No details were released, but Unifor says the agreement includes a significant hourly wage increase for those at the lower end of the salary grid.
Air Canada says its board of directors has also approved the new agreement, which was reached on June 14.
Airline president and CEO Calin Rovinescu said in a statement that the agreement is a "win-win" and noted this is the fourth labour contract Air Canada has concluded over the past eight months.
Voting on the agreement, which is effective from March 1 this year to Feb. 28, 2020, took place over the past eight days.
The customer service agents and sales agents had walked off the job for three days in June 2011.
During roughly the same period, the airline faced protracted negotiations with both flight attendants and pilots. In 2012 baggage handlers staged an illegal walkout before being forced back to work by a court order.
"This agreement secures good jobs for customer sales and service agents now and into the future," Unifor president Jerry Dias said in a statement late Thursday.