AirHint found the following cheapest one-way flights from Seattle (SEA) to Dublin (DUB) in September 2025 (see full year).

One-Way flights

03 Sep	Icelandair
02 Sep	Icelandair
01 Sep	Icelandair
17 Sep	United
26 Sep	Air Canada
03 Sep	Aer Lingus	direct
01 Sep	Aer Lingus	direct
02 Sep	Aer Lingus	direct
17 Sep	Aer Lingus	direct
26 Sep	Aer Lingus	direct

Also check the deals for return flights from Seattle to Dublin in September.

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 one-way flights from Seattle to Dublin in September from $284

One-Way flights