Michael Hennessy (disambiguation)

Michael or Mike Hennessy or Hennessy may refer to:


 * Michael Hennessey (born c. 1948), American attorney and former Sheriff of San Francisco
 * Mike Hennessey (1928–2017), English music journalist and jazz pianist
 * Michael Hennessy (fl. 1920s–1930s), Irish politician and businessman
 * Mike Hennessy (fl. 1990s–2000s), British rower,
 * Michael "Mickey" Hennessy (1915—1991), Canadian boxer and politician