Complete Southwest Japan Flights Guide [2026]

Last Updated on August 26, 2026 by Daniel Globe

Planning a trip to Japan and wondering whether Southwest Airlines can get you there? Southwest does not operate its own flights across the Pacific to Japan, but its interline partnership with All Nippon Airways (ANA) gives travelers a way to combine a Southwest domestic flight with an ANA-operated flight to Japan on one partner itinerary. The important details are where you connect, where you book, and which airline’s rules apply along the way.

Southwest Airlines International Destinations

Southwest built most of its network around U.S. domestic travel, but the airline has operated its own international flights since July 2014. Its international flying focuses on relatively close destinations in Mexico, Central America, and the Caribbean rather than long-haul transpacific routes.

That distinction matters when you search for Japan. A Southwest aircraft will not take you from the United States across the Pacific. Instead, Southwest is expanding its global reach through interline agreements that connect its domestic network with international airlines.

Popular Southwest-operated international destinations include places such as Cancun, Aruba, and Montego Bay. Japan works differently because the long international portion is operated by a partner airline rather than Southwest.

Southwest Airlines and Asian Markets

Southwest has increasingly used interline partnerships to connect its network with destinations beyond the range of its own aircraft. ANA became one of those partners in March 2026, giving travelers access to Japan and other ANA destinations while still using Southwest for eligible U.S. connecting segments.

According to Southwest’s official airline-partner information, Southwest and ANA began offering bookable partner travel on March 10, 2026. Their shared gateways are Honolulu, Los Angeles, San Francisco, and Seattle.

How Southwest–ANA Connections to Japan Work

Your Southwest portion takes you to one of the shared U.S. gateway airports. ANA then operates the long-haul flight to Japan. The following table reflects ANA’s published March 29–October 24, 2026 international schedule and may change after that schedule period.

You can confirm the latest operating dates directly on ANA’s international route information page.

Osaka, Nagoya, Sapporo, Fukuoka, Okinawa, and other Japanese destinations can still be possible on a partner itinerary, but do not assume ANA flies nonstop to each city from Southwest’s shared U.S. gateways. In many cases, you will first arrive in Tokyo and continue on another ANA flight or another eligible connection.

The advantage of an interline itinerary is that the Southwest and ANA flights can be issued together rather than requiring you to create two unrelated reservations. That can simplify the journey, especially if your home airport does not have a nonstop Japan flight.

Benefits and Trade-Offs of a Southwest–ANA Itinerary

The main benefit is network reach. A traveler starting in a city served by Southwest may be able to fly Southwest to HNL, LAX, SFO, or SEA and continue with ANA without arranging an entirely separate self-transfer itinerary.

Another benefit is the coordination that comes with interlining. Southwest defines interlining as an agreement that coordinates passengers and checked baggage across an itinerary involving two or more airlines. That is generally safer and easier to manage than independently booking unrelated flights with a short connection.

However, a Southwest–ANA itinerary is not automatically the cheapest option. ANA, Japan Airlines, United, Delta, American, and other carriers may offer competitive nonstop or one-stop fares. Compare the final price, baggage allowance, seat selection, connection length, refund rules, and total travel time before choosing.

Southwest’s usual fare benefits also should not be assumed to apply to the entire ticket. On a partner reservation, Southwest says the partner carrier’s fare rules apply to voluntary changes and cancellations. Current Southwest fare rules also distinguish between Basic and higher fare bundles, so the old idea that every Southwest ticket can simply be changed under identical conditions is no longer accurate.

How to Book a Southwest–ANA Trip to Japan

As of August 2026, Southwest’s own support information says partner itineraries are booked through its partner airlines’ websites and channels. Southwest also says booking partner itineraries on Southwest.com will be offered in the future.

1. Start with ANA or an eligible travel agency. Search your actual U.S. origin and final Japanese destination rather than searching only from the gateway.
2. Look for an itinerary containing both Southwest and ANA flights. Your domestic segment may be operated by Southwest, followed by an ANA flight from HNL, LAX, SFO, or SEA.
3. Confirm that the flights are on one partner reservation. Do not assume two separately purchased tickets receive the same interline protection.
4. Review the operating carrier for every segment. Seat, baggage, check-in, onboard service, and other policies can differ by airline.
5. Read the fare conditions before paying. Pay particular attention to change fees, refunds, flight credits, baggage allowance, and missed-connection handling.
6. Add your Rapid Rewards number where eligible. Southwest says Rapid Rewards members can earn qualifying points on the Southwest-operated portion of eligible partner reservations.

For current partner-booking rules, see Southwest’s interlining guidance and Southwest’s partner-itinerary information.

Rapid Rewards points do not turn the ANA-operated transpacific flight into a Southwest earning flight. Southwest currently awards Rapid Rewards credit on eligible Southwest-operated portions of partner itineraries according to its partner earning rules. If ANA mileage earning matters to you, separately check the ANA Mileage Club rules for the ANA fare class you are purchasing.

Tips for Flying to Japan on a Partner Itinerary

Choose your gateway carefully. The shortest domestic connection is not always the best connection. Compare connection time, terminal changes, the ANA departure schedule, and the consequences of a delay before selecting HNL, LAX, SFO, or SEA.

Check in with the airline operating your first flight. Southwest’s current instructions say partner-itinerary travelers should check in with the operating carrier of the first segment. If your first flight is Southwest, use Southwest check-in. If ANA operates the first segment, start with ANA.

Verify baggage rules before arriving at the airport. Southwest says the operating carrier’s policies generally apply on partner itineraries, and some Southwest checked-bag benefits do not apply to flights booked through partner carriers. Do not assume your normal Southwest baggage entitlement automatically carries over.

Allow a comfortable connection. International connections involve more variables than a normal domestic Southwest transfer. A longer connection can provide useful protection against delays, terminal transfers, document checks, and baggage issues.

Check the exact Tokyo airport. Haneda (HND) is closer to central Tokyo, while Narita (NRT) is farther from central Tokyo but remains an important international gateway. If you have an onward domestic connection, the airport shown on every segment matters.

Compare nonstop alternatives. United, Delta, American, Japan Airlines, and ANA operate nonstop U.S.–Japan service from selected U.S. gateways. Schedules change, so compare current flights for your dates rather than assuming a particular route operates year-round.

What to Know Before You Book

The Southwest–ANA arrangement is useful, but it is important to understand what it is. Southwest is not becoming a transpacific airline, and ANA’s Japan flight is not a Southwest-operated flight. You are combining flights from two airlines under an interline partnership.

That structure affects almost every practical part of the trip. The airline operating each segment controls many of the onboard and airport rules for that flight. The ticketing partner’s fare conditions can affect voluntary changes and refunds. Check-in starts with the airline operating your first flight, and Southwest-specific elite, credit-card, seating, or baggage benefits may not work the same way on a partner-issued reservation.

Before paying, compare these five items:

• Total fare including baggage and seat charges.
• Total travel time and gateway connection length.
• Whether every segment appears on the same partner ticket.
• Change, cancellation, refund, and missed-connection rules.
• Loyalty earning and baggage benefits on each operating carrier.

For many Southwest flyers, the ANA partnership creates a useful new way to reach Japan from cities that do not have convenient nonstop service. For others, a nonstop ANA, JAL, United, Delta, or American itinerary may still provide the better combination of schedule, price, and simplicity.

Frequently Asked Questions

Conclusion

Southwest Airlines still does not fly its own aircraft to Japan, but its ANA interline partnership makes Japan accessible from more of Southwest’s U.S. network. The four shared gateways are Honolulu, Los Angeles, San Francisco, and Seattle, with ANA handling the transpacific portion. The most important current detail is booking: as of August 2026, partner itineraries are sold through partner channels rather than Southwest.com. Compare the complete fare, connection time, baggage rules, change conditions, and nonstop alternatives before deciding which itinerary offers the best overall trip.

Sources

1. Southwest Airlines — Airline Partners — ANA partnership launch date, booking channels, and shared gateway airports.
2. Southwest Airlines — Interlining Partners — current partner list, interline definition, Southwest.com booking status, and Rapid Rewards partner earning.
3. Southwest Airlines — Flying on a Partner Itinerary — operating-carrier policies and partner-reservation guidance.
4. Southwest Airlines — Online Check-In — first-operating-carrier check-in rules for partner itineraries.
5. Southwest Airlines — Fare Types and Benefits — current fare-change and checked-baggage benefit rules.
6. ANA — International Route Information — current 2026 U.S.–Japan flight schedules.