The Edmonton Police Service said the boy's father gave him bus fare for his return home from Edmonton's City Centre mall.
His father said he last saw the boy at 1:30 p.m.
Tarrin is described as 4 feet 10 inches tall with a stocky build and long, dark hair. He was last seen wearing a light-blue hooded jacket with the letters "STC" on the back, red shorts and green Nike shoes, Global News reported.
Those with information about the boy's whereabouts are encouraged to call police at 780-423-4567.