| Westside Secondary School | |
| Address: | 300 Alder Street |
| Country: | Canada |
| Coordinates: | 43.9058°N -80.1238°W |
| Founded: | 1999 |
| Principal: | April King |
| Grades: | 9-12 |
| Enrollment: | 800[1] |
| Enrollment As Of: | 2019/2020 |
| Language: | English |
| Colours: | Red and Black |
| Team Name: | Westside Thunder |
Westside Secondary School is a public high school located in Orangeville, Ontario, Canada that opened on November 25, 1999. The current population is 800 students.