$105 Cheap United flights Colorado Springs (COS) to Phoenix (PHX)

Finding cheap one-way United Airlines flights from COS to PHX from $105 on Expedia is simple — just filter by "Price (lowest to highest)." Alternatively, check out our budget-friendly return fares from $189 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.

For cheap United Airlines fares from Colorado Springs Airport (COS) to Sky Harbor Intl. Airport (PHX), 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 influence what you pay. Sunday is usually the cheapest, 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.

To find the earliest departures from COS to PHX with United Airlines, filter your search by "Morning" and "Early Morning." Choosing an early flight usually means you'll experience 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.

With a rewarding loyalty program, United Airlines is a popular choice for many travelers heading from COS to PHX. Plus, if you're a United Mileage Plus and One Key™ member booking through Expedia, you could earn OneKeyCash™* on eligible flights along with your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.