[1] In 2006, Larsonneur graduated in European Affairs at Sciences Po Lille and in Philosophy, Politics and Economics (PPE) at the University of Kent in Canterbury.
From 2008 to 2009, Larsonneur taught European History and Political Philosophy at the University of Greenland in Nuuk, as part of the International Volunteer in Administration (VIA) program at the French Embassy in Denmark.
He served as a political adviser in charge of commercial diplomacy in the Directorate on European Affairs, relations with Brazil and South America, and NATO partnerships from 2011 to 2013.
In addition to his work as a diplomat, Larsonneur taught European affairs at the ÉNA preparatory classes at École normale supérieure (ENS).
[6] In July 2019, Larsonneur voted in favour of the French ratification of the European Union’s Comprehensive Economic and Trade Agreement (CETA) with Canada.