The first half of 2026 has been challenging for airlines around the world, with fuel prices rising sharply following the 2026 Iran Crisis. As a result, the International Air Transport Association (IATA) halved its profitability forecast for the global airline industry. US airlines have not been immune to these pressures, with most major carriers reporting lower profits during the first six months of the year than in the same period a year earlier.

Profitability can be measured in several ways, with some metrics better suited than others to comparing airlines. Absolute profit figures often say more about the size of a carrier than the efficiency of its operations. A more useful measure is therefore operating margin. An airline’s operating profit, often referred to as earnings before interest and tax (EBIT), reflects how much it earns from operations before financing costs and taxes.

Expressing operating profit as a percentage of revenue makes it possible to compare airlines of very different sizes based on how effectively they turn revenue into profit. While Delta Air Lines and United Airlines generated the highest absolute operating profits among US carriers in the first half of 2026, some readers might be surprised by which much smaller airline actually achieved the highest operating margin.

This ranking includes only airlines that sell and operate passenger flights under their own brands. SkyWest Airlines therefore does not qualify, despite reporting an impressive 13.2% operating margin during the first half of 2026. The regional carrier operates flights on behalf of the big three US airlines and Alaska Airlines, giving it a fundamentally different business model from the airlines included below.

5

American Airlines

1.3% Operating Margin

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American Airlines reported a razor-thin 1.3% operating margin for the first half of 2026, compared to 3.2% in the same period a year earlier. This margin translated into an operating profit of $405 million on over $30 billion in revenue for the Fort Worth-based carrier as the airline continues its efforts to catch up with Delta and United.

To close the profit gap with its largest competitors, American is rebuilding its relationship with travel agencies and corporate accounts, while doubling down on premiumization to generate more premium revenue. For the second quarter of 2026, revenue from premium passengers increased 13.4%, and the carrier continues to invest in its premium products.

Last month, the airline announced it would grow premium seating on its narrowbody departures from 25% to 40% over the coming years. This growth in premium capacity has already been ongoing for some time now, in the company’s long-haul fleet. Newly delivered aircraft, Boeing 787 and Airbus A321XLR all come in premium-heavy configurations featuring the new Flagship Suite product with privacy doors. The Boeing 777 fleet is currently being retrofitted with the new seat.

With the arrival of additional aircraft, American is also continuing to grow its long-haul network and is simultaneously working to improve hub efficiency. At Dallas/Fort Worth International Airport (DFW), the airline reorganized its arrival and departure banks to improve hub connectivity. At the same time, Philadelphia International Airport(PHL) is being optimized to improve transatlantic connectivity, while Miami remains central to American’s Latin American competitive advantage.

4

Southwest Airlines

3.9% Operating Margin

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Dallas-based Southwest Airlinesachieved a significantly better result in the first months of the year compared to the previous year, when the airline effectively broke even with an operating result of just $2 million. This year, the carrier generated $15.7 billion in revenue and an operating profit of $615 million. This translates into a 3.9% operating margin.

These results come as the airline completely overhauled its identity and operating model in recent years. For years, Southwest offered a relatively homogeneous product, along with a generous free baggage policy and an open seating policy. Since the beginning of 2026, however, the airline has started allocating seats to passengers and has begun offering an extra-legroom product.

In 2025, the company has already revised its baggage charges and fare structure. According to Southwest, these changes are directly contributing to higher passenger yields and incremental revenue, translating into positive margins.

Looking ahead, the carrier is trying to capture more “premium” revenue by appealing to business travelers and other price-insensitive passengers, rather than relying heavily on its traditional leisure passengers. To achieve this, Southwest is retrofitting its aircraft with new, improved seats and Starlink WiFi. From 2027, the Texas carrier will even open its own airport lounges. At the same time, the airline is also redesigning its loyalty program and launching new code-share partnerships with several international airlines.

3

Delta Air Lines

6.4% Operating Margin

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Delta Air Lines generated an operating margin of 6.4% from its core airline operations during the first half of 2026, excluding its refinery results. This translated into an operating profit of just over $2 billion on $31.9 billion in airline revenue. The result was considerably weaker than the roughly 9.4% margin achieved during the same period a year earlier.

Despite this decline, Delta continues to benefit from one of the strongest premium and loyalty propositions among US airlines. In the first half of 2026, premium ticket revenue increased 16% to $12.3 billion, slightly exceeding economy class revenue. This reflects the carrier’s long-running strategy of generating a larger share of revenue from higher-yielding passengers rather than relying on economy cabin volume.

The airline continues to support this strategy through further investments in its fleet and onboard product. Delta is expanding its Airbus A321neo fleet and continues to operate premium-heavy configurations on some of its newest narrowbodies, while its long-haul aircraft offer Delta One, Premium Select, and Comfort products across a growing number of markets.

2

United Airlines

6.5% Operating Margin

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Chicago-based United Airlines achieved a 6.5% operating margin during the first half of 2026, narrowly exceeding Delta’s core airline operations. The carrier generated $32.3 billion in revenue and an operating profit of almost $2.1 billion, compared to a 6.8% margin during the same period a year earlier. However, United’s reported operating profit was supported by several special items, including gains from aircraft sale-leaseback transactions.

United’s profitability is supported by an increasingly premium-heavy transatlantic network and its position as the largest US airline internationally. Premium revenue continued to grow strongly during the second quarter, while United also reported higher revenue from contracted business travelers.

The carrier has spent much of the past several years expanding beyond the traditional major European gateways, using its hubs at Newark Liberty International Airport (EWR) and Washington Dulles International Airport (IAD) to connect passengers to a growing number of secondary destinations alongside established markets such as London, Frankfurt, and Paris.

At the same time, United continues to increase the number of premium seats available across this international network. The airline is introducing a new premium-heavy Boeing 787-9 configuration featuring 99 premium seats, including the new Polaris Studio suites alongside 56 regular Polaris business class seats. United’s first Airbus A321XLR is also expected to enter service later this year before launching international flights, giving the carrier another aircraft capable of serving thinner long-haul markets with dedicated Polaris and Premium Plus cabins.

1

Allegiant Air

7.4% Operating Margin

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The most profitable airline in the United States for the first half of 2026 was Allegiant Air. The leisure-focused carrier generated $1.5 billion in revenue and roughly $111 million in operating profit. This translates into a 7.4% operating margin, despite its small size compared to the other airlines on this list.

Compared to most US airlines, Allegiant operates a somewhat unusual business model resembling that of European leisure carriers. The Las Vegas-based carrier has traditionally focused on linking smaller and mid-sized communities directly with leisure destinations, often avoiding head-to-head competition with larger competitors.

Moreover, Allegiant is willing to adapt its schedules to leisure travel patterns, increasing frequencies during periods of strong demand rather than operating the same schedule throughout the year. This strategy was evident in its latest quarterly results. During the second quarter, Allegiant reduced capacity by 6.8% while unit revenue increased by 24.6% year over year.

Strengthening Allegiant’s position in the US leisure market in the coming years is its acquisition of Sun Country Airlines, creating a combined group with around 195 aircraft, more than 650 routes, and approximately 22 million annual passengers. The acquisition complements Allegiant’s strong presence in smaller and mid-sized domestic markets with Sun Country’s sizable operation at Minneapolis-St. Paul International Airport (MSP), while also providing access to leisure destinations across Mexico, Central America, Canada, and the Caribbean.

The transaction also diversifies Allegiant beyond scheduled leisure travel. Sun Country operates cargo flights for Amazon Prime Air and has an established charter business serving customers including casinos, sports teams, and the US government. For now, Sun Country continues to operate separately under common ownership, but Allegiant expects the two carriers to eventually transition to a single operating certificate.