Celestina Sommer (née Christmas; 1 July 1827 – 11 April 1859) was a Victorian murderer, notorious as much for her escape from the death penalty as for the murder of her only daughter. Known as the Islington Murderess, she became an international cause célèbre, examined in the world's press, both houses of the British Parliament, and even Queen Victoria's inner circle. Her case, recently rediscovered, reignited the fierce debates on crime and insanity, capital punishment and crime and gender.