| Abbreviation | Definition |
|---|---|
| OWHS | Old Woodbury Historical Society |
| OWHS | Old World Hereditary Societies |
| OWLS | Otsego Wildlife Legacy Society |
| OWS | Old Wrights Society |
| OWSS | Old West Shooting Society |
| OYS | Omnipotent Youth Society |
| OZS | Oklahoma Zoological Society |
| PA | Palaeontological Association |
| PAAA | Pan American Aerobiology Association |
| PABS | Pan Africa Burn Society |
| PABS | Pan African Building Society |
| PACES | Pediatric and Congenital Electrophysiology Society |
| PACS | Poorest Areas Civil Society |
| PACS | Primary Agricultural Credit Society |
| PADFAS | Painswick Area Decorative And Fine Arts Society |
| PALS | Pet Adoption and Lifecare Society |
| PAM | Malaysian Institute of Architects |
| PAM | Pertubuhan Akitek Malaysia |
| PAMS | Pan American Montessori Society |
| PAMS | Peruvian American Medical Society |