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

View AU$210 flight on Fri, 29 Jan 2027Opens 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 for one-way flights and round trip tickets for the period specified. Prices and availability are subject to change. Additional terms apply.

Alaska Airlines
Fri, 18 Sept - Fri, 25 Sept
SEA
Seattle
ONT
Ontario
AU$394 Return, found 2 days ago
AU$394
Return
found 2 days ago
Select Alaska Airlines flight, departing Fri, 18 Sept from Seattle to Ontario, returning Fri, 25 Sept, priced at AU$394 found 2 days ago
Delta
Fri, 18 Sept - Fri, 25 Sept
SEA
Seattle
ONT
Ontario
AU$394 Return, found 2 days ago
AU$394
Return
found 2 days ago
Select Delta flight, departing Fri, 18 Sept from Seattle to Ontario, returning Fri, 25 Sept, priced at AU$394 found 2 days ago
Alaska Airlines
Fri, 18 Sept - Fri, 25 Sept
SEA
Seattle
ONT
Ontario
AU$408 Return, found 2 days ago
AU$408
Return
found 2 days ago
Select Alaska Airlines flight, departing Fri, 18 Sept from Seattle to Ontario, returning Fri, 25 Sept, priced at AU$408 found 2 days ago
Alaska Airlines
Fri, 18 Sept - Fri, 25 Sept
SEA
Seattle
ONT
Ontario
AU$423 Return, found 2 days ago
AU$423
Return
found 2 days ago
Select Alaska Airlines flight, departing Fri, 18 Sept from Seattle to Ontario, returning Fri, 25 Sept, priced at AU$423 found 2 days ago
Delta
Fri, 18 Sept - Fri, 25 Sept
SEA
Seattle
ONT
Ontario
AU$437 Return, found 2 days ago
AU$437
Return
found 2 days ago
Select Delta flight, departing Fri, 18 Sept from Seattle to Ontario, returning Fri, 25 Sept, priced at AU$437 found 2 days ago
Alaska Airlines
Mon, 14 Sept - Fri, 18 Sept
SEA
Seattle
ONT
Ontario
AU$449 Return, found 2 days ago
AU$449
Return
found 2 days ago
Select Alaska Airlines flight, departing Mon, 14 Sept from Seattle to Ontario, returning Fri, 18 Sept, priced at AU$449 found 2 days ago
Alaska Airlines
Fri, 18 Sept - Fri, 25 Sept
SEA
Seattle
ONT
Ontario
AU$463 Return, found 2 days ago
AU$463
Return
found 2 days ago
Select Alaska Airlines flight, departing Fri, 18 Sept from Seattle to Ontario, returning Fri, 25 Sept, priced at AU$463 found 2 days ago
Alaska Airlines
Mon, 28 Sept - Mon, 5 Oct
SEA
Seattle
ONT
Ontario
AU$465 Return, found 1 hour ago
AU$465
Return
found 1 hour ago
Select Alaska Airlines flight, departing Mon, 28 Sept from Seattle to Ontario, returning Mon, 5 Oct, priced at AU$465 found 1 hour ago
United
Wed, 9 Sept - Mon, 14 Sept
SEA
Seattle
ONT
Ontario
AU$513 Return, found 4 hours ago
AU$513
Return
found 4 hours ago
Select United flight, departing Wed, 9 Sept from Seattle to Ontario, returning Mon, 14 Sept, priced at AU$513 found 4 hours ago
American Airlines
Mon, 28 Sept - Mon, 5 Oct
SEA
Seattle
ONT
Ontario
AU$549 Return, found 1 hour ago
AU$549
Return
found 1 hour ago
Select American Airlines flight, departing Mon, 28 Sept from Seattle to Ontario, returning Mon, 5 Oct, priced at AU$549 found 1 hour ago

Find the cheapest month to fly from Seattle (SEA) to Ontario (ONT)

August is typically the cheapest month to fly

From AU$125 - AU$353 per traveller.

Frequently asked questions

How much does a flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT) cost?
You can find one-way and return flights from SEA to 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-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
January is typically the cheapest month to fly from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT), with average return fares around AU$373. January sees lower prices because it falls after the holiday travel rush, when demand drops and airlines compete for bookings. February and September are also good months to find deals on this route.
Which airlines fly direct from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
There are 2 airlines offering direct flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT). Here are the carriers:
  • Delta operates 31 direct flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) every week.
  • Frontier Airlines operates 7 direct flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) every week.
What is the cheapest airline that flies from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
Mineta San Jose Intl. (SJC), starting from around AU$124. Airport (ONT), with tickets starting from around AU$421 for flights that can be booked for departure within the next year. Southwest Airlines is one of the cheapest airlines offering nonstop return flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Southwest Airlines also offers one of the cheapest connecting return flights on this route, with a layover in Norman Y. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.
How do I find cheap flights from Seattle, WA (SEA) to Ontario Intl. Airport (ONT)?
To find a cheap flight from Seattle, WA (SEA) 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 airline to fly with from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
The best airline to fly with from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) will differ from traveler to traveler. If you like to fly early, Delta offers early morning flights. If price is the most important factor, Southwest Airlines typically offers the lowest fares. Southwest Airlines offers the most daily flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT), which is great if flexibility is what you value most. The best carrier for this journey could also be the one you have a loyalty membership with, as flying with that airline or another airline within the same alliance could help you collect points or enjoy lounge access.
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-Seattle - Tacoma Intl.) to Ontario Intl. Airport (ONT)?
The earliest flight from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) typically departs around 12:25 AM. This flight is operated by American Airlines. This is a seasonal service, active only in September. An early departure like this can be great if you want to maximize your time at your destination. To compare early flights on Expedia, select 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 Intl. Airport (ONT)?
A nonstop flight from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) typically takes around 2 hours 48 minutes. This route covers a distance of approximately 1540 kilometres. If you opt for a flight with one stop, your travel time will be longer, usually around 5 hours. Flights with two or more stops generally take about 11 hours 30 minutes. Keep in mind that actual flight times can vary due to factors like wind patterns and air traffic, so it's always a good idea to allow for some extra time when planning your journey.
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.
What airports do you fly into for Ontario Intl. Airport (ONT) from Seattle, WA (SEA)?
If you're planning to travel to Ontario from Seattle - Tacoma Intl. (SEA), you can fly directly into Los Angeles - Ontario Intl. (ONT). Some flights may connect through major hubs like Denver Intl. (DEN), Los Angeles Intl. (LAX), or Harry Reid International Airport (LAS) before reaching Ontario. Compare routes and airports on Expedia to find the best flight options for your travel plans.
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) to Ontario Intl. Airport (ONT)?
If you booked your Seattle, WA (SEA) 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, American Airlines, Delta, United
Roundtrip price
AU$393
Distance
1530 km
Average flight time
2 hours 55 mins

Book with confidence

Your quick guide to flights from Seattle to Ontario Intl. Airport

Pick up great flights from Seattle to Ontario Intl. Airport

With Expedia, you have your pick of flights a day with 20 airlines covering flights from Seattle to Ontario Intl. Airport. Whether you’re on a business trip, a family holiday or a luxury break, just enter your travel dates, hit search then check out your choice of flights. Select from return, one way or multi-city flights, and use the advance search tool if you want a direct or refundable flight. You can narrow your search to show you just your preferred cabin class and airline, too. It’s all easy. You can book direct flights from Seattle to Ontario Intl. Airport that take around hours.

Find cheap flights from Seattle to Ontario Intl. Airport

From the great flight deals with prices currently ranging from AU$394 to AU$549, you can choose to see the cheapest flights first. Generally, you can book the cheapest flights from Seattle to Ontario Intl. Airport around 4 to 6 weeks in advance. If your travel dates are flexible, try to avoid weekends and peak seasons – when you are more likely to grab the lowest prices. Even last minute, there are some impressive deals. The cheapest time to fly to Ontario Intl. Airport is normally in September.

Reasons to book your flight from Seattle to Ontario Intl. Airport with Expedia

Expedia makes it easy to find, book, and travel, with everything you need all in one place. When you enter your travel details, find fantastic deals just for you on flight tickets from Seattle to Ontario Intl. Airport across all the main airline carriers, so you can save time, dollars, and hassle finding the perfect flight. If you think your plans could change, choose refundable flights so any changes won’t cost you more. Book your flight to Ontario Intl. Airport right now and, if you join Expedia Rewards, you earn points this time and every time you travel with Expedia.

Your quick guide to flights from Seattle to Ontario Intl. Airport

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