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

Return flights

03 Dec - 10 Dec	Aer Lingus	direct
08 Dec - 14 Dec	Icelandair
07 Dec - 14 Dec	Icelandair
01 Dec - 08 Dec	Lufthansa
01 Dec - 08 Dec	Aer Lingus	direct
10 Dec - 17 Dec	Aer Lingus	direct
03 Dec - 12 Dec	Aer Lingus	direct
05 Dec - 12 Dec	Aer Lingus	direct
15 Dec - 22 Dec	Aer Lingus	direct
09 Dec - 16 Dec	Icelandair
26 Dec - 17 Jan	Air Canada
23 Dec - 13 Jan	Iberia
24 Dec - 08 Jan	Delta
23 Dec - 08 Jan	United
23 Dec - 12 Jan	Iberia
23 Dec - 11 Jan	United
22 Dec - 09 Jan	Turkish Airlines
23 Dec - 09 Jan	KLM
28 Dec - 04 Jan	Lufthansa
14 Dec - 04 Jan	Hawaiian Airlines

Also check the deals for one-way flights from Seattle to Dublin 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 Seattle to Dublin in December from $417

Return flights