$100 Cheap American Airlines flights Ontario (ONT) to Seattle (SEA)

Make use of the "Price (lowest to highest)" filter on Expedia to search for cheap American Airlines round-trip flights from $159 from ONT to SEA. Affordable one-way options from $100 are also on offer.**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.

Begin your search one to three months ahead of your travel date to get cheaper fares on American Airlines flights from Los Angeles - Ontario Intl. Airport (ONT) to Seattle - Tacoma Intl. Airport (SEA). 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 the timing right, and you can enjoy significant savings on domestic journeys.*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 American Airlines's earliest flights from ONT to SEA by using the "Early Morning" and "Morning" filters. Not only will you arrive at your destination sooner, early departures also have a 20% less chance of being canceled.**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.