AirHint found the following cheapest one-way flights from Seattle (SEA) to Sydney (SYD) in December 2025 (see full year).
One-Way flights
| 01 Dec | ANA | ||
| 09 Dec | Qantas | ||
| 30 Dec | United | ||
| 10 Dec | United | ||
| 24 Dec | Hawaiian Airlines | ||
| 26 Dec | Hawaiian Airlines | ||
| 23 Dec | Air Canada | ||
| 22 Dec | Air Canada | ||
| 13 Dec | Frontier Airlines | ||
| 12 Dec | Alaska Airlines |
Also check the deals for return flights from Seattle to Sydney 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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