$583 Cheap United flights Washington (IAD) to Lisbon (LIS)

Apply the “Price (lowest to highest)” filter on Expedia to look for cheap United Airlines return flights from $829 from IAD to LIS. Affordable one-way tickets from $583 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.

United Airlines flights to Lisbon District are usually cheaper in the low-season months of January and February. Whether you’re in search of a return or one-way ticket, you could score a better deal then.

Snagging the best United Airlines deals from IAD to LIS often comes down to booking at the right time. You can save 17% on international flights when you book 18 to 29 days before takeoff instead of four to five months ahead. To top it off, you can pocket 17% on average by buying your fare on a Sunday rather than a Friday, which is usually the most expensive day to book.* It’s a good idea to start checking out flights about one month before you plan to travel.*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.

Use our “Nonstop” filter when browsing for direct United Airlines flights from IAD to LIS. It’s also a good way to compare other carriers offering the same nonstop trip.

Filter your results by “Morning” and “Early Morning” to see the earliest departures from IAD to LIS. Leaving early means you’re 20% 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.

Humberto Delgado Airport (LIS) is the main Lisbon District hub for United Airlines flights from Washington Dulles Intl. Airport (IAD).

Fly from IAD to LIS with United Airlines and you’ll enjoy a host of benefits including a rewarding loyalty program. When you book through Expedia as a United Mileage Plus and One Key™ member, you can also earn OneKeyCash™* to spend on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

Changes are typically free within 24 hours of booking, but your airline may charge a fee after that. For further information about modifying your flights, check out your “Trips,” select your flight and click on “Manage Booking.” If you’d like the freedom to adjust your plans without additional charges, check the “Changes included” or “No cancel fee” filter when organizing your next escape.