Jack the Ripper has never been definitively identified. And yet, the image constructed by Ripperologists and writers of Ripper fiction alike is strangely unequivocal in one aspect of identity, the masculinity of the serial sex murderer already encapsulated in his name Jack. “Jill the Ripper” by contrast, a theory attached to writer Arthur Conan Doyle, basically has no impact on the mythic image of the gentleman killer in popular fiction. But why is this? This chapter departs from the traditional gender politics of the Ripper and examines instances of Ripper fiction wherein Jack turns out to be Jill. Presumably no closer to historical truth than any of the theories, stories of female Rippers perform cultural work beyond speculative solutions in the sense that they question how we read and mentally construct the sex killer and his relationship to his victims. Feminist scholars criticise the one-dimensional portrayal of female characters in the Ripper story, stereotypically reduced to victims. Only occasionally, writers involve them in the narrative in a less passive manner, for instance focus on their experience or give them active roles, e.g. as (amateur) detectives. This sets up a binary opposition between them and the male killer, a conflict that almost amounts to ‘gender war’. But what if these expectations are subverted? From partnered killers to solo female Rippers, can such texts tell a new narrative, offer a different perspective? Or do they remain caught up in the existing myth and essentially become accomplices in the project of patriarchal terrorism?