UST or Ust may refer to:
Organizations
- UST (company), American digital technology company
- Equatorial Guinea Workers' Union
- Union of Trade Unions of Chad (Union des Syndicats du Tchad)
- United States Television Manufacturing Corp.
- UST Growling Tigers, men's varsity team
- UST Inc., tobacco company
Universities
- University of Science and Technology (disambiguation)
- Hong Kong University of Science and Technology (HKUST)
- Korea University of Science and Technology in South Korea
- University of Santo Tomas in Manila, Philippines
- University of St. Thomas (Minnesota)
- University of St. Thomas (Texas) in Houston, US
Places
- Northeast Florida Regional Airport, St. Augustine, US, IATA Code
- Oskemen, Kazakhstan: Ust-Kamenogorsk in Russian
- Qala Wust or Ūst, Badakhshan Province, Afghanistan
- Ust-Luga, near Luga Bay of the Gulf of Finland
Other uses
- Universal System Tubeless, a tubeless tire rim patented by Mavic
- Underground storage tank
- United States Treasury security, a bond issued by the federal government
- Unsepttrium, an unsynthesized chemical element
- .ust, file extension for Utau project files
- Ultimate Success Today, 2020 Protomartyr album
- TerraUSD (by ticker symbol), a stablecoin cryptocurrency developed by Do Kwon