| Abbreviation | Definition |
|---|---|
| IBL | Independent Baseball League |
| IBL | Intercounty Baseball League |
| IBL | Internet Baseball League |
| IBL | Iowa Baseball League |
| IBL | Italian Baseball League |
| IBLA | International Baseball League of Australia |
| IBLJ | Intercounty Baseball League of Japan |
| ICBA | Inter County Baseball Association |
| ICBB | Iowa City Boys Baseball |
| ICYB | Inner City Youth Baseball |
| IL | Injured List |
| ILB | Independence League Baseball |
| INN | INNings pitched |
| INN | INNings played |
| IPS | Innings Per Start |
| ISBL | International Simulated Baseball League |
| ISLB | Independent School League Baseball |
| ITBL | Inter Town Baseball League |
| IW | Intentional Walk |
| IYB | Ixonia Youth Baseball |