The new route will be operated with a Boeing Dreamliner aircraft and is the only scheduled service between the two cities.
WestJet’s new Calgary service will also offer onward connections to 24 destinations including Vancouver and Las Vegas.
“We have forged a strong bond and friendship with WestJet and we are delighted to welcome its new direct service between Calgary and Dublin Airport,” said Dublin Airport's managing director, Vincent Harrison.
“Dublin Airport is now connected to six Canadian cities which means that this year is set to be our busiest year ever for travel between Dublin and Canada.
"I have no doubt this new service will be popular in both directions for business and leisure passengers."
WestJet’s chief commercial officer, Arved von zur Muehlen, commented: “With the launch of our third transatlantic Dreamliner flight, WestJet adds to our exceptional growth into and out of Calgary, where we remain the airline with the most destinations and departures.
"With more than 4.5 million Canadians claiming Irish heritage, we are pleased to be providing our guests with easy access to all the cultural, economic and social ties between Western Canada and Ireland.”
WestJet, which is Canada’s second largest airline, is headquartered in Calgary and operates about 725 flights daily to 105 destinations.
Dublin was WestJet’s first ever transatlantic destination, as the airline launched its Dublin-St John’s Newfoundland service in the summer of 2014.
The airline switched its services between Dublin and St John’s to a six times weekly service to Halifax in April this year.
The new Dublin-Calgary route will operate from Dublin three times per week on Sunday, Monday and Thursday.
Calgary is one of six Canadian destinations served directly from Dublin Airport this summer; joining Toronto, Montréal, Vancouver, Halifax and Hamilton, Ontario.