John Mack can refer to:

• John Mack (1927- ), the American oboist.
• John Mack, the English missionary preacher who worked with Marshman and Carey the 18th century Serampore missionaries in India.
• John Edward Mack (1929-2004), the American psychiatrist known for his interest in alien abduction.
• John J. Mack (1945?- ), CEO and Chairman of the Board of Morgan Stanley.