MTT
- MTT assay
- Maria Theresa thaler
- Maritime Telephone and Telegraph Company
- Meaning–text theory
- Metropolitan Transport Trust
- Mettaton
- Michael Tilson Thomas
- Minatitlán/Coatzacoalcos National Airport
- Modus tollens
- Multi-table tournament
- Multi-transaction translator
- Multi-troop transport
- Municipal Tramways Trust
- Pashtun Tahafuz Movement
- Undertale