Andrew John Sommese is an American mathematician, specializing in algebraic geometry.
Sommese received in 1969 from Fordham University a bachelor's degree and in 1973 from Princeton University a PhD under Phillip Griffiths with thesis Algebraic properties of the period-mapping. As a postdoc Sommese was from 1973 to 1975 a Gibbs Instructor at Yale University and was for the academic year 1975–1976 at the Institute for Advanced Study. He became at Cornell University in 1975 an assistant professor and at the University of Notre Dame in 1979 an associate professor and in 1983 a full professor. At the University of Notre Dame he was from 1988 to 1992 the chair of the mathematics department and from 1987 to 1992 the co-director of the Center for Applied Mathematics. Since 1994 he is there Duncan Professor for mathematics.
Sommese deals with numerical algebraic geometry with applications, e.g. in robotics. For such applications he, with colleagues, developed software and cluster-software. He also deals with the numerical analysis of systems of nonlinear differential equations.