$109 Cheap United flights Seattle (SEA) to Colorado Springs (COS)

You'll discover affordable return United Airlines flights from $217 from SEA to COS by organizing your results from "Price (lowest to highest)" on Expedia. Or search for bargains from $109 for a one-way journey.**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 departure date to find cheap fares on United Airlines flights from Seattle - Tacoma Intl. Airport (SEA) to Colorado Springs Airport (COS). 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 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 your timing spot on, 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.

Browse United Airlines's earliest flights from SEA to COS by selecting the "Early Morning" and "Morning" filters. Not only will you get to your destination sooner, early departures also experience 20% fewer 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 ability to rack up points through United Mileage Plus are the start of the reasons to leave from SEA to COS with United Airlines. Plus, by joining Expedia's free One Key™ program, you can receive OneKeyCash™* alongside United Airlines's loyalty program earnings. It's yours to use wherever your next trip takes you.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.