Maddy is a surname. Notable people with the surname include:
Darren Maddy (born 1974), English cricketer
Joseph E. Maddy (1891–1966), American music educator
Kenneth L. Maddy (1934–2000), American politician
Paul Maddy (born 1962), Welsh former footballer
Penelope Maddy, Professor of Logic and Philosophy of Science and of Mathematics at the University of California, Irvine
Yulisa Pat Amadu Maddy (born 1936), Sierra Leonean actor, dancer, director and playwright
