Michael Costello may refer to:

• Michael Costello (actor), American actor
• Michael Costello (public servant), ex-chief of staff to Australian politician Kim Beazley
• Michael A. Costello (born 1965), State Representative for the Massachusetts House of Representatives
• Michael Costello (fashion designer) (born 1983), American fashion designer and contestant on Project Runway
• Michael Copps Costello (1875–1936), Canadian politician
• Mike Costello, British sports broadcaster
• Michael Joe Costello (1904–1986), Irish Army general
• Mick Costello (born 1936), British communist activist

• Prophets in Islam
• Prophet's Mosque
• Prophets of Da Cape
• Prophets of da Cape
• Prophets of Da City
• Prophets (Star Trek)
• Prophet (Star Trek)
• Prophetstown, IL
• Prophetstown, Illinois
• Prophetstown State Park
• ProPhoto RGB color space
• Prophylactic
• Prophylaxis
• Prophylaxis (chess)
• Propidium iodide
• Propietary
• Propinquity
• Propinquity effect
• Propionate
• Propionibacterium
• Propionic acid
• Propionic acidemia
• Propiska in the Soviet Union
• Propithecus
• Propithecus verreauxi