Michael Anthony Viscardi (born February 22, 1989 in Plano, Texas) of San Diego, California is a young American mathematician who won the 2005 Siemens Competition and Davidson Fellowship with a mathematical project on the Dirichlet problem, whose applications include describing the flow of heat across a metal surface, winning $100,000 and $50,000 in scholarships, respectively. Viscardi's theorem is an expansion of the 19th-century work of Peter Gustav Lejeune Dirichlet.