PetFlightCheck

Southwest Airlines Pet Policy (2026): Fees, Carrier Size & Rules

Yes. Southwest allows dogs and cats in the cabin on domestic flights only for $35 to $125 each way, per carrier, depending on the route. The carrier must fit under the seat in front of you, up to 18 × 10.5 × 10 in. Pets can't fly in cargo or as checked baggage.

Last verified against Southwest's official pages

PetFlightCheck is independent and not affiliated with Southwest Airlines. This page summarizes Southwest's official pet policy pages as of October 24, 2026; confirm the rules with Southwest before you book. Report an error

How to add your dog to a booking

  1. Reserve your pet's spot in advance by calling Southwest. Space is limited.
  2. On the day of travel, pay the Pet Fare at the airport ticket counter with an accepted credit card.
  3. At security, hold your pet and walk through the screening device while the carrier is X-rayed.
  4. Keep your pet fully inside the carrier in the gate area, during boarding, and for the whole flight, with the carrier under the seat in front of you.

Sources: Pet Policy, What can I expect at the airport when traveling with a pet?, What type of pet carrier can I bring?

Pet fee

$125

U.S. Mainland

each way, per carrier

$35

Between Hawaiian Islands

each way, per carrier

  • Paid at the airport ticket counter with an accepted credit card.
  • Refundable if you cancel your reservation.
  • Southwest says Pet Fare pricing is subject to change at any time.

Source: Optional Travel Charges

Carrier size and weight

Southwest doesn't publish a weight limit for pets in the cabin. What matters is the carrier: your pet has to fit inside it, and it has to fit under the seat in front of you.

Other pet carriers (maximum)

18 × 10.5 × 10 in

≈ 46 × 27 × 25 cm (L × W × H)

Southwest Airlines Pet Carrier

15 × 10 × 10 in

≈ 38 × 25 × 25 cm (L × W × H)

  • Soft-sided carrier recommended; under-seat space varies by seat type and is more limited in aisle seats.
  • Personal item or carry-on (board with the pet carrier plus one personal item or one regular carry-on bag).
  • Pets must be at least 8 weeks old.
  • 1 carrier per passenger, with up to 2 pets of the same species inside.

Where you can sit

  • Not in an exit row
  • Not in the first row (bulkhead)
  • Pets may never occupy a passenger seat

Sources: Pet Policy, What type of pet carrier can I bring?, What can I expect onboard when traveling with a pet?

Routes, breeds and other restrictions

Where pets can't fly

  • Flights to or from Hawaii (pets are accepted on flights between the Hawaiian Islands)
  • International flights, or any itinerary that includes an international flight

Breeds

No breed ban for short-nosed (brachycephalic) dogs. Not banned, but Southwest warns that animals with brachycephalic airways are more susceptible to complications during flight.

Also good to know

  • Unaccompanied Minors cannot travel with a pet.
  • Specific requirements may apply for travel to Puerto Rico.
  • A pet showing disruptive behavior (e.g. scratching, excessive whining or barking, growling, biting, lunging, urinating or defecating in the cabin or gate area) may be denied boarding.

Sources: What destination-specific information applies to pets?, Pet Policy, What else should I know about Southwest’s pet policy?

Cargo and checked pets

Southwest doesn't carry pets in the cargo hold, so a dog that doesn't fit in an under-seat carrier can't fly with Southwest.

Compare every airline's hold rules in our guide to airlines that fly dogs in the hold.

Source: Pet Policy

Service dogs and emotional support animals

  • Only trained service dogs are accepted as service animals.
  • Emotional support animals fly as regular pets, under the pet rules and fee on this page.
  • Required paperwork: U.S. Department of Transportation Service Animal Air Transportation form.

Source: I am traveling with a trained service dog

Other details

  • Pets do not earn Rapid Rewards points.
  • Southwest sells its own branded pet carrier at the ticket counter ($58 per carrier on the Optional Travel Charges page).

Before you fly

Southwest can change its pet policy at any time. We last checked these official pages on October 24, 2026. Confirm the rules with Southwest before you book and again before you travel.

Planning a trip? Our trip checker checks your dog against Southwest's cabin rules and, for trips abroad, gives you a dated checklist of what your dog needs.

Entry rules for your dog: Canada, Costa Rica, France, Germany, Hawaii, Italy, Japan, Mexico, Spain and United Kingdom (Great Britain).

Compare other airlines