$149 Cheap American Airlines flights Seattle (SEA) to Philadelphia (PHL)

Scoring cheap one-way American Airlines flights from SEA to PHL from $149 on Expedia is a breeze — just filter by "Price (lowest to highest)." Or check out our budget-friendly return fares from $282 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.

Start searching one to three months ahead of your departure date to get cheap fares on American Airlines flights from Seattle - Tacoma Intl. Airport (SEA) to Philadelphia Intl. Airport (PHL). You can save 25% by booking your domestic flight 34 to 86 days in advance versus last-minute reservations made 6 to 12 days out. You could also reduce costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Get your timing spot on, and you can enjoy significant savings on domestic trips.*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.

Sort your results by "Early Morning" and "Morning" to browse the earliest flights from SEA to PHL. Setting off 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.