Pope Leo XII (; born Annibale Francesco Clemente Melchiorre Girolamo Nicola della Genga; 2 August 1760 - 10 February 1829) was head of the Catholic Church and ruler of the Papal States from 28 September 1823 to his death in February 1829.'

Leo XII was in ill health from the time of his election to the papacy to his death less than six years later, though