There was no income tax in Canada till World War I.
1917 - during WW I, the Income War Tax Act imposed a 4% tax on income over $2,000 yearly for all single men; and for others on income over $3,000 but under $6,000. There was a graduated tax rate for those with incomes over $6,000.
See WarTime Canada for more about taxation in Canada during this period and World War II. Includes sample historical tax forms.