Hippolyte-Prosper-Olivier "Lissa" Lissagaray (November 24, 1838 in Toulouse – January 25, 1901 in Paris) was a literary animator and speaker, a Republican journalist and a French revolutionary socialist.[1]

Lissagaray was born at Toulouse to pharmacist Laurent Prosper Lissagaray and Marie-Louise Olympe Boussès de Foucaud.[2][3] On his father's side, his great-grandfather was a landowner and farmer of 200 hectares, and his grandfather a doctor.[4] The journalist Paul de Cassagnac was a cousin of Lissagaray, with whom he had a fractious relationship; his father's mother, Ursule (1775-1850), was the sister of Laurent Prosper Lissagaray. Disagreement over financial matters related to Ursule's dowry led to the poor relationship between the Lissagarays and Cassagnacs after Laurent Prosper Lissagaray's death.[5][6]