Katherine "Kathy" Kane is a character appearing in American comic books published by DC Comics. She is the first DC character to appear as the superheroine Batwoman. She was created by writer Edmond Hamilton and artist Sheldon Moldoff under the direction of editor Jack Schiff, as part of an ongoing effort to expand Batman's cast of supporting characters. Batwoman began appearing in DC Comics stories beginning with Detective Comics #233 (1956), in which she was introduced as a love interest for Batman in order to combat the allegations of Batman's homosexuality arising from the controversial book Seduction of the Innocent (1954). When Julius Schwartz became editor of the Batman-related comic in 1964, he removed characters deemed non-essential, including Batwoman, Bat-Girl, Bat-Mite, and Ace the Bat-Hound. Later, the 1985 limited series Crisis on Infinite Earths retroactively established that Kathy Kane never becomes Batwoman in DC's main continuity. The character has since made appearances in the main continuity without the Batwoman persona.

Kathy Kane is primarily associated with the Silver Age of Comic Books. In the aftermath of the attacks on comics in the early 1950s, the Batwoman was the first of several characters that would make up the 'Batman Family'. Since the family formula had proven very successful for the Superman franchise, editor Jack Schiff suggested to Batman co-creator, Bob Kane, that he create one for the Batman. A female was chosen first, to offset the charges made by Fredric Wertham that Batman and the original Robin, Dick Grayson, were homosexual. Kathy Kane and alter ego Batwoman first appeared in Detective Comics #233 (July 1956). In the character's debut issue, Batwoman is introduced as a female rival to the crimefighting prowess of Batman:

There's only one Batman! That's been said many times and has always been true, for no other man has ever rivaled Batman as a champion of the law, nor matched his superb acrobatic skill, his scientific keenness, his mastery of disguise and detective skill! But now, in one suspenseful surprise after another, Batman finds he has a great rival in the mysterious and glamorous girl...The Batwoman!

She was a costumed crime-fighter like Batman, yet in many ways not an exact counterpart. For example, the contents of her utility purse were actually weapons disguised as stereotypical feminine accoutrements such as lipstick, cosmetic compacts, charm bracelets, and hair nets. Batwoman appeared regularly in the pages of Batman and Detective Comics through the early 1960s. Although letters from fans indicated Batwoman had become popular with readers, editor Julius Schwartz considered the heroine, as well as other Batman-related characters, to be inappropriate for the new direction he planned to take the Batman universe. Following the revamp to Detective Comics in 1964, Batwoman was removed from the series. In 1967, a 'new' Batgirl, Barbara Gordon, was introduced, who not only replaced Batwoman as Batman's female counterpart, she surpassed the original heroine in popularity. Batgirl also proved to be more appropriate for her time period and the realistic approach DC Comics began taking with its characters. Unlike Batwoman, Gordon's Batgirl used a utility belt and various gadgets similar to Batman's, in addition to being a skilled martial artist and possessing a doctorate in her civilian identity. Despite requests from readers to revive Batwoman, DC's editorial staff initially declined to bring the character out of retirement, considering the fact that she was specifically created to be a love interest for Batman.

...Batwoman and Bat-Girl were there because romance seemed to be needed in Batman [and Robin]'s life. But thanks to the big change and a foresighted editor, these hapless females are gone for good. In their place stands a girl who is a capable crime-fighter, a far cry from Batwoman who constantly had to be rescued by [sic] Batman.

However, with the launch of the Batman Family comic book series in 1975, readers continued to request for Batwoman to appear in new stories. One reader states:

it is totally beyond me why you ignored Batwoman in your first two issues... I can understand your reluctance to go back to the days where everybody in Gotham had a Bat-identity, but you can't wipe out Batwoman that easily...I was counting on her making the scene in a new story, perhaps coming out of retirement to offer assistance to your Dynamite Duo [Batgirl and Robin].

Batwoman was brought back in Batman Family #10 (March–April 1977) as "Batgirl's guest heroine" when she comes out of retirement to capably assist Batgirl in defeating Killer Moth and the Cavalier; the two women even learn each other's secret identities during the story. Batwoman appeared two more times in the title, in issues #14 (1977) and #17 (1978). Batwoman then next appeared with Batgirl in two issues of Freedom Fighters #14 and #15 in 1978. However, in Detective Comics #485 (August–September 1979), Batwoman is killed by the League of Assassins (assisted by the Bronze Tiger). Editor Dennis O'Neil later stated in an interview, "we already had Batgirl, we didn't need Batwoman." The issue marked the final appearance of the Earth-1 Kathy Kane. An Earth-2 version appeared in The Brave and The Bold #182 (January 1982). This Kathy Kane retired from crime-fighting when that world's Batman married Catwoman; this world's Kathy was now married and with a family of her own. She comes out of retirement to help a grown-up Robin and the Earth-1 Batman battle the Earth-2 Hugo Strange.