Five major airlines in the United States operate Boeing 737 MAX aircraft: United Airlines, Southwest Airlines, American Airlines, Alaska Airlines, and Allegiant Air. Delta Air Lines recently joined this group by ordering MAX 10s at the Farnborough Air Show in 2023. Allegiant Air is the latest to start operating these planes with its acquisition of the 737 MAX 8-200.
Southwest Airlines has established itself as a prominent operator of the Boeing 737 series. With a fleet of 243 MAX 8 aircraft, it holds the largest number of these planes in the U.S. The airline continues to expand its fleet with an additional order for 188 more MAX aircraft and another purchase agreement for 286 MAX 7s. However, deliveries of these models have been delayed due to pending certification from the Federal Aviation Administration (FAA).
United Airlines follows closely behind with a fleet comprising both MAX 8 and MAX 9 variants totaling 188 aircraft. The airline began receiving its first deliveries in early January of 2019 and has continued to expand its collection steadily over recent years. Despite having a significant number already operational, United plans further expansion with orders for over three hundred more planes including additional units from each variant currently on backorder.