| District Name | District Number | Total Enrollment |
|---|---|---|
| O'DONNELL | 153903 | 432 |
| OAKWOOD | 145907 | 277 |
| ODEM-EDROY | 205905 | 1238 |
| OGLESBY | 050904 | 143 |
| OLFEN | 200906 | 90 |
| OLNEY | 252903 | 864 |
| OLTON | 140905 | 835 |
| ONALASKA | 187910 | 491 |
| ORANGE GROVE | 125903 | 1336 |
| ORANGEFIELD | 181905 | 1521 |
| ORE CITY | 230903 | 844 |
| OVERTON | 201908 | 464 |