O Fallon High School
| Name | O Fallon High School |
| Grades | Class 09 to Class 12 |
| Address | 600 S Smiley St |
| City | O Fallon |
| School District | O Fallon Twp HSD 203 |
| County | St. Clair County |
| Zipcode | 62269-2316 |
| Phone No. | (618)632-3507 |
| State | Illinois |
| Suburb | Large |
| Students | 2511 |
| Teachers | 0 |
| Student Teacher Ratio | 0 students per teacher |
| Charter School | No |
| Magnet School | N/A |
O Fallon High School is located at 600 S Smiley St in O Fallon city of St. Clair County county in Illinois. This school comes under O Fallon Twp HSD 203. You can call them at (618)632-3507 for more details. This is not a magnet school. Total two thousand five hundred eleven students from class 09 to class 12 study in this school who are taught by teachers. This is not a charter school. The student teacher ratio of this school is 0.