MTL

Possible meanings:

* An abbreviation of Montreal, Canada
* An abbreviation of Mount Laurel, New Jersey
* The official abbreviation for the Muldentalkreis district in the Free State of Saxony, Germany
* The ISO 4217 code for the Maltese lira, the former currency of Malta
* Modern Taiwanese Language, an ortography in the Latin alphabet for the Taiwanese language
* Mother tongue language, or first language

Science and technology

* Material Template Library, a file format that describes the material for an accompanying obj file
* Matrix Template Library, a linear algebra library for C++ programs
* Microsystems Technology Laboratories [http://www-mtl.mit.edu/] at the Massachusetts Institute of Technology
* Minimum Threshold Level, representing the minimum usable signal level in operation of a receiver
* Model Transformation Language, a generic term for various languages to perform transformations on mathematical models
* Monoidal t-norm logic, the logic of left-continuous t-norms

Products and companies

* Modern Terminals Limited, a container terminal operator in Hong Kong
* MTL (transport company), a defunct bus, coach and train operator in the United Kingdom
* MTL Instruments Group
* The first Nordic mobile telecomsystem named after Sture Lauhrén