PTT is an acronym that may stand for:
- Postal Telegraph and Telephone (several);
- Postal Telephone and Telegraph (several);
- Public Telegraph and Telephone (several);
- Public Telephone and Telegraph (several);
- Post Telefon Telegraph (Germany);
- Poste, Téléphone et Télécommunications (France);
- Ministry of Post, Telegraph and Telephone (Iran);
- Part task trainer (military);
- Partial thromboplastin time;
- Partido Trabalhista Timorense ;
- Polytrimethylene terephtalate ;
- Protein truncation test ;
- Push to talk.
