Michael Piazza may refer to:

• Mike Piazza, former Major League Baseball catcher
• Michael S. Piazza, author and social justice advocate

• Polish Socialist Party – Freedom, Equality, Independence
• Polish Socialist Workers Party
• Polish society
• Polish Society of Allergology
• Polish Society of War Veterans
• Polish Society of War Veterans and Former Political Prisoners
• Polish Sociological Society
• Polish sociology
• Polish Song Festival in Opole
• Polish songs (Chopin)
• Polish-South Korean relations
• Polish-Soviet border agreement
• Polish-Soviet border treaty (disambiguation)
• Polish-Soviet Friendship Society
• Polish-Soviet relations
• Polish-Soviet War
• Polish-Soviet War in 1919
• Polish-Soviet War in 1920
• Polish-Soviet war of 1920
• Polish Speaker of the Senate
• Polish Special Forces
• Polish Sportspersonality of the year
• Polish stage of the UEFA Regions' Cup
• Polish State Railroads Summer 1939
• Polish Stock Exchange