PTH may refer to:
Biology and Medicine
- Parathyroid hormone
- phenylthiohydantoin, an amino acid derivative formed by the Edman degradation
Computing
- GNU Portable Threads in computing
- Pass the hash attack in computing
Languages
- Pataxó language, by ISO 639 code
- Standard Chinese, also known as putonghua and abbreviated PTH
Places
- Port Huron (Amtrak station), Michigan, US, station code
- Perth railway station, Scotland, station code
- Provincial Trunk Highway in list of Manitoba provincial highways
- Port Heiden Airport, by IATA code
Other
- Plated through-hole in PCB through-hole technology
- Polskie Towarzystwo Historyczne, the Polish Historical Society