TSD may refer to:
Businesses and organizations TSD Desalination, an Israeli start-up Telluride School District R-1 Texas School for the Deaf, U.S. Transylvanian Society of Dracula Turin School of Development, Italy University of Wales Trinity Saint David, a university in the U.K.
Government Technical Services Division, another term for the U.S. CIA's Office of Technical Service Treatment, Storage, and Disposal Facility; see HAZWOPER Treasury Solicitor's Department, U.K. Trilateral Security Dialogue, part of the Quadrilateral Security Dialogue Technical Support Division ad hoc Indian Army Intelligence Unit.
Science and medicine Target-to-skin distance, a measurement in external beam radiotherapy Tay–Sachs disease, a genetic disorder, fatal in its most common variant Temperature-dependent sex determination Thermionic specific detector, another term for nitrogen–phosphorus detector Total sleep deprivation, a parameter in sleep and memory studies
Other uses TSD (band), a 1990s girl band TSD rally (time-speed-distance), a type of motorsport rally ISO 639:tsd or Tsakonian, a modern Hellenic language which is highly divergent from other spoken varieties of Modern Greek Tang Soo Do, a Korean martial art Text, Speech and Dialogue, an international conference held in the Czech Republic Toshiba Telecommunication Systems Division, Irvine, California Turtle saving device, another term for turtle excluder device