$120 Cheap United flights Billings (BIL) to Chicago (ORD)

Make use of the "Price (lowest to highest)" filter on Expedia to search for cheap United Airlines return flights from $201 from BIL to ORD. Affordable one-way tickets from $120 are also available.**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.

Search for cheap United Airlines flights from Logan Intl. Airport (BIL) to O'Hare Intl. Airport (ORD) one to three months ahead of your departure day. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. Regardless of fare class and journey, the best day to book a domestic flight is usually Sunday and the most expensive day tends to be Monday. Passengers who book on a Sunday can save 6% on average compared to those who book their travel on a Monday.**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.

Find United Airlines's earliest flights from BIL to ORD by checking our "Morning" and "Early Morning" filters. Not only will you arrive at your destination sooner, early departures also have a 20% less chance of being canceled.**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.

Fly from BIL to ORD with United Airlines and 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 could 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.