

Tim Curry was originally cast as the Joker, before he was replaced by Mark Hamill. Both would later go on to play villains on Criminal Minds (2005): Curry as Billy Flynn, a.k.a. The Prince of Darkness, and Hamill as John Curtis, a.k.a. the Replicator. Ironically, three of the main cast from "Criminal Minds" would go on to play iconic villain and hero characters, with Matthew Gray Gubler and Thomas Gibson playing villains The Riddler and Deathstroke in the animated movies Batman: Assault on Arkham (2014) and Son of BatmanSon of Batman (2014), respectively, and Shemar Moore playing the hero Cyborg in the animated movie Justice League: War (2014) (and various sequels).

Sean Catherine Derek was the first story editor hired by producers Bruce Timm and Eric Radomski for this show, but many of the episodes Derek worked on were re-written against her wishes.

In Stu Hamilton's World's Finest interview with Alan Burnett (one of the producers of this show), Burnett reveals that he is a big Alfred Hitchcock fan. He was able to get John Vernon to play Rupert Thorne on this show. Roscoe Lee Browne was also cast for the role of Dr. Wakati in the episode Batman: The Animated Series: Time Out of Joint (1994). In Hitchcock's Topaz (1969), John Vernon plays Rico Parra, and Browne plays Philippe Dubois. (Tippi Hedren, from Hitchcock's The Birds (1963) and Marnie (1964), was later cast as Donna Day in The New Batman Adventures: Mean Seasons (1998), from this show's revamped successor series, also produced by Burnett.)

Cryptozoic created a poker game based on the episode Batman: The Animated Series: Almost Got 'im (1992).

Cast members Efrem Zimbalist Jr. and Bob Hastings died less than two months apart from each other. Zimbalist died on May 2, 2014, and Hastings died on June 30, 2014.

Mark Hamill (The Joker) is famous for portraying Luke Skywalker in the Star Wars films. Billy Dee Williams, who played Lando Calrissian in those films, portrayed Harvey Dent in Batman (1989). Star Wars: Episode III - Revenge of the Sith (2005) was released the same year as Batman Begins (2005), and Star Wars: The Last Jedi (2017) was released the same year as Justice League (2017), in which Ben Affleck plays Bruce Wayne/Batman.

Tim Curry, who was originally cast as the voice of The Joker, had played a clown before: the evil clown Pennywise in It (1990).

There are two characters who share the same first name: Harvey Dent and Harvey Bullock. Harvey Dent is the former District Attorney of Gotham City who becomes Two-Face when half his face is left disfigured, and Detective Harvey Bullock is a gruff, tough Gotham cop who works under Commissioner Gordon and does not trust or like Batman and opposes him.

Although many of the episodes Sean Catherine Derek worked on were rewritten against her wishes, her idea of applying the emotions of Batman and other characters during their investigations did end up in the final versions of many episodes. Episodes like Batman: The Animated Series: The Forgotten (1992) ("my family" flashback), Batman: The Animated Series: The Underdwellers (1992) (Batman taking Sewer King's cruelty towards the children personally, which is revealed through Batman's last line to Sewer King), Batman: The Animated Series: The Cat and the Claw Part I (1992) and Batman: The Animated Series: The Cat and the Claw Part II (1992) (Bruce Wayne's romantic feelings towards Selina Kyle), Batman: The Animated Series: Cat Scratch Fever (1992) (Batman's desperate run to save Selina from the fever), and Batman: The Animated Series: Nothing to Fear (1992) (Bruce Wayne putting flowers at his parents' grave) are some examples. But the inner feelings of Montoya, Bullock, and Wilkes in the original story didn't end up in the final version of Batman: The Animated Series: P.O.V. (1992).