The New Batman Adventures (often shortened as TNBA) is an American animated superhero television series based on the DC Comics superhero Batman, which aired on Kids' WB from September 13, 1997 to January 16, 1999. Produced by Warner Bros. Television Animation, it is a continuation of Batman: The Animated Series (1992–1995) and the third series in the DC Animated Universe. It was followed by Batman Beyond (1999–2001). The series was revamped from BTAS, replacing its art style with streamlined designs to allow for more consistent animation and maintain similarity with the simultaneously running Superman: The Animated Series (1996–2000), with episodes airing on Kids' WB under the title The New Batman/Superman Adventures.

Stories in this series tend to give more focus to Batman's supporting characters, which include fellow crimefighters Robin, Nightwing and Batgirl, among others. The show also features guest characters such as Supergirl, Etrigan the Demon and The Creeper, characters who would later appear with Batman in Justice League and Justice League Unlimited. The 2001 video game Batman: Vengeance and its 2003 follow-up Batman: Rise of Sin Tzu are based on this series.

The New Batman Adventures premiered on Kids' WB two years after Batman: The Animated Series ended its original run on Fox Kids. While working on Superman: The Animated Series, the network approached the creative team asking them if they could do more episodes of Batman, which would air alongside Superman. To freshen the look of the new show, the art style was revamped from Batman: The Animated Series for more consistent and fluid animation, as well as to keep similarity with Superman: The Animated Series. The show also had a significant change in focus from the original series, with episodes focusing less on Batman and more on the many characters that inhabited Gotham City.

Batman was given a sleeker, brawnier appearance with an overall darker costume: the yellow ellipse surrounding the bat emblem on his chest and the blue highlights of his cape and cowl were both removed and his utility belt has pouches instead of capsules and is now light brown instead of yellow, which resembles his appearance in Batman: Year One. His gadgets and vehicles were given a sleeker, redesigned look with a dark color scheme. Bruce Wayne's appearance was also changed from the previous series: his hair was brushed back to highlight his face, with blue eyes instead of black, and his regular business suit was changed from brown to black. Kevin Conroy's voice for Batman became more stern, as well as less distinguishable from his voice for Bruce than in the original series. The writers made an effort to keep Batman's dialogue terse and grim to heighten the contrast between him and the lighthearted supporting cast; this also highlighted his character change from the original series.

Batgirl's costume was changed to a look similar to her original outfit from her comic debut in Detective Comics #359 and in her appearance in the Silver Age of comics, which is now a black bodysuit with yellow gloves and boots, but keeps her blue cape and cowl and yellow bat-symbol and utility belt. Her father Commissioner Gordon's appearance was also altered, with a more slender build and a flat-top hairstyle. Producer Paul Dini said that Batgirl would appear in every episode of the new series because "Kenner wants to do a line of toys, we're taking advantage of the publicity from her being in Batman & Robin, and we just love Batgirl". In addition, Melissa Gilbert was recast with Tara Strong (credited under her maiden name Tara Charendoff) as the voice of Batgirl, as the creative team wanted a younger-sounding voice. While Batgirl did not appear in every episode, she did appear more often than Batman's other partners in the series. She also was Batman's main partner in the series rather than Robin, which differs the series from most Batman television series and in the comics (as Robin is usually Batman's main partner). Unlike the Animated Series, in this iteration Batgirl is from the outset now aware of Batman, Robin and Nightwing’s identities, and they of hers. A flashback sequence in Episode 18, "Old Wounds", explains how this came about.

Tim Drake was introduced as the new Robin in the episode "Sins of the Father". However, Dini remarked that "the Tim Drake origin in the comics as written now didn't work for us with him having a father and living so close to Wayne Manor. It seemed to work fine in the comics, but we needed our own little family unit of Batman, Robin, Batgirl and occasionally Nightwing – and Alfred of course". For these reasons, the production team came up with their own origin for Tim Drake, though they later realized this new origin was extremely similar to Jason Todd. Dini and Timm later revealed that the new Robin was always intended to have Jason's origin story and characteristics of both Jason and Tim. The decision to implement some of Todd's characteristics on Drake came up after Timm and Dini decided to not adapt the violent "Batman: A Death in the Family" comic book storyline for the show. Batman made a new suit which is similar to the first one worn by Dick Grayson and identical to Tim Drake's original Robin costume from the comics, but the color scheme was simplified to red, black and yellow, eliminating green entirely. The costume retained the familiar red short-sleeved shirt, as well as the black cape with yellow inner lining. New elements included black sleeves, gloves, trunks and boots with red leggings. The familiar domino mask had also changed, giving the new Robin a more wide-eyed, innocent look. The color scheme would later appear as Tim Drake's Robin costume in the post-Infinite Crisis comics, while the original costume worn by Dick Grayson was seen in the episodes "Old Wounds" and "Over the Edge".

Dick Grayson, having abandoned his Robin persona as a result of a falling out with Batman, adopted the identity of Nightwing. Grayson's build became sleeker, with broader shoulders, showcasing his emergence as a mature hero in his own right. The short spiky hair that Grayson wore as Robin had grown longer, styled to flow down the back of the neck. In his civilian guise, he wore it in a ponytail. As Nightwing, he wore a V-shaped mask and an all-black unitard with light blue hawk emblem that borrowed some elements of the comics version from the 1990s. The costume also featured collapsible wings under the arms that allowed Nightwing to glide for short distances.

The designs of most of the villains from Batman's rogues' gallery were also redesigned, some more so than others. The Joker was redesigned to have white eyes with black sclera and a purple and green suit. However, this was not well-received by fans, and this led to him being redesigned again for Batman Beyond: Return of the Joker (2000), Static Shock (2002) and Justice League (2002–04), where his appearance was a mix of his look from the original series and this one.