At Night All Blood Is Black is a novel by French author David Diop. First published in French on August 16, 2018, by Éditions du Seuil, it won the Prix Goncourt des Lycéens that same year.  The English translation by Anna Moschovakis won the 2021 International Booker Prize. It was published in the UK by Pushkin Press and in the US by Farrar, Straus and Giroux.