Students at Martensville High School are immediately moving to remote learning under level 4 of the Safe Saskatchewan Schools Plan.
PSSD has not said if the cases are in students or staff.
The school division said it consulted with the Saskatchewan Health Authority and the Ministry of Health in making the decision.
Under level 4, in-class learning is suspended, moving to online learning with attendance mandatory.
PSSD said the high school will move to level 3 on Nov. 23, which will continue until at least the Christmas break.
In level 3, classroom capacity is reduced and cohorts and hybrid learning could be established, according to the safe school plan.
The school division said its plans depend on further direction from the health authority.