Michael or Mike Cassidy may refer to:Michael Cassidy (1937–2025) Michael E. Cassidy, American politician Michael Cassidy (actor), American film and television actor Michael Cassidy (sailor) (1837–1908), American Civil War sailor and Medal of Honor recipient Mike Cassidy (entrepreneur), American entrepreneur; CEO and co-founder of Internet start-ups Mike Cassidy (1926–2011), American and Canadian football player Mike Cassidy (spearfisher), Guamanian spearfisher Mick Cassidy, English rugby league player Michael Cassidy (evangelist), South African Christian evangelist