The Grey Bruce Health Unit say five cases were confirmed at St. Mary’s High School on Friday.
Officials have identified eleven cohorts and one bus connected to this outbreak.
They say the school will remain closed out of an abundance of caution and all in-school learning with be shifted to a virtual setting.
In the meantime, the health unit ask that all students and staff get tested for COVID-19 at the nearest assessment centre.
A drive-thru assessment centre is being planned in the parking lot of the health unit in Owen Sound that will operate Monday, Tuesday, and Wednesday from 11 AM until 3 PM.