WestJet was founded in 1996 by Clive Beddoe, Mark Hill, Tim Morgan and Donald Bell, four Calgary entrepreneurs who saw an opportunity to provide low-fare air travel across western Canada . The team researched other successful airlines in North America - in particular low-cost carriers. Following the primary examples of Southwest Airlines and Morris Air, they determined that a similar model could be successful in Western Canada.

On February 29, 1996, WestJet commenced flight operations with 220 employees and three aircraft to the cities of Vancouver, Kelowna, Calgary, Edmonton and Winnipeg. Later in 1996, WestJet added Victoria , Regina and Saskatoon to its western route network. In 1997, WestJet began service to Abbotsford/Fraser Valley, and in 1999 WestJet added Thunder Bay, Prince George and Grande Prairie to its service area.

1999 marked a major milestone for WestJet, completing its Initial Public Offering of 2.5 million common shares in July of that year. It was an exciting day for all WestJetters, representing the achievement of a key business goal and raising the necessary capital for expansion of the company into the coming years. With the help of lead underwriters, CIBC World Markets, and the dedicated executive team, WestJet made a successful transition to a public company. The capital raised from the offering was used for the purchase of additional aircraft, as well as construction of a new Head Office and Hangar facilities in Calgary.

WestJet's fleet of Next-Generation Boeing 737 aircraft featuring new aircraft with leather seats and more legroom commenced transborder service in the fall of 2004. The cities of Los Angeles, San Francisco, Phoenix, Fort Lauderdale, Tampa, Orlando and New York were added to the new U.S. route network. Service to Palm Springs, Maui, Honolulu and Fort Myers (seasonal) began in 2005.

Celebrating over ten years in business, WestJet now employs over 6,000 people and has carried over 9.4 million guests. Its current 23 Canadian destinations include Victoria, Comox, Vancouver, Abbotsford/Fraser Valley, Prince George, Kelowna, Grande Prairie, Calgary, Edmonton, Fort McMurray, Saskatoon, Regina, Winnipeg, Thunder Bay, London, Hamilton, Toronto, Ottawa, Montréal, Moncton, Charlottetown, Halifax and St. John's. Its 10 current American destinations are Honolulu, Maui, Los Angeles, Palm Springs (seasonal), Las Vegas, Phoenix (seasonal), Tampa , Orlando, Fort Myers (seasonal) and Fort Lauderdale, West Palm Beach (seasonal). Internationally, WestJet flies seasonal service to Nassau, Bahamas .