Southwest Airlines is deepening its global reach once again, announcing on December 17, 2025, a new partnership with Turkish Airlines that will allow customers to book one-ticket journeys linking Southwest’s vast U.S. domestic network with Turkish Airlines’ globe-spanning operation via Istanbul.

The deal, which Southwest says is its sixth international partnership unveiled this year, is set to begin in early January 2026 and underscores how the Dallas-based carrier is leaning on overseas partners rather than flying long-haul international routes itself.

More News:

Details of the New Southwest–Turkish Partnership

Under the agreement, travelers will be able to purchase single-ticket itineraries that combine domestic segments on Southwest with transatlantic and onward flights on Turkish Airlines.

The tickets will be sold primarily through Turkish Airlines, as well as through travel agents and major online booking platforms, starting in 2026. That structure means a traveler in, for example, Denver could check in once and have bags checked through to Istanbul and beyond, even though the long-haul leg is operated entirely by Turkish Airlines.

Southwest and Turkish Airlines share service at ten U.S. airports, which will function as the primary gateways feeding Turkish’s Istanbul hub. Southwest has not formally listed all ten in its press materials, but route map analysis by aviation outlets points to major gateways including Boston, Washington Dulles, Atlanta, Miami, Detroit, Chicago O’Hare, Denver, Los Angeles, San Francisco, and Seattle.

At these airports, international passengers will be able to connect between the two carriers on aligned schedules within a single reservation and with coordinated minimum connection times.

The partnership is being structured as an interline arrangement rather than a full codeshare or alliance membership. That means flights will generally continue to carry each airline’s own designator code, but passengers will experience a single booking path, harmonized itineraries, and through-checked baggage on eligible connections.

For Southwest, which has historically eschewed global alliance membership, the model offers many of the customer-facing benefits of broader integration without the complexity of deep joint ventures or metal-neutral partnerships.

A Sixth International Partner in a Transformative Year

The deal with Turkish Airlines is the sixth international partnership Southwest has unveiled in 2025, capping what has become one of the most internationally focused years in the carrier’s history.

Earlier this year, Southwest announced new or expanded interline arrangements with Icelandair for European connections, Philippine Airlines and EVA Air for Asia-bound travelers, Hahnair to place Southwest inventory in global distribution systems for travel agencies, and, most recently, Germany’s Condor for additional transatlantic options via Frankfurt.

In each case, the common thread has been the creation of single-ticket itineraries that leverage Southwest’s dense domestic network to funnel travelers into long-haul flights operated by foreign partners.

The partnerships knit together a broad swath of new one-stop routings, from mid-sized cities in the United States to destinations across Europe, Asia, the Middle East, and Africa. By adding Turkish Airlines, which has one of the largest international networks in the world, Southwest is significantly expanding that map once again.

For Southwest, the year’s partnership spree represents a strategic pivot from being a largely domestic low-cost carrier with limited international flying in the Americas to acting as a feeder and distribution powerhouse for global airlines.

Executives have framed these agreements as a way to increase the relevance of Southwest’s domestic network, capture new revenue streams from inbound and outbound international travelers, and raise global brand awareness without incurring the cost and operational complexity of operating widebody aircraft or establishing long-haul bases.

What the Tie-Up Means for Travelers

For customers, the headline change will be the ability to book itineraries that start on Southwest in the United States and continue on Turkish Airlines to Istanbul and onward destinations, all under a single ticket and a single fare construction.

That simplifies booking and reduces the risk that a misconnection on the domestic leg could strand a traveler, since the entire itinerary is protected within one reservation handled by Turkish and its distribution partners.

International travelers arriving from Turkish Airlines flights into shared U.S. gateways will be able to connect directly onto Southwest flights serving dozens of additional cities, often with high-frequency schedules and point-to-point options that bypass traditional hub congestion.

For cities that Southwest serves but Turkish does not, the combination opens up new one-stop access to Istanbul and Turkish’s global network, including major markets across Europe, the Gulf, North Africa, East Africa, South Asia, and Southeast Asia.

The partnership also has implications for baggage handling and customer support. Checked baggage will be tagged through from the origin to the final destination on eligible itineraries, with handoffs between Turkish Airlines ground teams and Southwest at gateway airports.

In the event of delays or disruptions, passengers on a single-ticket routing should receive rebooking support across both carriers, rather than having to navigate separate reservations independently.

Turkish Airlines’ Global Network as a New Gateway

Turkish Airlines brings a powerful global footprint to the agreement. From its hub at Istanbul Airport, the airline serves more than 350 destinations in 132 countries, a reach that ranks among the most extensive in the industry.

The carrier’s network strategy positions Istanbul as a natural crossroads between Europe, Asia, Africa, and the Middle East, with banks of connecting flights timed to facilitate smooth transfers in both directions.

By plugging into that network, Southwest effectively gains access to hundreds of onward destinations without operating a single new international flight beyond its existing footprint in the Americas.

Travelers connects from Southwest’s domestic routes to Turkish flights headed to cities such as Dubai, Nairobi, Delhi, Bangkok, and countless secondary markets across Europe and Central Asia, often with competitive one-stop journey times from many U.S. origins.

Turkish Airlines also benefits from improved access to U.S. origin-destination traffic in markets where it does not operate its own feeder service. Southwest’s strong presence in secondary and mid-sized U.S. cities creates new source markets for Turkish’s long-haul network. For Turkish, the deal is a way to deepen its presence in North America without adding numerous new domestic partnerships or flights of its own.

Strategic Shift for Southwest: Partnerships Over Widebodies

The Turkish Airlines agreement highlights a broader strategic choice by Southwest to pursue global connectivity through partnerships rather than by entering the long-haul, widebody market.

The airline has long been known for its single-fleet model built around Boeing 737 aircraft, a strategy that simplifies training, maintenance, and scheduling while keeping costs low. Adding long-haul aircraft such as Boeing 787s or Airbus A350s would introduce significant complexity and require a different operating model.

Instead, Southwest is choosing to “borrow” global reach from partners that already operate sophisticated long-haul networks. Interline and similar agreements allow Southwest to remain focused on what it does best: high-frequency, point-to-point domestic flying within the United States and nearby international leisure markets such as Mexico and the Caribbean. Long-distance flying between continents is left to carriers like Turkish, which have built their businesses around those missions.

Industry analysts say the approach could allow Southwest to capture a share of international travel revenue while preserving its cost advantage. It also aligns with the carrier’s broader product evolution.

Beginning January 27, 2026, Southwest plans to introduce assigned seating and extra legroom options, alongside a redesigned cabin, moving away from its long-standing open-seating model. Those enhancements are expected to make Southwest more competitive in attracting higher-yield international transfer passengers who may be more sensitive to comfort and seat selection.

Impact on the Competitive Landscape

The new deal will add another competitive wrinkle to an already dynamic transatlantic marketplace. U.S. legacy carriers such as American, Delta, and United have long relied on their alliances and joint ventures with European partners to dominate long-haul traffic flows.

Southwest, which remains outside of the main global alliances, is now carving out an alternative path, connecting with nonaligned or differently aligned carriers like Turkish, Condor, and Philippine Airlines to build a patchwork of bilateral relationships.

For competing airlines, the combination of Southwest’s scale in domestic U.S. flying and Turkish’s reach across Europe, Africa, and Asia could draw passengers away from traditional hub-and-spoke itineraries marketed by full-service U.S. carriers and their European partners.

It may also particularly impact flows in markets where Turkish is strong, such as connections between North America and secondary cities in Eastern Europe, the Caucasus, Central Asia, and parts of Africa that are not served nonstop by U.S. or Western European airlines.

At the same time, the partnership underscores how global connectivity is no longer limited to the three large alliances. For travelers, that can translate into more choice, varied price points, and new routing options that combine low-cost and full-service carriers in ways that were previously more difficult to book on a single ticket.

What Happens Next for Customers and Agents

Southwest and Turkish Airlines have indicated that the partnership will go live in early January 2026, though an exact start date for the first ticket sales has not been publicly detailed beyond “next year.”

Travel advisors and corporate travel managers will need to update booking practices to incorporate the new routings, particularly for clients based in U.S. cities heavily served by Southwest that are looking for efficient one-stop access to Istanbul or beyond.

Initially, ticketing will be handled through Turkish Airlines’ own channels and via global distribution systems used by travel agencies, with Southwest segments appearing as part of combined itineraries.

Over time, industry observers will be watching for possible expansion in how and where the joint itineraries can be purchased, and whether the two airlines choose to deepen cooperation into elements such as shared frequent flyer earning or coordinated customer recognition, areas that have not yet been formally announced.

Both carriers are expected to roll out additional communication in 2025 and early 2026 to educate travelers about the new options, connection processes at U.S. gateways, and any special check-in or baggage procedures.

With multiple other partnerships also launching around the same time, Southwest’s front-line staff and customer communication channels will play an important role in helping passengers understand a more complex, globally connected product than the airline has offered in the past.

FAQ

Q1. When will the Southwest and Turkish Airlines partnership begin operating for travelers?
The partnership is scheduled to begin in early January 2026, with one-ticket itineraries linking U.S. cities on Southwest to Istanbul and beyond on Turkish Airlines.

Q2. How will passengers book itineraries that combine Southwest and Turkish Airlines flights?
Customers will be able to book combined itineraries primarily through Turkish Airlines’ sales channels, as well as through travel agents and major online booking platforms that participate in the agreement.

Q3. Will I be able to check my bags through from my U.S. origin to my final destination overseas?
On eligible single-ticket itineraries that include both carriers, checked baggage will be tagged from the origin to the final destination, with handoffs managed between Southwest and Turkish Airlines at the gateway airport.

Q4. Which U.S. airports are expected to serve as gateways for the new partnership?
The partnership will use ten shared U.S. airports where both airlines operate. Industry analysis points to major gateways such as Boston, Washington Dulles, Atlanta, Miami, Detroit, Chicago O’Hare, Denver, Los Angeles, San Francisco, and Seattle, although Southwest has not formally listed each airport in public documents.

Q5. Does this mean Southwest will start flying to Istanbul or operating long-haul flights?
No. All transatlantic and onward long-haul flights in this partnership will be operated by Turkish Airlines, while Southwest will continue to operate domestic segments and near-international service within its existing 737-based fleet.

Q6. How many international destinations will become reachable through this arrangement?
Through Turkish Airlines’ network from Istanbul, travelers will be able to connect to more than 350 destinations in 132 countries, significantly expanding the range of one-stop itineraries available from many U.S. cities served by Southwest.

Q7. Will Southwest’s Rapid Rewards members earn points on Turkish Airlines flights under this partnership?
As of the announcement date, the airlines have not detailed frequent flyer reciprocity, and any earning or redemption options across programs would depend on future agreements not yet publicly confirmed.

Q8. How does this agreement relate to Southwest’s other foreign partnerships announced in 2025?
The Turkish Airlines deal is Southwest’s sixth international partnership this year and follows similar interline arrangements with carriers such as Condor, Icelandair, Philippine Airlines, and EVA Air, all designed to create one-ticket connections between Southwest’s U.S. network and long-haul international flights.

Q9. Will assigned seating or extra legroom options be available on Southwest flights linked to Turkish itineraries?
Southwest has said that from January 27, 2026, it will introduce assigned seating and extra legroom options on its own flights. Those enhancements are expected to be available regardless of whether a customer is traveling on a standalone Southwest ticket or as part of a Turkish Airlines–issued itinerary.

Q10. Where can travelers get support if they face disruptions on a mixed Southwest and Turkish itinerary?
For itineraries issued on a single ticket, the airline that issued the ticket, typically Turkish Airlines or the selling travel agent, will be the primary point of contact, but both carriers are expected to coordinate rebooking and customer assistance when delays or cancellations affect connecting flights within the combined itinerary.