JMM can refer to:
People John Michael Montgomery, American country music singer Juan Manuel Márquez, Mexican boxer John Mark McMillan, American songwriter and musician
Science and technology Java Memory Model, the model which defines execution-time constraints on the relationship between threads and data in order to achieve consistent and reliable Java applications.
Organizations and business Jacques Marie Mage, luxury sunglasses brand Jharkhand Mukti Morcha, a political party in India Jabheh-yi Mubarizin-i Mardumi (Balochi for People's Fighters Front), a Baloch nationalist militant organization in Iran
Others Jamiatu Muslim Mindanao, one of the oldest and biggest Madaris in the Philippines
Jesuit Music Ministry, a record label in the Philippines. Jewish Military Museum, London, England
James Morgan McGill (aka Saul Goodman) a character in AMC's Breaking Bad and the main character of its spin-off Better Call Saul. "JMM" (Better Call Saul), an episode of Better Call Saul
Joint Mathematics Meetings, an annual mathematics conference hosted by the MAA and AMS Journal of Medical Microbiology, a scientific journal