Terahertz or THz may refer to:
- Terahertz (unit), a unit of frequency, defined as one trillion (10<sup>12</sup>) cycles per second or 10<sup>12</sup> hertz
- Terahertz radiation, electromagnetic waves within the ITU-designated band of frequencies from 0.3 to 3 terahertz
- Terahertz spectroscopy and technology
- Intel TeraHertz, a transistor design
See also
- Terahertz gap, a band of frequencies in the terahertz region of the electromagnetic spectrum