$123 Cheap Frontier Airlines flights Seattle (SEA) to Knoxville (TYS)

Set the "Price (lowest to highest)" filter on Expedia to search for cheap Frontier Airlines round-trip flights from $235 from SEA to TYS. Affordable one-way options from $123 are also available.**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 Frontier 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 affect how much you pay. Sunday is typically the most affordable, 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 SEA to TYS with Frontier Airlines, sort your results by "Early Morning" and "Morning." Booking an early flight generally means you're less 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 chance to rack up points through Frontier Miles are the start of the reasons to depart from SEA to TYS with Frontier Airlines. Plus, when you sign up to our One Key™ program, you can receive OneKeyCash™* alongside any airline loyalty program earnings. It's yours to spend on future bookings.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.