| Abbreviation | Definition |
|---|---|
| NCBA | Northern California Baseball Association |
| NCBL | National Capital Baseball League |
| NCBWA | National College Baseball Writers of America |
| NCBWA | National Collegiate Baseball Writers of America |
| NDBA | Niagara District Baseball Association |
| NDBA | North Delta Baseball Association |
| NEBC | New England Baseball Complex |
| NEBS | North Edison Baseball and Softball |
| NFBC | National Fantasy Baseball Championship |
| NFBC | National Fantasy Baseball Championships |
| NGBL | National Girls Baseball League |
| NKA | Northbrook Kids Baseball |
| NKB | Northbrook Kids Baseball |
| NKB | Northern Kentucky Baseball |
| NL | National League |
| NLB | National League Baseball |
| NLB | Negro Leagues Baseball |
| NLB | Nevers Larkin Baseball |
| NLBA | New Lenox Baseball Association |
| NLBPA | Negro League Baseball Players Association |