The outbound service from the London airport will operate on Wednesdays, Fridays and Sundays and the return service on Tuesdays, Thursdays and Saturdays.
Flights are operated with Boeing 787-9 Dreamliner aircraft, featuring 30 Air Canada signature class, 21 premium economy and 247 economy seats.
Air Canada now has a monopoly on Heathrow-Calgary services after British Airways axed the destination in March.
Air Canada currently offers daily nonstop services from Heathrow to Toronto and Vancouver, as well as a four-times weekly nonstop service between Heathrow and Montreal.
