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£93 Cheap Flights from Seattle (SEA) to Ontario Intl. Airport (ONT)

View £93 flight on Wed, 9 Sept 2026Opens in a new window

Popular airlines from Seattle-Tacoma International Airport (SEA) to Ontario Intl. Airport (ONT)

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Cheap Flights from Seattle (SEA) to Ontario Intl. Airport (ONT)

Prices were available within the past 7 days and start at £93 for one-way flights and £171 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Alaska Airlines
Wed, 9 Sept - Sat, 12 Sept
SEA
Seattle
ONT
Ontario
£171 Return, found 3 days ago
£171
Return
found 3 days ago
Select Alaska Airlines flight, departing Wed, 9 Sept from Seattle to Ontario, returning Sat, 12 Sept, priced at £171 found 3 days ago
Alaska Airlines
Wed, 9 Sept - Sat, 12 Sept
SEA
Seattle
ONT
Ontario
£178 Return, found 3 days ago
£178
Return
found 3 days ago
Select Alaska Airlines flight, departing Wed, 9 Sept from Seattle to Ontario, returning Sat, 12 Sept, priced at £178 found 3 days ago
Alaska Airlines
Sat, 22 Aug - Sun, 23 Aug
SEA
Seattle
ONT
Ontario
£186 Return, found 3 days ago
£186
Return
found 3 days ago
Select Alaska Airlines flight, departing Sat, 22 Aug from Seattle to Ontario, returning Sun, 23 Aug, priced at £186 found 3 days ago
Alaska Airlines
Mon, 14 Sept - Mon, 21 Sept
SEA
Seattle
ONT
Ontario
£201 Return, found 1 day ago
£201
Return
found 1 day ago
Select Alaska Airlines flight, departing Mon, 14 Sept from Seattle to Ontario, returning Mon, 21 Sept, priced at £201 found 1 day ago
Alaska Airlines
Wed, 9 Sept - Sat, 12 Sept
SEA
Seattle
ONT
Ontario
£216 Return, found 3 days ago
£216
Return
found 3 days ago
Select Alaska Airlines flight, departing Wed, 9 Sept from Seattle to Ontario, returning Sat, 12 Sept, priced at £216 found 3 days ago
Alaska Airlines
Wed, 18 Nov - Wed, 25 Nov
SEA
Seattle
ONT
Ontario
£219 Return, found 6 days ago
£219
Return
found 6 days ago
Select Alaska Airlines flight, departing Wed, 18 Nov from Seattle to Ontario, returning Wed, 25 Nov, priced at £219 found 6 days ago
Delta
Sun, 9 Aug - Sun, 16 Aug
SEA
Seattle
ONT
Ontario
£371 Return, found 9 hours ago
£371
Return
found 9 hours ago
Select Delta flight, departing Sun, 9 Aug from Seattle to Ontario, returning Sun, 16 Aug, priced at £371 found 9 hours ago
United
Wed, 5 Aug - Sat, 15 Aug
SEA
Seattle
ONT
Ontario
£382 Return, found 9 hours ago
£382
Return
found 9 hours ago
Select United flight, departing Wed, 5 Aug from Seattle to Ontario, returning Sat, 15 Aug, priced at £382 found 9 hours ago
American Airlines
Fri, 14 Aug - Sat, 15 Aug
SEA
Seattle
ONT
Ontario
£416 Return, found 9 hours ago
£416
Return
found 9 hours ago
Select American Airlines flight, departing Fri, 14 Aug from Seattle to Ontario, returning Sat, 15 Aug, priced at £416 found 9 hours ago
Southwest Airlines
Fri, 14 Aug - Sat, 15 Aug
SEA
Seattle
ONT
Ontario
£446 Return, found 9 hours ago
£446
Return
found 9 hours ago
Select Southwest Airlines flight, departing Fri, 14 Aug from Seattle to Ontario, returning Sat, 15 Aug, priced at £446 found 9 hours ago

Alternative airports near Ontario

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to John Wayne SNA. Cheapest option available. Average driving time to city centre is 42 minutes. Flights from £163
SNA
John Wayne
Cheapest
Average driving time to city centre42 min
Flights from £163

Frequently asked questions

How much does a flight from Seattle, WA (SEA) to Ontario Intl. Airport (ONT) cost?
You can find one-way and return flights from Seattle, WA (SEA) to Ontario Intl. Airport (ONT) with Expedia. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see our cheapest fares first, and use the Price Tracking tool to receive alerts when SEA to ONT ticket fares go up or down.
What is the cheapest month to fly from Seattle, WA (SEA) to Ontario Intl. Airport (ONT)?
The cheapest months to fly from Seattle, WA (SEA) to Ontario Intl. Airport (ONT) are typically during off-peak season when demand is low. Traveling in off-peak or shoulder months is usually a good way to secure cheap tickets, just remember to avoid flying during holidays if you are able to. Use the calendar view in your search to see which months have low fares on this route.
Which airlines fly direct from Seattle, WA (SEA) to Ontario Intl. Airport (ONT)?
Enter SEA to ONT and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
How do I find cheap flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
To find a cheap flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best time to fly from Seattle, WA (SEA) to Ontario Intl. Airport (ONT)?
The best time to fly is usually mid-week (Tuesday or Wednesday) and during early morning hours as flights tend to be cheaper, less crowded, and generally more on-time. Avoid major holidays and peak vacation seasons for smoother travel. Combining off-peak days and hours often gives the best combination of cost, comfort, and convenience.
How many flights per day from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
You'll find around 5 nonstop flights per day from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT). For even more choices, look at flights that include layovers, as there are approximately 70 connecting flights per day. Some common connection points include Denver Intl. (DEN), Portland Intl. (PDX), and Sky Harbor Intl. (PHX).
What is the earliest flight from Seattle, WA (SEA) to Ontario Intl. Airport (ONT)?
Sort flights by "Departure (earliest)" on Expedia to find the earliest flight from Seattle, WA (SEA) to Ontario Intl. Airport (ONT). To compare more early flights, use the "Early Morning" and "Morning" filters in your search.
What day of the week has the most flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
You'll find the most flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) on a Friday, with around 63 flights available. This gives you a good selection of options for your travel plans. Major airlines on this route include Alaska Airlines, Southwest Airlines, and United. Flight options are notably more plentiful on Fridays compared to other days of the week, offering you more flexibility.
What are the most popular departure times for flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
The most popular departure times for flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) are in the morning, from 6am to 9am. Many major carriers, including Alaska Airlines, Southwest Airlines and Delta, offer flights during this window. Many travellers prefer this because it allows for an early start to their journey, giving them more time at their destination.
How long does it take to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
Flying nonstop from SEA to ONT takes around 2 hours 50 minutes, with the route covering approximately 1,540 kilometers. Flights with a layover typically take 2 hours 10 minutes longer than direct options. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
Yes, you can fly business class or first class between Seattle - Tacoma Intl. (SEA) and Ontario Intl. Airport (ONT).Airlines that offer business class service on this route include:
  • Frontier Airlines
  • Alaska Airlines
  • Delta
First class cabins are available on:
  • Alaska Airlines
  • Delta
  • Hawaiian Airlines
  • United
  • American Airlines
How do I earn miles on a Seattle, WA (SEA) to Ontario Intl. Airport (ONT) flight with Expedia?
It's easy to earn miles on a Seattle, WA (SEA) to Ontario Intl. Airport (ONT) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
Is it cheaper to buy a plane ticket from Seattle, WA (SEA) to Ontario Intl. Airport (ONT) at the last minute?
Typically, booking a last minute flight from Seattle, WA (SEA) to Ontario Intl. Airport (ONT) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Seattle, WA (SEA) to Ontario Intl. Airport (ONT) flight and hotel package?
Securing a Seattle, WA (SEA) to Ontario Intl. Airport (ONT) flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
If you booked your Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Seattle - Tacoma Intl.
Destination airport
Ontario Intl. Airport
Airlines serving
Alaska Airlines
Return price
£170
Distance
1530 km
Average flight time
2 hours 53 mins

Book with confidence

Compare flights from Seattle to Ontario Intl. Airport easily and book with confidence

For travelling on business or for pleasure, Expedia makes it easy to book your flights from Seattle to Ontario Intl. Airport. Operating between them flights per day, 20 airlines cover the route. And fly direct, getting you to Ontario Intl. Airport in just hours. If you have a preferred carrier, use our advanced search tool to find the right flight from Seattle - Tacoma Intl. to Ontario Intl. Airport.  

To make things even better, in the advanced search, you can also choose to fly economy, premium economy, business or first class, select your maximum number of stops, and pick your preferred departure and arrival time. You can also opt for refundable and direct flights. 

Grab a great deal on your flight from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT)

The easiest way to view the best deals on flights from Seattle to Ontario Intl. Airport today is to enter your travel dates and hit search. From here, you can sort your results by price to see the cheapest flights first. Right now, return flights from Seattle - Tacoma Intl. to Ontario Intl. Airport start at just £171 and range up to £446.  

To find an even better deal, try  

  • being flexible on your dates – midweek flights can be cheaper
  • looking for other airports near Seattle and Ontario Intl. Airport
  • booking your flight during September, the cheapest month on this route
  • varying your flight times – early morning and late at night are sometimes cheaper 

Why you should book your Seattle to Ontario Intl. Airport flight with Expedia!

We cater for all flight types, cabin classes and airlines. So whether you’re booking flights from Seattle - Tacoma Intl. to Ontario Intl. Airport for a budget break or a business trip with a bit of pleasure thrown in, we make it easy to secure the seat that’s right for you.  

Thanks to our supersized inventory that offers great choice all in one place, you know you’ll get a great deal with Expedia. Especially if you bundle your flight together with your hotel, you will unlock amazing savings. For added peace of mind, you can choose flexible bookings or filter to find refundable options, so you won’t pay a fee to change your flight.  

Compare flights from Seattle to Ontario Intl. Airport easily and book with confidence

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