ZTO
| Acronym | Definition |
|---|---|
| ZTO | Zeta Tau Omega (sorority; est. 1999) |
| ZTO | Zinc Tin Oxide |
| ZTO | Zentrum fur Technische Orthopadie (German: Center for Technical Orthopedics) |
| ZTO | Zaklad Techniki Odpylania (Polish: Department of Dust Removal Technology) |
| ZTO | Zero Time Outage |
| ZTO | Zambezi Times Online (news website; Zambia) |
| ZTO | Zone Transportation Office |
| ZTO | Zoom Theory Optimal (poker) |
| ZTO | Zone Transportation Officer |