Demetrios Christodoulou (Greek: Δημήτριος Χριστοδούλου; born 19 October 1951) is a Greek mathematician and physicist, who first became well known for his proof, together with Sergiu Klainerman, of the nonlinear stability of the Minkowski spacetime of special relativity in the framework of general relativity. Christodoulou is a 1993 MacArthur Fellow.