STM
STM may refer to:

Technology
Scanning tunneling microscope, a non-optical microscope
Signature-tagged mutagenesis, a genetic technique to create random mutants
STMicroelectronics, a Dutch manufacturer of electronics and semiconductors
STM (Turkish company) (Savunma Teknolojileri Mühendislik ve Ticaret A.Ş.), a military technology company in Turkey
STM-1, Synchronous Transport Module, the basic rate of transmission of the SDH ITU-T fiber optic network
STM32, a family of 32-bit microcontroller integrated circuits by STMicroelectronics
Software transactional memory, a method of handling concurrency in multithreaded systems
Stepper motor, a type of electric motor
Canon autofocus lenses that use stepper motor technology which makes them especially quiet
.stm, a filename extension used by:
Web administration panel, of Belkin routers
Streaming Media File, in Microsoft Exchange Server
Scream Tracker, music tracker software

Transportation
Société de transport de Montréal, the public transport provider in Montreal, Quebec, Canada
Amtrak ticketing code for Stamford Transportation Center, a railway station in Stamford, Connecticut, US
National Rail for St Michaels railway station in Liverpool, England, UK
Sea traffic management, a set of systems and procedures to guide and monitor sea traffic in a manner similar to air traffic management
Space traffic management
Strategic Traffic Manager, a Bus Priority application designed to work as part of an intelligent transportation system
Santarém-Maestro Wilson Fonseca Airport, Santarém, Pará|Santarém, Brazil, by IATA airport code
St. Thomas Mount railway station, Chennai, Tamil Nadu, India, by station code
Sydney Tramway Museum, New South Wales, Australia

Publishing
International Association of Scientific, Technical, and Medical Publishers, an association of publishers
Science, technology, and medical publishing, a market segment of academic publishing
Science Translational Medicine, an American medical journal

Other uses
Sacrae Theologiae Magister, or Master of Sacred Theology, an academic degree
St Thomas College of Engineering and Technology, Kannur , Kerala , India
St. Thomas More College, a Catholic, undergraduate, liberal arts college located in Saskatoon, Saskatchewan, Canada
St. Thomas More Collegiate, a Catholic secondary school in Burnaby, British Columbia, Canada
Short-term memory, the capacity for holding a small amount of information for a short period of time
Small Tactical Munition, a weapon developed by Raytheon
Stabilisation Tracking Mechanism, the mirror instrument of the Stabilisation and Association Process (SAP) for Kosovo
ST"M, a Hebrew acronym meaning a scribe

See also
STM200, a pseudonym for Takeshi Matsumoto, musician featured in the music video game Dance Dance Revolution 5thMix
STEM fields, an education and publishing classification
ST1M a.k.a. Billy Milligan, real name Nikita Legostev, a Russian rapper