$393 Cheap Flights from Seattle (BFI) to Ontario (ONT)

View $393 flight on Sun, Sep 14, 2025Opens in a new window

Popular airlines from Seattle, WA (BFI-Boeing Field) to Los Angeles - Ontario Intl. Airport (ONT)

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Cheap Flights from Seattle to Ontario (BFI-ONT)

Prices were available within the past 7 days and start at $393 for one-way flights and $785 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Air Excursions LLC
Sun, Sep 14 - Tue, Sep 30
BFI
Seattle
ONT
Ontario
$785 Roundtrip, found 5 days ago
$785
Roundtrip
found 5 days ago
Select Air Excursions LLC flight, departing Sun, Sep 14 from Seattle to Ontario, returning Tue, Sep 30, priced at $785 found 5 days ago
Air Excursions LLC
Sat, Aug 16 - Tue, Aug 19
BFI
Seattle
ONT
Ontario
$795 Roundtrip, found 2 days ago
$795
Roundtrip
found 2 days ago
Select Air Excursions LLC flight, departing Sat, Aug 16 from Seattle to Ontario, returning Tue, Aug 19, priced at $795 found 2 days ago
Air Excursions LLC
Sat, Aug 16 - Fri, Aug 22
BFI
Seattle
ONT
Ontario
$805 Roundtrip, found 2 days ago
$805
Roundtrip
found 2 days ago
Select Air Excursions LLC flight, departing Sat, Aug 16 from Seattle to Ontario, returning Fri, Aug 22, priced at $805 found 2 days ago
Air Excursions LLC
Thu, Aug 21 - Tue, Aug 26
BFI
Seattle
ONT
Ontario
$815 Roundtrip, found 3 days ago
$815
Roundtrip
found 3 days ago
Select Air Excursions LLC flight, departing Thu, Aug 21 from Seattle to Ontario, returning Tue, Aug 26, priced at $815 found 3 days ago
Air Excursions LLC
Tue, Aug 12 - Tue, Aug 19
BFI
Seattle
ONT
Ontario
$825 Roundtrip, found 2 days ago
$825
Roundtrip
found 2 days ago
Select Air Excursions LLC flight, departing Tue, Aug 12 from Seattle to Ontario, returning Tue, Aug 19, priced at $825 found 2 days ago
Air Excursions LLC
Tue, Aug 12 - Fri, Aug 22
BFI
Seattle
ONT
Ontario
$835 Roundtrip, found 2 days ago
$835
Roundtrip
found 2 days ago
Select Air Excursions LLC flight, departing Tue, Aug 12 from Seattle to Ontario, returning Fri, Aug 22, priced at $835 found 2 days ago
Air Excursions LLC
Fri, Sep 5 - Mon, Sep 8
BFI
Seattle
ONT
Ontario
$845 Roundtrip, found 4 days ago
$845
Roundtrip
found 4 days ago
Select Air Excursions LLC flight, departing Fri, Sep 5 from Seattle to Ontario, returning Mon, Sep 8, priced at $845 found 4 days ago
Air Excursions LLC
Tue, Aug 12 - Mon, Aug 25
BFI
Seattle
ONT
Ontario
$845 Roundtrip, found 5 days ago
$845
Roundtrip
found 5 days ago
Select Air Excursions LLC flight, departing Tue, Aug 12 from Seattle to Ontario, returning Mon, Aug 25, priced at $845 found 5 days ago
Air Excursions LLC
Tue, Aug 5 - Fri, Aug 22
BFI
Seattle
ONT
Ontario
$855 Roundtrip, found 5 days ago
$855
Roundtrip
found 5 days ago
Select Air Excursions LLC flight, departing Tue, Aug 5 from Seattle to Ontario, returning Fri, Aug 22, priced at $855 found 5 days ago
Air Excursions LLC
Sun, Aug 10 - Tue, Aug 19
BFI
Seattle
ONT
Ontario
$860 Roundtrip, found 2 days ago
$860
Roundtrip
found 2 days ago
Select Air Excursions LLC flight, departing Sun, Aug 10 from Seattle to Ontario, returning Tue, Aug 19, priced at $860 found 2 days ago
Flights from Seattle (BFI) to Ontario (ONT)
Origin airport
Boeing Field
Destination airport
Los Angeles - Ontario Intl.
Roundtrip price
$785
Distance
962 mi

Seattle to Ontario Flights

The cheapest times to fly from Seattle to Ontario

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Seattle to Ontario are during the month of September. You can find some of the cheapest flights from Seattle to Ontario with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Seattle to Ontario

Sunday is one of the best days to book for cheap flights from Seattle to Ontario: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Seattle to Ontario

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Seattle to Ontario in 2025. You can also book with separate airlines for your outbound and return journeys, from $393 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Seattle to Ontario flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Seattle to Ontario airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Boeing Field Airport (BFI) to Los Angeles - Ontario Intl. Airport (ONT) cost?
Discover the latest flight deals from BFI to ONT by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from BFI to ONT?
The cheapest flights from BFI to ONT are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from Boeing Field Airport (BFI) to Los Angeles - Ontario Intl. Airport (ONT)?
You can't fly nonstop to Los Angeles - Ontario Intl. Airport (ONT) from Seattle, WA (BFI-Boeing Field). However, you can easily reach Ontario without any layovers by leaving from Seattle - Tacoma Intl. Airport (SEA).
What is the cheapest airline that flies from BFI to ONT?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from BFI to ONT. Sort your results by "Price (lowest to highest)" to snap up a great deal.
How many flights per day from Boeing Field Airport (BFI) to Los Angeles - Ontario Intl. Airport (ONT)?
Nonstop flights from Boeing Field Airport (BFI) to Los Angeles - Ontario Intl. Airport (ONT) aren't available daily, so you'll need to take a flight with a layover. Explore your options with Expedia's filters. Enter your travel dates and select either "1 Stop" or "2+ Stops."
What day of the week has the most flights from BFI to ONT?
Typically you'll find the greatest selection of flight options on a Friday. Tuesdays are often the quietest.* However, this can vary depending on the time of year, airline and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Boeing Field Airport (BFI) to Los Angeles - Ontario Intl. Airport (ONT)?
Opt for a flight from Boeing Field Airport (BFI) to Los Angeles - Ontario Intl. Airport (ONT) that takes off before 3 PM to reduce the likelihood of delays and cancellations. Departures after this time have a 22% higher chance of being canceled, on average.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Boeing Field Airport (BFI) to Los Angeles - Ontario Intl. Airport (ONT) last-minute?
Holding off until right before your break to book your flight from BFI to ONT generally means paying more. While you might find some last-minute offers, there's no guarantee. Keep your travel plans flexible to maximize your chances of landing a bargain.
Is it cheaper to book a BFI to ONT flight and hotel package?
You'll typically save money by securing a BFI to ONT flight and hotel package compared to booking separately. In fact, you could save hundreds of dollars by bundling with Expedia. And it's easy to manage it all in one convenient place. After choosing your ideal flights and accommodations, consider adding extras like activities, tours and car rentals.
Can I cancel or change the date of my flight from Boeing Field Airport (BFI) to Los Angeles - Ontario Intl. Airport (ONT)?
In most cases, you can cancel or modify your BFI to ONT flight. However, additional charges may apply, especially if your booking was made more than 24 hours ago. Check your itinerary for the airline's rules and fees on flight changes, or if you want further information, visit our Customer Service portal.

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*Available to One Key members.