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

Return flights

04 Dec - 13 Dec	Icelandair
04 Dec - 11 Dec	Icelandair
02 Dec - 09 Dec	Icelandair
02 Dec - 15 Dec	Icelandair
03 Dec - 07 Dec	TAP
09 Dec - 19 Dec	Aer Lingus	direct
12 Dec - 18 Dec	Icelandair
29 Dec - 24 Jan	Icelandair
03 Dec - 10 Dec	Aer Lingus	direct
09 Dec - 16 Dec	Aer Lingus	direct
02 Dec - 09 Dec	Aer Lingus	direct
27 Dec - 13 Jan	Lufthansa
27 Dec - 13 Jan	Aer Lingus	direct
29 Dec - 24 Jan	Aer Lingus	direct
27 Dec - 17 Jan	Air Canada
24 Dec - 17 Jan	British Airways
16 Dec - 13 Jan	Icelandair
16 Dec - 10 Jan	Icelandair
26 Dec - 17 Jan	Aer Lingus	direct
27 Dec - 17 Jan	Aer Lingus	direct

Also check the deals for one-way flights from Washington 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 Washington to Dublin in December from $400

Return flights