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

Return flights

02 Dec - 09 Dec	Alaska Airlines
12 Dec - 31 Dec	Fiji Airways
26 Dec - 23 Jan	Fiji Airways
10 Dec - 14 Jan	Fiji Airways
08 Dec - 04 Jan	Air New Zealand
29 Dec - 25 Jan	Air Canada
30 Dec - 28 Jan	Air Canada
30 Dec - 19 Jan	Air Canada
07 Dec - 14 Dec	Fiji Airways
12 Dec - 13 Jan	Air New Zealand
10 Dec - 10 Jan	Alaska Airlines
07 Dec - 12 Jan	Hawaiian Airlines
31 Dec - 23 Jan	Delta
13 Dec - 23 Dec	Air Canada
11 Dec - 27 Dec	Air Canada
10 Dec - 27 Dec	Air Canada
13 Dec - 20 Dec	Air Canada
07 Dec - 14 Dec	United	direct
23 Dec - 30 Dec	Air Canada
12 Dec - 31 Dec	United	direct

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

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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Cheapest return flights from San Francisco to Sydney in December from 812€

Return flights