$143 Cheap Frontier Airlines flights Kansas City (MCI) to Seattle (SEA)

Apply the "Price (lowest to highest)" filter on Expedia to find cheap Frontier Airlines return flights from $286 from MCI to SEA. Affordable one-way tickets from $143 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 Kansas City Intl. Airport (MCI) to Seattle - Tacoma Intl. Airport (SEA), start searching one to three months before your planned departure. Securing 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 what you pay. Sunday is generally the most affordable, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your journey 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 MCI to SEA with Frontier Airlines, filter your search by "Early Morning" and "Morning." Choosing an early flight usually means cancellations are less likely.**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, Frontier Airlines is a favorite of many passengers heading from MCI to SEA. Plus, if you're a Frontier Miles 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.