Batgirl is the name of several fictional characters appearing in comic books published by DC Comics, frequently depicted as female counterparts to the superhero Batman. Originally created by Bill Finger and Sheldon Moldoff, a character that is (arguably) considered by some to be the first incarnation of Batgirl, the "Bat-Girl" Betty Kane, debuted in Batman #139 (April 1961) as the Robin-like sidekick to Batwoman. Following the promotion of Julius Schwartz to editor of the Batman-related comic book titles in 1964, the Bat-Girl character was removed from publication (along with Batwoman) and replaced by the "new" Batgirl Barbara Gordon, police commissioner James Gordon's daughter, in late 1966. This version of Batgirl was introduced in Gardner Fox and Carmine Infantino's Detective Comics #359, entitled "The Million Dollar Debut of Batgirl."
Batgirl proved vastly more popular than the earlier "Bat-Girl" and made regular, in-continuity appearances in DC comics from late 1966 to 1988. The official retirement of Batgirl took place in Batgirl Special #1 (June 1988), which was published a few months after Barbara Gordon's shooting by the Joker in the graphic novel Batman: The Killing Joke (March 1988). Editor Kim Yale and comic book author John Ostrander later reinvented the discarded Barbara Gordon character as Oracle, the premier information broker of the DC Comics Universe and leader of the Birds of Prey organization. In the 1999 story Batman: No Man's Land, Helena Bertinelli (better known as Huntress) briefly assumes the role of Batgirl until she is stripped of the identity by Batman towards the conclusion of the story for violating his stringent codes. Within the same year, Cassandra Cain (created by Kelley Puckett and Damion Scott), introduced during the "No Man's Land" series, becomes the fourth Batgirl. She is mentored by Batman and Oracle. Cassandra Cain became the first version of the Batgirl character to be featured in an eponymous monthly series, which was published from 2000 to 2006, ending with Cain relinquishing her role as Batgirl. Subsequently in the pages of Teen Titans, Cassandra Cain reclaimed her former identity as Batgirl. Later still, she passes on the Batgirl alias to Stephanie Brown (previously known as Spoiler and Robin) in the first issue of Brown's own Batgirl series (October 2009). That series was canceled at 24 issues. In September 2011, DC Comics relaunched the Batgirl title with Barbara Gordon, now cured of her paralysis, in the titular role.
Batgirl has also been the title of three ongoing comic book series (as well as one comic book miniseries) published by DC Comics.