$139 Cheap United flights Denver (DEN) to Knoxville (TYS)

Landing cheap one-way United Airlines flights from DEN to TYS from $139 on Expedia is easy — just filter by "Price (lowest to highest)." Alternatively, check out our affordable return fares from $214 for your next exciting getaway.**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 affordable United Airlines flights from Denver Intl. Airport (DEN) to McGhee Tyson Airport (TYS) 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 ideal day to book a domestic flight is usually Sunday and the most expensive day is typically 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.

Departing DEN at 9:59AM UTC-7, the earliest United Airlines flight to TYS lands at 2:59PM UTC-5. Traveling earlier in the day means you'll be less likely to experience cancellations.* After something later? The last United Airlines flight from DEN to TYS departs at 5:31PM UTC-7 and touches down at 10:29PM UTC-5.*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 collect points through United Mileage Plus are the start of the reasons to leave from DEN to TYS with United Airlines. Plus, by joining Expedia's free 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.