PLT may stand for:
- Patent Law Treaty
- Plantronics, stock symbol
- Platelet count, in blood test reports
- Power line communication or power line telecommunications
- Princeton Large Torus, a nuclear fusion reactor
- Programming language theory, in computer science
- PLT Scheme, a programming language
- PrettyLittleThing, fashion brand
- Procedure Linkage Table, a programming concept related to GOT.