Dennis McCarthy may refer to: Dennis McCarthy (scientist), American scientist Dennis McCarthy (composer) (born 1945), American composer Dennis McCarthy (New York politician) (1814–1886), United States congressman and acting lieutenant governor of New York Dennis McCarthy (radio presenter) (1933–1996), British radio presenter Denis Florence MacCarthy (1817–1882), Irish poet Dennis M. McCarthy (1945–2023), U.S. Marine Corps general Dennis McCarthy, shooting victim of Colin Ferguson