Vat or VAT may refer to:
- A type of container such as a barrel, storage tank, or tub, often constructed of welded sheet stainless (corrosion resistant) steel, and used for holding, storing, and processing liquids such as milk, wine, and beer
- Value added tax, a consumption tax levied on value added
- Vanajan Autotehdas, a defunct heavy vehicle producer
- Vát, a village in Hungary
- Vatican Library, the library of the Vatican
- Vat dyes, a type of water-insoluble dyes
- VAT identification number
- Vodka tonic, a mixed drink
- Virtual Allocation Table, a component of the Universal Disk Format
- A form of Việt-Võ-Đạo, the philosophy behind many Vietnamese martial arts