Southwest Airlines in-cabin pet policy — and the carriers that fit
Southwest Airlines allows small pets in the cabin in a carrier up to 18.5 × 13.5 × 8.5 in, stowed under the seat in front of you. The in-cabin fee is $125 each way. 1 of the 15 carriers we track clears that published limit.
The only one that clears it — the Sherpa Original Deluxe (Small) — matches Southwest's published limit exactly, with no measurable slack, so measure your own carrier before you fly. Southwest's 8.5" height ceiling sits mid-pack among the 17 airlines we track (shared with JetBlue, WestJet): Delta, American, United and Alaska allow more, while Air Canada allows only 8".
Southwest Airlines pet rules
| Recommended max carrier (soft) | 18.5 × 13.5 × 8.5 in |
| Soft-sided required? | Soft recommended; hard allowed within its limit |
| In-cabin fee | $125 each way · compare all airlines → |
| Species allowed | cats, dogs |
| Pets | 1 carrier per passenger; 2 same-species pets may share one compliant carrier |
| Booking | Add at the airport or by calling; limited pets per flight |
Source: official Southwest Airlines pet policy · verified 2026-07-23
Carriers that fit Southwest Airlines
Matched to Southwest Airlines's published 18.5 × 13.5 × 8.5 in limit (height checked strictly; footprint may rotate). See the full Southwest Airlines carrier shortlist →
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| Carrier | Size | Fit | Buy |
|---|---|---|---|
| 15 × 10 × 8.5 in | Fits 0" spare | See on Amazon → | |
| 16 × 10.5 × 9.8 in | Flexes — check height | See on Amazon → | |
| 17 × 11 × 10.5 in | Flexes — check height | See on Amazon → | |
| 18.5 × 11.75 × 11.5 in | Flexes — check height | See on Amazon → | |
| 18 × 11.5 × 11.5 in | Flexes — check height | See on Amazon → | |
| 17 × 10 × 10 in | Too tall (10" > 8.5") | See on Amazon → | |
| 17 × 12 × 10.5 in | Too tall (10.5" > 8.5") | See on Amazon → | |
| 17 × 8.5 × 10.5 in | Too tall (10.5" > 8.5") | See on Amazon → | |
| 17 × 11 × 11 in | Too tall (11" > 8.5") | See on Amazon → | |
| 16 × 8 × 11 in | Too tall (11" > 8.5") | See on Amazon → | |
| 18 × 11 × 11 in | Too tall (11" > 8.5") | See on Amazon → | |
| 18 × 12 × 12 in | Too tall (12" > 8.5") | See on Amazon → | |
| 22 × 10.5 × 10.5 in | Too big | See on Amazon → | |
| 18.7 × 10.8 × 10.75 in | Too big | See on Amazon → | |
| 19 × 11.75 × 11.5 in | Too big | See on Amazon → |
How to confirm your actual under-seat space
Southwest Airlines's number is a fleet-wide recommendation, not a promise for your exact seat. Before you buy or fly:
- Check which aircraft operates your flight (in your booking or on a seat-map site).
- Avoid bulkhead and some window seats — they have less (or no) under-seat storage.
- Call Southwest Airlines to confirm under-seat dimensions for that aircraft, or
- Choose a collapsible / flexible-height carrier that adapts to a tighter space.
More airlines: Delta · JetBlue · American · United · Alaska · Frontier · all →
Common questions
What size pet carrier does Southwest Airlines allow in the cabin?
Southwest Airlines's recommended maximum in-cabin carrier is 18.5 × 13.5 × 8.5 in. It must fit fully under the seat in front of you. Source: the Southwest Airlines pet policy.
How much does Southwest Airlines charge for an in-cabin pet?
$125 each way. Always confirm the current fee on the official Southwest Airlines pet page before you fly.
Which pet carriers fit Southwest Airlines?
1 of the 15 carriers we track clears Southwest Airlines's published 18.5 × 13.5 × 8.5 in. The roomiest is the Sherpa Original Deluxe (Small), and even that one matches the limit exactly rather than clearing it, so measure before you fly. Full shortlist: /fits/southwest/.
Does Southwest Airlines require a soft-sided pet carrier?
Southwest Airlines recommends soft-sided but allows a hard-sided kennel within its published limit. Height is what rules carriers out: Southwest Airlines publishes 8.5", against 13" at the most generous airline we track.
How many pets can I bring in the cabin on Southwest Airlines?
1 carrier per passenger; 2 same-species pets may share one compliant carrier. Species accepted: cats, dogs. Add at the airport or by calling; limited pets per flight