The service to the mainly French-speaking city will operate from 11 May until 28 September, flying on Wednesdays from Quebec City and Thursdays from Gatwick.
Flights will be on a single-aisle Airbus A321neo LR.
Joseph Adamo, Air Transat’s chief sales and marketing officer, said: "We are proud to have been serving Quebec City since our very beginnings more than 30 years ago, and to be the leading international carrier departing from Jean Lesage Airport, with an array of exclusive routes that is constantly being enhanced."
Robert Mercure, general manager of Destination Quebec city tourism development organisation, added: