| Abbreviation | Definition |
|---|---|
| NSHA | National Spanish Horse Association |
| NSHA | North Shore Horsemens Association |
| NSL | National Shopping League |
| NSS | National Speleological Society |
| NSSC | Newhaven and Seaford Sailing Club |
| NSSC | North Star Sail Club |
| NSTRA | National Shoot To Retrieve Association |
| NTAG | North Texas Audi Group |
| NTSF | North Texas Samoyed Fanciers |
| NUC | National Unicycle Convention |
| NWBC | NorthWest Buckskin Club |
| NWC | Nissan Wheelers of Colorado |
| NWMG | North West Meccano Guild |
| NWQ | North Wind Quilters |
| NWS | National Watercolor Society |
| NXN | Nike Cross Nationals |
| NYQ | New York Quilts |
| O | Original |
| OAF | Ontario Attack Force |
| OALN | On A Lighter Note |