OPP Const. Paul Nancekivell said police responded to the incident at about 3:30 p.m. in the Township of Amaranth in Dufferin County.
Nancekivell said the boy was found in the snow bank and was rushed to hospital where he succumbed to his injuries.
The boy's mother was on the scene and was taken to the hospital by police to be with her son.
Nancekivell said police are still investigating the incident and do not want to speculate about what the boy was doing in the snowbank.
"We're not sure whether it was a snow fort or not," said Nancekivell. "There was a hole dug into the bank."