Southwest international expansion moves forward

Published on Aug 22, 2025, 2:01 pm CDT

6 min read

Southwest Airlines is weighing a broader push overseas, telling employees it is exploring new international destinations that can be served with its Boeing 737 fleet. The move follows a May filing with the U.S. Department of Transportation seeking blanket authority to serve countries covered by Open Skies agreements, plus a step-up in international partnering through an interline with Icelandair that expanded in July. Contract talks with pilot and flight attendant unions are underway to enable the operational changes required for longer-haul flying.

Key Points

Why it matters: Southwest could evolve from a mostly North American carrier to a wider international competitor.
Travel impact: New one-stop and nonstop options may appear from major Southwest stations with customs facilities.
What's next: DOT action on Southwest's Open Skies application, then route announcements if labor terms align.
Labor talks: Discussions with SWAPA and TWU 556 cover scheduling and pay for extended international operations.
Partnerships: An expanded Icelandair interline now connects through six U.S. airports for transatlantic access.

Snapshot

Southwest's international footprint has long focused on Mexico, the Caribbean, and Central America. In May 2025, the airline applied to the U.S. DOT for blanket authority to serve any Open Skies country, a procedural step that removes case-by-case filings. Executives have since told employees the company is studying additional overseas flying using its 737 aircraft, and industry reports describe early conversations with pilot and flight attendant unions. Near-term connectivity is already improving through a broadened interline with Icelandair, which now offers more U.S. gateways for one-ticket journeys to Europe. Timing and targets remain unannounced, but the direction is clear, Southwest is building optionality for international growth.

Background

Southwest has steadily added near-international routes since opening international facilities at key stations a decade ago, but it remains primarily a domestic operator. The airline's 737-only fleet simplifies operations, yet it also limits range compared to long-haul aircraft used for transoceanic flying. To gain flexibility, Southwest filed for blanket Open Skies authority on May 13, 2025, signaling interest in a wider set of countries without committing to specific markets. In parallel, the carrier introduced an interline with Icelandair, creating bookable connections between Southwest's U.S. network and Icelandair's European destinations through six U.S. gateways. Management has also indicated willingness to evolve the business model to stay competitive, as it evaluates premium touches and broader network options.

Latest Developments

DOT filing positions Southwest for Open Skies growth

On May 13, 2025, Southwest asked the U.S. DOT for a certificate and exemptions allowing scheduled foreign air transportation between the United States and countries with Open Skies agreements. This blanket authority reduces administrative friction when launching service to eligible nations, and the filing explicitly frames operations on Boeing 737 variants that meet current noise standards. The DOT docket shows the request and service list, a routine precursor for carriers contemplating new international markets. Approval would not force expansion, but it would allow Southwest to act quickly when network, aircraft, and crew resources align.

Union talks pave the way for longer-haul flying

Southwest has told employees it is studying overseas expansion using 737s and has opened focused talks with the Southwest Airlines Pilots Association and Transport Workers Union Local 556. These discussions address rest rules, pay, scheduling, and overnight patterns tied to international operations. Trade publications and local reporting underscore that contract adjustments are a practical requirement before adding longer-stage international flying. The airline describes the scope as limited, centered on enabling new destinations rather than wholesale changes to fleet strategy.

Interline with Icelandair expands one-ticket options

Southwest's interline with Icelandair, first announced last year, broadened on July 14, 2025. Customers can connect on a single itinerary through Baltimore, Nashville, Denver, Orlando, Pittsburgh, and Raleigh-Durham, linking Southwest's domestic feed to Icelandair flights via Keflavik. While this is not the same as Southwest operating its own flights across the Atlantic, it materially improves access for travelers in Southwest cities. The arrangement also illustrates a more partnership-friendly posture that could complement any future Southwest-operated international growth.

Analysis

For travelers, the headline is flexibility. A DOT grant would allow Southwest to move faster when opportunities arise, particularly in mid-range international markets reachable by 737. That points first to deeper coverage in the Americas and selected leisure points where customs facilities, slots, and local demand line up with Southwest's network strengths. The airline's station footprint at larger international gateways, including Baltimore, Orlando, Pittsburgh, Raleigh-Durham, Denver, and Nashville, provides logical springboards, especially where it can leverage strong domestic feed.

Fleet constraints will shape choices. Operating only 737s keeps costs low and processes consistent, but it narrows the radius for viable nonstop service. Southwest can still open meaningful new routes, yet very long-haul sectors would be challenging without different aircraft, so the most realistic path combines incremental 737 expansion with partnerships that extend reach. The expanded Icelandair interline is an example, offering immediate utility to Europe without new metal. The gating factors now are labor agreements, aircraft availability, airport facilities, and competitive responses. If those align, customers should see a steady cadence of announcements rather than a single dramatic reveal, with schedules built to protect turn times, reliability, and the carrier's brand promise.

Final Thoughts

Southwest is methodically setting the table for broader overseas service, using regulatory flexibility, targeted labor talks, and partnerships to keep options open. Travelers should expect incremental, well-timed additions that fit the 737 playbook, complemented by one-ticket access through partners for farther-flung destinations. As approvals and agreements fall into place, the next phase will be specific city pairs. Until then, the signal is unmistakable, the carrier is preparing for growth beyond its traditional footprint, and that preparation could soon translate into real choices for you. The direction of travel is clear, Southwest international expansion.