ZSO
| Acronym | Definition |
|---|---|
| ZSO | Zoroastrian Society of Ontario (est. 1971; Ontario, Canada) |
| ZSO | Zveza Slovenskih Organizacij (Slovenian: Association of Slovenian Organizations) |
| ZSO | Zelda's Secret Ocarina (website) |
| ZSO | Open Limit Switch (control systems) |
| ZSO | Zwols Symfonie Orkest (Dutch: Zwols Symphony Orchestra; Olst-Wijhe, Netherlands) |
| ZSO | Zemaitijos Skautu Organizacija (Lithuanian: Samogitia Scouts Organization) |