Cheapest return flights from Seattle to Sydney in December from 1711€

AirHint found the following cheapest return flights from Seattle (SEA) to Sydney (SYD) in December 2025 (see full year).

Return flights

26 Dec - 03 Jan Air Canada
22 Dec - 05 Jan Air Canada
19 Dec - 30 Dec Asiana Airlines
16 Dec - 04 Jan Air Canada
18 Dec - 04 Jan Air Canada
19 Dec - 04 Jan Air Canada
14 Dec - 09 Jan Delta

Also check the deals for one-way flights from Seattle to Sydney in December.

Skyscanner

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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