may be an abbreviation for:
- Tabb Middle School, a middle school in Yorktown, Virginia
- Tamanend Middle School, a middle school in Pennsylvania
- Temasek Secondary School, a secondary school in Bedok, Singapore
- The Machine Stops, a Pennsylvania rock band
- The Minerals, Metals & Materials Society, a professional organization for materials scientists and engineers
- Tokyo Movie Shinsha, a major Japanese animation studio now known as TMS Entertainment
- Toyota Motor Sales, U.S.A., Inc., an American subsidiary of Toyota Motor Corporation which handles sales and distribution of Toyota and Scion automobiles in the United States
- Triadelphia Middle School, a school located near Wheeling, West Virginia
- Tribune Media Services, a syndication company owned by the Tribune Company
- Toronto Montessori Schools, a Montessori school in Richmond Hill, Ontario
- Tyrrell Middle School, a middle school in Wolcott, Connecticut
- Tactical Mercinary Squad, a steam group
Medicine & psychology
- Tape Management System, computer software used for the management of computer backup tapes.
- Thai MapleStory, a 2D side-scrolling Massively Multiplayer Online Role Playing Game
- Tile Map Service, A GIS specification for providing rendered map tiles at fixed scales, similar to Google maps.
- TrackMania Sunrise, a computer racing game
- Advanced traffic management system, a subsystem of an Intelligent Transportation System
- Transportation management system, a category of logistics software products
- Transport management system, an SAP process for managing transports
- Truth maintenance system, a knowledge representation method
- Too Much Security, an increasingly common situation caused by security mania in corporate IT and in general, often resulting in negative consequences.