$185 Cheap Delta flights Tri-Cities (TRI) to Seattle (SEA)

Grab affordable round-trip Delta Air Lines flights from $399 from TRI to SEA by organizing your results from "Price (lowest to highest)" on Expedia. Or look for options from $185 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.

Look for affordable Delta Air Lines flights from Tri-Cities Regional Airport (TRI) to Seattle - Tacoma Intl. Airport (SEA) one to three months before your departure. 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 type and journey, the best day of the week to book a domestic flight is generally 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.

Filter your results by "Early Morning" and "Morning" to browse the earliest departures from TRI to SEA. Leaving early means flight 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.

Offering an excellent in-flight experience and a rewarding loyalty program, Delta Air Lines is a popular option for many travelers flying from TRI to SEA. What's more, if you're a Delta SkyMiles and One Key™ member booking through Expedia, you could earn OneKeyCash™* on eligible flights on top of your airline miles, which can be spent on future getaways.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.