Unifor represents about 4,800 workers at the railway including mechanics, clerical workers, excavator operators, locomotive engineers and truck drivers.
The ratification of a sixth tentative agreement covering workers who conduct safety inspections on rail cars and locomotives, as well as maintenance and repairs, is still underway, the union said Monday.
The new agreements include wage increases in each of the four years, improvements to benefits, stronger job security and other changes.
The union and the railway will also partner to create a fund which will focus on issues related to women's equality and aboriginal issues.
CN and Unifor reached the tentative agreement late last month, narrowly avoiding a lockout threatened by the company.