François Loeser (born August 25, 1958) is a French mathematician. He is Professor of Mathematics at the Pierre-and-Marie-Curie University in Paris. From 2000 to 2010 he was Professor at École Normale Supérieure. Since 2015, he is a senior member of the Institut Universitaire de France.
He was awarded the CNRS Silver Medal in 2011 and the Charles-Louis de Saulces de Freycinet Prize of the French Academy of Sciences in 2007. He was awarded an ERC Advanced Investigator Grant in 2010 and has been a Plenary Speaker at the European Congress of Mathematics in Amsterdam in 2008. In 2015 he was elected as a fellow of the American Mathematical Society "for contributions to algebraic and arithmetic geometry and to model theory".
He is a specialist of algebraic geometry and is best known for his work on motivic integration, part of it in collaboration with Jan Denef.