Ontario will be restricting the use of cellphones in classrooms starting in November.
The government had originally announced the ban earlier in the year, saying it would be in effect for the start of the school year.
A spokeswoman for Education Minister Stephen Lecce says the delay is to give school boards time to implement the restriction.
The directive says students can only use personal mobile devices during instructional time if it is for educational purposes, for health or medical purposes, or for special needs.
Some schools already have similar policies, but the directive sets a provincial standard.
The Progressive Conservatives had proposed such a ban in their platform during last year's election campaign.