£95 Cheap Flights from Seattle (SEA) to Ontario Intl. Airport (ONT)

View £95 flight on Sat, 6 Jun 2026Opens in a new window

Popular airlines from Seattle-Tacoma International Airport (SEA) to Los Angeles - 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 £95 for one-way flights and £153 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Thu, 21 May - Sat, 30 May
SEA
Seattle
ONT
Ontario
£153 Return, found 4 days ago
£153
Return
found 4 days ago
Select Delta flight, departing Thu, 21 May from Seattle to Ontario, returning Sat, 30 May, priced at £153 found 4 days ago
Delta
Wed, 27 May - Sat, 30 May
SEA
Seattle
ONT
Ontario
£161 Return, found 4 days ago
£161
Return
found 4 days ago
Select Delta flight, departing Wed, 27 May from Seattle to Ontario, returning Sat, 30 May, priced at £161 found 4 days ago
Delta
Thu, 28 May - Sat, 30 May
SEA
Seattle
ONT
Ontario
£168 Return, found 4 days ago
£168
Return
found 4 days ago
Select Delta flight, departing Thu, 28 May from Seattle to Ontario, returning Sat, 30 May, priced at £168 found 4 days ago
Delta
Mon, 25 May - Mon, 1 Jun
SEA
Seattle
ONT
Ontario
£176 Return, found 4 days ago
£176
Return
found 4 days ago
Select Delta flight, departing Mon, 25 May from Seattle to Ontario, returning Mon, 1 Jun, priced at £176 found 4 days ago
Delta
Wed, 3 Jun - Thu, 18 Jun
SEA
Seattle
ONT
Ontario
£191 Return, found 1 day ago
£191
Return
found 1 day ago
Select Delta flight, departing Wed, 3 Jun from Seattle to Ontario, returning Thu, 18 Jun, priced at £191 found 1 day ago
Delta
Mon, 1 Jun - Thu, 18 Jun
SEA
Seattle
ONT
Ontario
£198 Return, found 1 day ago
£198
Return
found 1 day ago
Select Delta flight, departing Mon, 1 Jun from Seattle to Ontario, returning Thu, 18 Jun, priced at £198 found 1 day ago
Alaska Airlines
Sat, 30 May - Sun, 31 May
SEA
Seattle
ONT
Ontario
£214 Return, found 4 days ago
£214
Return
found 4 days ago
Select Alaska Airlines flight, departing Sat, 30 May from Seattle to Ontario, returning Sun, 31 May, priced at £214 found 4 days ago
Alaska Airlines
Fri, 22 May - Thu, 28 May
SEA
Seattle
ONT
Ontario
£234 Return, found 3 days ago
£234
Return
found 3 days ago
Select Alaska Airlines flight, departing Fri, 22 May from Seattle to Ontario, returning Thu, 28 May, priced at £234 found 3 days ago
Alaska Airlines
Mon, 15 Jun - Mon, 22 Jun
SEA
Seattle
ONT
Ontario
£235 Return, found 1 day ago
£235
Return
found 1 day ago
Select Alaska Airlines flight, departing Mon, 15 Jun from Seattle to Ontario, returning Mon, 22 Jun, priced at £235 found 1 day ago
Alaska Airlines
Mon, 15 Jun - Mon, 22 Jun
SEA
Seattle
ONT
Ontario
£251 Return, found 1 day ago
£251
Return
found 1 day ago
Select Alaska Airlines flight, departing Mon, 15 Jun from Seattle to Ontario, returning Mon, 22 Jun, priced at £251 found 1 day 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 £308
SNA
John Wayne
Cheapest
Average driving time to city centre42 min
Flights from £308

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

May is typically the cheapest month to fly

From £75 - £143 per traveller.

Frequently asked questions

How much does a flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) cost?
One-way flights typically cost between £80 and £397 and return flights often range between £80 and £397. 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 the cheapest fares first, and use the Price Tracking tool to receive alerts when Anaa (AAA) to Toronto, ON (YYZ-Pearson Intl.) ticket fares go up or down.
What is the cheapest month to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
January is typically the cheapest month to fly from Seattle - Tacoma Intl. (SEA) to Los Angeles - Ontario Intl. (ONT), with average return fares of approximately £187. This is about 16% lower than the average price throughout the year. January often sees lower prices because it falls after the busy holiday travel season, when demand tends to decrease. Other cheap months to fly from Seattle - Tacoma Intl. (SEA) to Los Angeles - Ontario Intl. (ONT) include February and September.
Which airlines fly direct from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
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, CA (ONT-Los Angeles - Ontario Intl.)?
To find a cheap flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.), 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, CA (ONT-Los Angeles - Ontario Intl.)?
The best airline to fly with from Seattle, WA (SEA-Seattle - Tacoma Intl.) (SEA) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) (ONT) will differ from traveller to traveller. If you like to fly early, DL offers early morning flights. If price is the most important factor, F9 typically offers the lowest fares. WN offers the most daily flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) (SEA) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) (ONT), which is brilliant 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-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
When looking for the best time to fly from Seattle - Tacoma Intl. (SEA) to Los Angeles - Ontario Intl. (ONT), you'll find that January and September are typically the cheapest months, with average return flights around £187. However, the most popular months for this route are June and February, which means you'll have plenty of flight options during those times. Since there isn't a single month that is both cheapest and most popular, you can choose based on your priorities: opt for January or September for the best value, or June and February if having a wide selection of flights is more important to you. This information is based on booking data from the past year.
How many flights per day from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
There are approximately 5 nonstop flights per day from Seattle - Tacoma Intl. (SEA) to Los Angeles - Ontario Intl. (ONT). For even more choice, look at flights that include layovers. You'll find around 47 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, CA (ONT-Los Angeles - Ontario Intl.)?
The earliest flight from Seattle - Tacoma Intl. (SEA) to Los Angeles - Ontario Intl. (ONT) typically departs at approximately 12:20 AM local time, operated by American Airlines. This is a seasonal service active in August. An early departure like this can help maximise 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, CA (ONT-Los Angeles - Ontario Intl.)?
You'll typically find the most flights from Seattle - Tacoma Intl. (SEA) to Los Angeles - Ontario Intl. (ONT) on a Friday, with around 60 flights available. This gives you plenty of options for your travel plans. Major airlines on this route include Alaska Airlines, Southwest Airlines, and United Airlines. Friday offers notably more flight options compared to other days of the week.
What are the most popular departure times for flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
The most popular departure times for flights from Seattle - Tacoma Intl. (SEA) to Los Angeles - Ontario Intl. (ONT) are in the early morning, from 6am to 9am. This accounts for around 26% of total traffic. Many major carriers, including Southwest Airlines, Alaska Airlines and Delta Air Lines, offer flights during this window. Many travelers prefer these times because they allow for an early start to your day at your destination.
How long does it take to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
A nonstop flight from SEA to ONT typically takes around 2 hours 50 minutes, covering approximately 957 miles. Connecting flights on this route usually add 2 hours 10 minutes to your travel time. 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, CA (ONT-Los Angeles - Ontario Intl.)?
Select the "Business class" and "First class" filters when looking for SEA to ONT flights on Expedia. This is the easiest way to compare prices, routes and flight times for your trip.
How do I earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight with Expedia?
It's easy to earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) 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 from Seattle - Tacoma Intl. (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), Norman Y. Mineta San Jose Intl. (SJC) 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-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) at the last minute?
Typically, booking a last minute flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) 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-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight and hotel package?
Securing a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) 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, CA (ONT-Los Angeles - Ontario Intl.)?
If you booked your Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) 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, Delta
Return price
£153
Distance
1530 km
Average flight time
2 hours 45 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 £153 and range up to £251.  

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 May, 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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*Available to Expedia members.