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

Return flights

30 Dec - 13 Jan	SWISS
29 Dec - 12 Jan	Air Canada
30 Dec - 12 Jan	SWISS
31 Dec - 20 Jan	Air Canada
13 Dec - 12 Jan	Lufthansa
16 Dec - 23 Dec	Lufthansa
13 Dec - 20 Dec	Lufthansa
14 Dec - 12 Jan	Lufthansa
16 Dec - 22 Dec	Lufthansa
27 Dec - 12 Jan	British Airways
15 Dec - 25 Dec	United
26 Dec - 13 Jan	TAP
14 Dec - 11 Jan	British Airways
27 Dec - 11 Jan	British Airways
24 Dec - 26 Dec	Lufthansa
25 Dec - 28 Dec	SWISS
16 Dec - 19 Dec	Lufthansa
26 Dec - 29 Dec	KLM
24 Dec - 28 Dec	Lufthansa
23 Dec - 25 Dec	Aer Lingus

Also check the deals for one-way flights from San Francisco to Barcelona 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 Barcelona in December from $463

Return flights