AirHint found the following cheapest return flights from Washington (DCA) to Dublin (DUB) in September 2025 (see full year).

Return flights

02 Sep - 05 Sep	jetBlue
28 Sep - 05 Oct	jetBlue
29 Sep - 06 Oct	jetBlue
04 Sep - 12 Sep	jetBlue
10 Sep - 17 Sep	United
09 Sep - 16 Sep	United
05 Sep - 15 Sep	jetBlue
04 Sep - 11 Sep	United
02 Sep - 12 Sep	United
12 Sep - 19 Sep	United
22 Sep - 27 Sep	jetBlue
11 Sep - 18 Sep	United
30 Sep - 07 Oct	United
25 Sep - 06 Oct	Air Canada
16 Sep - 11 Oct	Air Canada
23 Sep - 07 Oct	Air Canada
23 Sep - 05 Oct	Scandinavian Airlines
26 Sep - 03 Oct	jetBlue
25 Sep - 18 Oct	jetBlue
25 Sep - 04 Oct	jetBlue

Also check the deals for one-way flights from Washington 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 return flights from Washington to Dublin in September from 430€

Return flights