Southwest Airlines leads global low-cost carriers in number of operated Boeing 737 MAX aircraft

In terms of other aircraft types operated by these carriers, Southwest maintains an all-Boeing narrowbody fleet that includes older models like the Boeing 737-700 (329 units) and Boeing 737-800 (203 units). The airline previously acquired some Boeing 717-200s through its purchase of AirTran Airways but subleased them to Delta Air Lines due to its single-fleet strategy.

Ryanair’s broader fleet consists mainly of Boeing aircraft as well: it operates a total of 619 planes including both owned and wet-leased jets. Its active roster features nearly four hundred Boeing 737-800s with an average age just over thirteen years; some are more than twenty-one years old. Additionally, Ryanair flies one wet-leased Boeing 737-700 and recently began operating twenty-six Airbus A320-200s leased from Lauda Europe.

The popularity of the Boeing 737 MAX among airlines stems from several design improvements over earlier generations. These include aerodynamic upgrades like split-tip winglets, new landing gear for increased ground clearance, glass cockpit technology, fly-by-wire spoilers, and more efficient CFM International LEAP engines that provide about a fourteen percent reduction in fuel burn compared to previous engines.

The first commercial flight using a Boeing 737 MAX took place in May 2017 with Malindo Air (now Batik Air Malaysia). Since then, nearly two thousand units have been delivered globally. Among all operators worldwide, Southwest Airlines holds the largest active fleet as well as the biggest outstanding order for additional planes—427 more on order—while United Airlines follows closely behind with both current inventory and future deliveries.

Other major US-based operators include United Airlines (238 aircraft), Alaska Airlines (98), and American Airlines (79). Internationally, carriers such as Aeroméxico (72), flydubai (68), GOL Linhas Aéreas Inteligentes (58), Air Canada (57), WestJet (56), Lion Air, Akasa Air, and SpiceJet also maintain sizable orders or fleets of this aircraft type.

According to ch-aviation data referenced throughout industry reporting—including information about current fleets and pending orders—these figures reflect ongoing trends among leading low-cost carriers investing heavily in next-generation narrowbody jets like the Boeing 737 MAX.