$129 Cheap American Airlines flights Washington (IAD) to Chicago (ORD)

Landing cheap one-way American Airlines flights from IAD to ORD from $129 on Expedia is easy — just filter by "Price (lowest to highest)." Alternatively, check out our budget-friendly return fares from $272 for your next getaway.**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.

For cheap American Airlines fares from Washington Dulles Intl. Airport (IAD) to O'Hare Intl. Airport (ORD), start searching one to three months before your intended departure. Reserving domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also impact the overall price. Sunday is typically the most affordable, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking on a Sunday.**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.

Sort your results by "Morning" and "Early Morning" to browse the earliest departures from IAD to ORD. 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.