$100 Cheap United flights Chicago (ORD) to Portland (PWM)

Finding cheap one-way United Airlines flights from ORD to PWM from $100 on Expedia is simple — just filter by "Price (lowest to highest)." Or check out our affordable round-trip fares from $208 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.

Start searching one to three months ahead of your travel date to score cheap fares on United Airlines flights from O'Hare Intl. Airport (ORD) to Portland Intl. Jetport Airport (PWM). You can save 25% by booking your domestic flight 34 to 86 days in advance versus last-minute reservations made 6 to 12 days out. You could also cut costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Get the timing right, and you can enjoy significant savings on domestic trips.*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 United Airlines flight from ORD to PWM departs at 11:10AM UTC-6, touching down at 2:42PM UTC-5. If you'd like to jet off later, the last United Airlines flight leaves ORD at 11:10AM UTC-6 and touches down at PWM at 2:42PM UTC-5. Flying earlier is often a smart option as morning and mid-morning flights are least 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.

A rewarding loyalty program and the opportunity to collect points through United Mileage Plus are the start of the reasons to depart from ORD to PWM with United Airlines. Plus, when you join our One Key™ program, you can receive OneKeyCash™* on top of United Airlines's 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.