In-cabin pet carriers that fit Southwest Airlines
The carriers from our list that clear Southwest Airlines's official 18.5 × 13.5 × 8.5 in under-seat limit — sorted best-fit first, with the ones that squeeze in when collapsed flagged.
📏 Height limit is only 8.5" — the same short ceiling as JetBlue. Standard 11"-tall carriers will not fit; choose a shorter or collapsible carrier.
| Carrier | Size | Fit | Buy |
|---|---|---|---|
| Sherpa Original Deluxe (Small) 15 × 10 × 8.5 in is within 18.5 × 13.5 × 8.5 in. · collapsible/flex | 15 × 10 × 8.5 in | Fits | See on Amazon → |
| Mr. Peanut's Gold Series Mini (Low-Profile) 9.8" tall vs a 8.5" limit, but the flexible-height top compresses down. Verify it squeezes under your actual seat. · collapsible/flex | 16 × 10.5 × 9.8 in | Flexes — check height | See on Amazon → |
| Sherpa Original Deluxe (Medium) 10.5" tall vs a 8.5" limit, but the flexible-height top compresses down. Verify it squeezes under your actual seat. · collapsible/flex | 17 × 11 × 10.5 in | Flexes — check height | See on Amazon → |
| Mr. Peanut's Gold Series Standard (Expandable) 11.5" tall vs a 8.5" limit, but the flexible-height top compresses down. Verify it squeezes under your actual seat. · collapsible/flex | 18.5 × 11.75 × 11.5 in | Flexes — check height | See on Amazon → |
| SturdiBag Pro (Large, Flexible Height) 11.5" tall vs a 8.5" limit, but the flexible-height top compresses down. Verify it squeezes under your actual seat. · collapsible/flex | 18 × 11.5 × 11.5 in | Flexes — check height | See on Amazon → |
Affiliate link — we may earn a small commission at no extra cost to you. It never changes our specs or which carriers we list.
Every fit is against the published maximum; real under-seat space varies by aircraft (why). Full rules & fees: Southwest Airlines pet policy →
Other airlines: Delta · JetBlue · American · United · Alaska · Frontier