| Abbreviation | Definition |
|---|---|
| NOMA | New Orleans Museum of Art |
| NOMM | National Ornamental Metal Museum |
| NORM | Northern Ohio Railway Museum |
| NPG | National Portrait Gallery |
| NPM | National Palace Museum |
| NRCMA | National Roller Coaster Museum and Archives |
| NRCMA | National Roller Coaster Museum Archives |
| NRM | National Railway Museum |
| NRM | Norman Rockwell Museum |
| NSHS | Nebraska State Historical Society |
| NSMK | National Science Museum of Korea |
| NSMM | National Science and Media Museum |
| NSMO | National Science Museum Organization |
| NSTM | National Science and Technology Museum |
| NT | No Tour |
| NTMOFA | National Taiwan Museum of Fine Arts |
| NTTM | National Toy Train Museum |
| NUMF | Naval Undersea Museum Foundation |
| NVM | Napa Valley Museum |
| NVM | National Videogame Museum |