The 14-year-old boy faces a charge of possession of a weapon or an imitation thereof as a result of the Sept. 24 incident.
RCMP Sgt. Craig Seafoot says the toy was an imitation of an old flintlock handgun.
"You don't bring firearms, whether they're toys or not, to school," Seafoot said, pointing to school shootings in the United States.
"It's a potentially dangerous situation and that's the way we treat it."
Principal Al Karasiuk, who was away from the school for meetings at the time, says the incident was dealt with by vice-principal Jeff O'Keefe.
"There was a report of a student having a gun in his locker," Karasiuk says, describing it as a non-functional replica.
The Grade 9 student was immediately brought to the school's office. He had the replica in his possession at the time. O'Keefe took the replica and called police. The principal says the incident did not create any commotion at the school, noting not many people knew it had even taken place.
"I don't think people were disconcerted at the time," he said.
There was no evacuation, Karasiuk added.
"The individual was not threatening anyone. There was no apparent threat at the time."
Following the incident, the school has reviewed its emergency response procedures. The student is currently suspended from the school as a result of the incident, which is believed to be the first of its kind at PWK. The boy will appear in Youth Court on Nov. 25.