Cheapest return flights from Seattle to Sydney in December from 916€

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

Return flights

14 Dec - 21 Dec Air Canada
25 Dec - 05 Jan Air Canada
11 Dec - 02 Jan Air Canada
21 Dec - 30 Dec Air Canada
18 Dec - 02 Jan STARLUX Airlines
17 Dec - 03 Jan Air Canada
18 Dec - 03 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.

Book a cheap hotel in Sydney

Cheap car rent in Sydney

Feel free to contact us with any feedback or request another flight research.