$231 Cheap United flights Seattle (SEA) to Knoxville (TYS)

You can find cheap round-trip United Airlines flights from $309 from SEA to TYS by sorting your results from "Price (lowest to highest)" on Expedia. Or search for bargains from $231 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.

To find cheap United Airlines fares from Seattle - Tacoma Intl. Airport (SEA) to McGhee Tyson Airport (TYS), 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 impact what you pay. Sunday tends to be the most affordable, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your trip 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.

Find United Airlines's earliest flights from SEA to TYS by using the "Morning" and "Early Morning" filters. Not only will you get to where you're going 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.

Offering a rewarding loyalty program, United Airlines is a popular choice for many passengers flying from SEA to TYS. Plus, as a United Mileage Plus and One Key™ member booking through Expedia, you could earn OneKeyCash™* on eligible flights on top of your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.