**Camillo De Lellis** (born June 11, 1976) is an Italian mathematician who is active in the fields of calculus of variations, hyperbolic systems of conservation laws, geometric measure theory and fluid dynamics.

De Lellis received his Ph.D. in mathematics from the Scuola Normale Superiore at Pisa, under the guidance of Luigi Ambrosio in 2002. He is currently professor of mathematics at the University of Zurich. De Lellis has given a number of remarkable contributions in different fields related to partial differential equations. In geometric measure theory he has been interested in the study of regularity and singularities of minimising hypersufaces, pursuing a program aimed at disclosing new aspects of the theory started by Almgren in his "Big regularity paper". There Almgren proved his famous regularity theorem asserting that the singular set of an *m*-dimensional mass-minimizing surface has dimension at most *m* − 2. De Lellis has also worked on various aspects of the theory of hyperbolic systems of conservation laws and of incompressible fluid dynamics. In particular, together with László Székelyhidi Jr., he has introduced the use of convex integration methods and differential inclusions to analyse non-uniqueness issues for weak solutions to the Euler equation.

De Lellis has been awarded the Stampacchia medal in 2009, the Fermat Prize in 2013 and the Caccioppoli Prize in 2014. He has been invited speaker at the International Congress of Mathematicians in 2010 and plenary speaker at the European Congress of Mathematics in 2012. In 2012 he has also been awarded an ERC grant.