JTAC may refer to:
- JTAC Hill
- Joint Terrorism Analysis Centre
- Joint terminal attack controller
- Total Access Communication System (TACS), an analogue mobile-phone standard also known as Japanese Total Access Communication (or JTAC)
- Juniper Networks Technical Assistance Center.
- Journal of Thermal Analysis and Calorimetry is a peer-reviewed scientific journal that publishes papers covering all aspects of thermal analysis, calorimetry, and experimental thermodynamics.