The 16-year-old is already incarcerated for another related crime and will serve the sentence consecutively, the Public Prosecution Service of Canada said.
He had become radicalized and stole Can$2,200 (US$1,680) at knife-point from a Quebec store in order to pay for travel to Syria where he hoped to join the Islamic State group and take part in the conflict there.
His father alerted police and the boy, who was 15 years old at the time, was arrested before he could leave the country.
Under Canadian law, youths convicted of crimes cannot be publicly identified.
Local media citing expert court testimony said he has started to renounce radicalism.
