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

Return flights

28 Aug - 04 Sep	Icelandair
30 Aug - 04 Sep	Icelandair
28 Aug - 02 Sep	Icelandair
22 Aug - 04 Sep	Icelandair
27 Aug - 01 Sep	Icelandair
26 Aug - 04 Sep	Icelandair
26 Aug - 02 Sep	Icelandair
25 Aug - 04 Sep	Icelandair
29 Aug - 04 Sep	Air Canada
29 Aug - 03 Sep	Air Canada
18 Aug - 26 Aug	United
18 Aug - 27 Aug	Icelandair
22 Aug - 30 Aug	Icelandair
18 Aug - 27 Aug	Aer Lingus	direct
19 Aug - 26 Aug	Delta
20 Aug - 27 Aug	Icelandair
20 Aug - 26 Aug	Icelandair
21 Aug - 26 Aug	Frontier Airlines
23 Aug - 31 Aug	SWISS
19 Aug - 27 Aug	Delta

Also check the deals for one-way flights from Seattle to Dublin in August.

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 August from 517€

Return flights