Cheap United flights Washington (IAD) to Dublin (DUB)

Use the "Price (lowest to highest)" filter on Expedia to search for cheap United Airlines return flights from $413 from IAD to DUB. Affordable one-way options are available as well.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Start your search for United Airlines flights from IAD to DUB about one month before you want to leave. The cheapest time to reserve an international flight is generally 18 to 29 days ahead of your departure date when you can save 17% versus booking four to five months in advance. Regardless of fare class or itinerary, the best day of the week to book international airfare is usually Sunday. Friday is often the most expensive. Passengers booking on a Sunday can save 17% on average compared to those who book on a Friday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

To find the earliest departures from IAD to DUB with United Airlines, filter your results by "Early Morning" and "Morning." Choosing an early flight usually means you're less likely to experience cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.

A rewarding loyalty program and the ability to collect points through United Mileage Plus are the start of the reasons to depart from IAD to DUB with United Airlines. Plus, when you sign up to our One Key™ program, you can earn OneKeyCash™* alongside any airline loyalty program earnings. It's yours to spend on future travel plans.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.