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

Return flights

12 Dec - 14 Jan	Lufthansa
10 Dec - 17 Dec	Lufthansa
09 Dec - 16 Dec	Lufthansa
12 Dec - 26 Dec	Lufthansa
07 Dec - 22 Dec	KLM
10 Dec - 17 Dec	Aer Lingus	direct
11 Dec - 24 Dec	Lufthansa
11 Dec - 18 Dec	Brussels Airlines
08 Dec - 15 Dec	Aer Lingus	direct
08 Dec - 14 Dec	Lufthansa
12 Dec - 26 Dec	Aer Lingus	direct
29 Dec - 06 Jan	Icelandair
22 Dec - 13 Jan	United
11 Dec - 05 Jan	Air France
28 Dec - 04 Jan	Icelandair
14 Dec - 04 Jan	Frontier Airlines
21 Dec - 04 Jan	Frontier Airlines
30 Dec - 06 Jan	Aer Lingus
27 Dec - 03 Jan	Icelandair
22 Dec - 02 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.

Book a cheap hotel in Dublin

Cheap car rent in Dublin

Cheapest return flights from Seattle to Dublin in December from 556€

Return flights