The following Extra-Curricular events take place in St. Sebastian C.E.S.:
| Junior Chorus | Diversity Club | Virtues Club |
| Youth Faith Ambassadors | Heads Up Academic Team | Junior Volleyball |
| Intermediate Volleyball | Chess Club | Eco School Team |
| Intermediate Basketball | Junior Basketball |
Cross Country Team |
| Art Club | Co-Ed Softball Team | PALS -Playground Activity Leaders |
| Hockey Team | Soccer Teams | Flag Football Team |
| Track & Field | Terry Fox | Card Club |
| Autism Awareness | Jump Rope for Heart | Shining Stars |
| School Musical | Primary Play Day | FDK Play Day |