TMM may refer to:

• Transfer-matrix method, a statistical mechanics method
• Transfer-matrix method (optics), a method to describe wave propagation through stratified media
• Trimethylenemethane, a reactive organic compound and a ligand in organometallic chemistry

• Tell Me More (software), French language-learning software from Auralog
• Testing Maturity Model, a software process improvement model
• Too Much Media, an American software company based in New Jersey
• Traffic Management Microkernel, a product of F5 Networks
• Translation memory manager, a software program to aid human translators

• The Maybe Man, a 2023 studio album by American pop band AJR
• Tell Me More, an American radio show on National Public Radio hosted by Michel Martin
• Texas Memorial Museum, a museum at the University of Texas at Austin in the United States
• Textbook of Military Medicine, a U.S. Army publication
• Theresa May, a Prime Minister of the United Kingdom, from her full name Theresa Mary May
• TMM, the former ISO 4217 code of the Turkmenistani manat, the currency of Turkmenistan
• TMM-1 mine, an anti-tank landmine