Michael O'Donnell

• Michael O'Donnell (physician), British doctor, journalist, author, and broadcaster
• Michael O'Donnell (Kansas politician), American researcher, and lecturer
• Michael E. O'Donnell, American biochemist
• Michael O'Donnell (rugby league), New Zealand former professional rugby league footballer
• Michael A. O'Donnell, American writer and researcher
• Michael O'Donnell (Missouri politician), politician in Missouri