Founded as a low-cost alternative to Air Canada, Westjet has gradually established itself as a standard airline offering follow-on flights. It is based at Toronto, Calgary and Vancouver airports, but also flies from other Canadian airports.

The company's fleet consists primarily of Boeing 737s, with short-haul routes operated by propeller-driven De-Havillands and some routes to London by older Boeing 767s. In total, 120 aircraft fly for Westjet.