AirHint found the following cheapest one-way flights from Seattle (SEA) to San Jose (SJO) in December 2025 (see full year).
One-Way flights
| 05 Dec | Delta | ||
| 14 Dec | Frontier Airlines | ||
| 15 Dec | Frontier Airlines | ||
| 16 Dec | Hawaiian Airlines | ||
| 19 Dec | Frontier Airlines | ||
| 23 Dec | United | ||
| 20 Dec | Frontier Airlines |
Also check the deals for return flights from Seattle to San Jose in December.
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The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.
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