Dennis McCarthy may refer to: Dennis McCarthy (scientist), American scientist Dennis McCarthy (composer) (born 1945), American composer Dennis McCarthy (congressman) (1814–1886), Lieutenant Governor of New York, 1885 Dennis McCarthy (radio presenter) (1933–1996), British radio presenter Denis Florence MacCarthy (1817–1882), Irish poet Dennis M. McCarthy (born 1945), U.S. Marine Corps general Dennis McCarthy, shooting victim of Colin Ferguson