$109 Cheap United flights Washington (IAD) to Chicago (ORD)

Landing cheap one-way United Airlines flights from IAD to ORD from $109 on Expedia is simple — just filter by "Price (lowest to highest)." Alternatively, check out our budget-friendly round-trip fares from $217 for your next break.**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.

Begin your search one to three months before your departure to score cheap fares on United Airlines flights from Washington Dulles Intl. Airport (IAD) to O'Hare Intl. Airport (ORD). You can save 25% by booking your domestic flight 34 to 86 days in advance compared to last-minute reservations made 6 to 12 days out. You could also reduce costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Nail your timing, and you can enjoy significant savings on domestic journeys.*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.

The earliest flight from IAD to ORD with United Airlines departs at 8:25AM UTC-5. You'll touch down at 9:44AM UTC-6. The final United Airlines flight of the day takes off at 10:16PM UTC-5 and arrives at 11:22PM UTC-6. With approximately 20% fewer cancellations for morning departures, heading out early is often the best way to go.**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 opportunity to collect points through United Mileage Plus are the start of the reasons to leave from IAD to ORD with United Airlines. Plus, when you join our One Key™ program, you can earn OneKeyCash™* in addition to 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.