$144 Cheap United flights Rapid City (RAP) to Chicago (ORD)

You can find affordable round-trip United Airlines flights from $209 from RAP to ORD by organizing your results from "Price (lowest to highest)" on Expedia. Or search for bargains from $144 for a one-way trip.**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.

To find cheap United Airlines fares from Rapid City Regional Airport (RAP) to O'Hare Intl. Airport (ORD), start searching one to three months before your planned 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 cost. Sunday is generally the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by choosing to book 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.

Filter your results by "Morning" and "Early Morning" to find the earliest departures from RAP to ORD. Heading off early means flight cancellations are less likely.**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.

Offering a rewarding loyalty program, United Airlines is a top choice for many passengers flying from RAP to ORD. Plus, as a United Mileage Plus and One Key™ member booking through Expedia, you can earn OneKeyCash™* on eligible flights on top of your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.