Cheap flights from Ontario to Seattle (ONT - SEA) from $39
This is the cheapest one-way flight price, found on 9/27. Prices may vary by date and flight preferences.
The best prices from Ontario to Seattle/Tacoma Intl are usually found in January or February, booked 41 days in advance, depart on a Monday or Wednesday and return on a Tuesday
How to find the cheapest flight from Ontario (ONT) to Seattle (SEA)
All the information you need to plan the best ONT to SEA flight in 2023: compare Ontario to Seattle flight prices with the expected peak season, weather and rainfall in Seattle.
Popular in | July |
|---|---|
Cheapest in | January |
Round-trip from | $237 |
One-way from | $60 |
ONT - SEA Price | $237 - $457 |
|---|---|
SEA Temperature | 41 - 66.2 °F |
SEA Rainfall | 0.7 - 6.6 inches |
What is the cheapest day to fly round-trip from Ontario to Seattle?
Flights from Ontario to Seattle are found to be more expensive on Saturday. This shouldn't discourage you from searching as you can still find great deals by being flexible with your options. Use our search form to find deals on tickets to Seattle.
How far in advance should I book a flight from Ontario to Seattle?
Users have found that booking a flight from Ontario to Seattle at least 35 days early can save you up to 95% on average compared to booking a flight this week. If booking 35 days before your flight isn’t an option for you, users have found flights from Ontario to Seattle for as little as $381 when booking for a departure date within the next two weeks. You can also check prices now. Some users have found airline tickets as low as $559 for flights departing within the next 3 days.
What is the cheapest month to fly from Ontario to Seattle?
January can be a great time to fly to Seattle from Ontario with a flight ticket averaging about $282. Cheapflights users have found deals in the month of January for as cheap as $158. The most expensive prices can be found in the month of July.
When is the cheapest time to fly from Ontario to Seattle (ONT - SEA)?
It’s typically best to fly out from Ontario to Seattle in the evening. Doing so could potentially save you 34% on the flight price compared to flying at noon, which is usually more expensive.
Cheap Alaska Airlines flights from Ontario to Seattle
Take a peek at the cheapest Alaska Airlines flights we've detected traveling from Ontario to Seattle. It's recommended that users confirm their flight details before booking.
Alaska Airlines is one of the most popular airlines used for those traveling from Ontario to Seattle. Flights on this route from Alaska Airlines typically cost $217.80 RT, a price that is 45% cheaper than the average Ontario to Seattle flight. The cheapest flight found was $84 RT. Ontario Airport is the most common Ontario airport to take off from when flying to Seattle. Seattle/Tacoma Intl Airport is the most popular arrival airport in Seattle. When flying from Ontario to Seattle, Alaska Airlines flights are 13% more popular than any other airline flying that same route.
Cheap Frontier flights from Ontario to Seattle
Some of the lowest-priced Frontier flights we've found at this time heading from Ontario to Seattle. If these deals don't fit your criteria, make sure to check back soon as new deals are always added.
One of the most popular airlines traveling from Ontario to Seattle is Frontier. Flights from Frontier traveling this route typically cost $217.81 RT. This price is typically 36% cheaper than other airlines that offer Ontario to Seattle flights. When booking this route, the cheapest RT price found was $84. Ontario Airport is the most common Ontario airport to take off from when flying to Seattle. Seattle/Tacoma Intl Airport is the most popular arrival airport in Seattle. When flying from Ontario to Seattle, Frontier flights are 11% more popular than any other airline flying that same route.
Cheap Ontario to Seattle flights in September & October 2023
The best prices found for ONT to SEA flights for September, October
Listed are some of the best fares we've found on flights departing from Ontario to Seattle in 2023. For more flight deals, be sure to check back very soon.
Ontario to Seattle 2023 flight deals
Cheap flights to Seattle from Ontario found for this year
Listed are some of the best fares we've found on flights departing from Ontario to Seattle in 2023. For more flight deals, be sure to check back very soon.
Non-stop flights to Seattle from Ontario
Save time with Ontario to Seattle direct flight deals
For a quicker trip, book one of these direct flights from Ontario to Seattle. Select from other flights from Ontario to Seattle by using the search form above.
Ontario to Seattle flights leaving soon
Late deals on return flights to Seattle from Ontario, departing today and this week
Have a look at some of the last-minute flights available departing from Ontario to Seattle. Users should be sure to double check the price, date, and time of their last-minute flight.
One-way flights to Seattle from Ontario
The cheapest one-way flights from Ontario to Seattle
Users traveling one-way from Ontario to Seattle can select one of these great deals. Users in need of a round-trip flight from Ontario to Seattle instead should update the search form at the top of page.
Find flights from Ontario to Seattle within your budget
Use the slider to find flights from Ontario to Seattle that fit your budget.
Fly from
Fly to
Budget
$78 - $172
Route
Depart
Return
Price
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Thu 10/26
1 stop13h 13m
Seattle/Tacoma Intl
Tue 10/31
1 stop14h 40m
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Fri 11/10
1 stop11h 40m
Seattle/Tacoma Intl
Tue 11/14
1 stop4h 55m
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Fri 10/27
1 stop27h 22m
Seattle/Tacoma Intl
Tue 10/31
1 stop4h 54m
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Fri 10/27
1 stop27h 22m
Seattle/Tacoma Intl
Mon 10/30
1 stop15h 24m
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Tue 10/10
1 stop12h 06m
Seattle/Tacoma Intl
Tue 10/17
1 stop10h 00m
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Fri 12/1
1 stop7h 30m
Seattle/Tacoma Intl
Sat 12/9
1 stop7h 51m
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Sat 10/28
Nonstop2h 46m
Seattle/Tacoma Intl
Tue 10/31
Nonstop2h 30m
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Fri 10/27
Nonstop2h 49m
Seattle/Tacoma Intl
Mon 10/30
Nonstop2h 30m
OntarioSeattle/Tacoma Intl
ONT - SEA
ONTSEA
Ontario
Sat 2/3
1 stop7h 11m
Seattle/Tacoma Intl
Tue 2/6
1 stop6h 36m
Reviews of airlines servicing Seattle
Read reviews from past customers who have flown Alaska Airlines, Frontier and American Airlines from Ontario to Seattle. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Entertainment
Food
Overall
Boarding
Crew
Comfort
Reviews
Was forced to check my bag, didn’t want to but really upset when got on the plane and nearly all the overheads were empty. And then even more upset when they lost my bag! So far it’s been 5 hours and they have no clue where my bag went. Don’t force me to check a normal carry on when there’s more than enough room!
Entertainment
Food
Overall
Boarding
Crew
Comfort
Reviews
Was forced to check my bag, didn’t want to but really upset when got on the plane and nearly all the overheads were empty. And then even more upset when they lost my bag! So far it’s been 5 hours and they have no clue where my bag went. Don’t force me to check a normal carry on when there’s more than enough room!
Entertainment
Food
Overall
Boarding
Crew
Comfort
Reviews
Was forced to check my bag, didn’t want to but really upset when got on the plane and nearly all the overheads were empty. And then even more upset when they lost my bag! So far it’s been 5 hours and they have no clue where my bag went. Don’t force me to check a normal carry on when there’s more than enough room!
Entertainment
Food
Overall
Boarding
Crew
Comfort
Reviews
Was forced to check my bag, didn’t want to but really upset when got on the plane and nearly all the overheads were empty. And then even more upset when they lost my bag! So far it’s been 5 hours and they have no clue where my bag went. Don’t force me to check a normal carry on when there’s more than enough room!
Entertainment
Food
Overall
Boarding
Crew
Comfort
Reviews
Was forced to check my bag, didn’t want to but really upset when got on the plane and nearly all the overheads were empty. And then even more upset when they lost my bag! So far it’s been 5 hours and they have no clue where my bag went. Don’t force me to check a normal carry on when there’s more than enough room!
Entertainment
Food
Overall
Boarding
Crew
Comfort
Reviews
Was forced to check my bag, didn’t want to but really upset when got on the plane and nearly all the overheads were empty. And then even more upset when they lost my bag! So far it’s been 5 hours and they have no clue where my bag went. Don’t force me to check a normal carry on when there’s more than enough room!
Related info for your journey
Useful info, stats and facts about Ontario to Seattle flights.
What airports do I use to fly from Ontario to Seattle?
If you wish to fly to Seattle from Ontario, then you need to book flights from Ontario to Seattle/Tacoma Intl. There are 12 flights from Ontario (ONT) to Seattle/Tacoma Intl (SEA) per day to choose from. Flights to Seattle from Ontario are available from 8 different airlines, which means you should have some options if you want to compare airfare deals. 2h 40m is how long a nonstop flight from Ontario to Seattle/Tacoma Intl typically takes.
Can I find flights from Ontario to Seattle for under $100 on Cheapflights?
Yes, there are multiple flights from Ontario to Seattle for under $100. The cheapest flight booked recently is on Frontier for just $78, but on average you can expect to pay $92.
Are there nonstop flights from Ontario to Seattle for under $100 on Cheapflights?
Cheapflights has at least 20 direct flights from Ontario to Seattle under $100. A good price for a nonstop flight from Ontario to Seattle is less than $139.
Are there last-minute flights available from Ontario to Seattle for under $100?
There are currently 20+ open flights from Ontario to Seattle within the next 7 days for less than $100.
What days are nonstop flights available from Ontario to Seattle?
Nonstop flights are available for this route on the following days: Sunday, Monday, Tuesday, Thursday, Friday, Saturday.
How popular is this Ontario to Seattle flight route?
The Ontario to Seattle/Tacoma Intl flight path was viewed by 71 users in the past month. Keep an eye out for changes in search interest prior to high and low season.
How many flights depart from Ontario to Seattle on average per day?
On average 26 flights depart from Ontario to Seattle per day.
Early Morning (Midnight to 6am) - 54% of flight departures
Morning (6am - Noon) - 15% of flight departures
Afternoon (Noon - 6pm) - 12% of flight departures
Evening (6pm - Midnight) - 19% of flight departures
How long is the flight from Ontario to Seattle?
There are many flights that can get you from Ontario to Seattle in 2h 46m. Fly via Frontier or Alaska Airlines to get the fastest option. There are 962 mi between Ontario and Seattle. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.
What are the cheapest airlines flying from Ontario to Seattle round-trip?
Cheapflights users have booked flights from Ontario to Seattle round-trip from $78. Another airline that can offer you cheap pricing is Alaska Airlines. You may be able to fly from Ontario to Seattle for 70% less than the average price by searching for these airlines.
What are the cheapest airlines to fly from Ontario to Seattle one-way?
The cheapest airlines for a one-way flight from Ontario to Seattle are Frontier ($39), Alaska Airlines ($59), and Delta ($89).
What are the most popular airlines that fly from Ontario to Seattle?
Undisclosed Carrier, American Airlines and Alaska Airlines are the most popular airlines when flying from Ontario to Seattle.
What are the most reliable airlines from Ontario to Seattle?
Consider WestJet (98%), SkyWest Airlines (94%) or Japan Airlines (92%) when booking your flight. These represent the most reliable airlines when flying from Ontario to Seattle.
What are the cheapest flights from Ontario to Seattle?
While on average a flight from Ontario to Seattle is generally $492, our data shows the cheapest flight currently is $69. When looking at the most popular route, (Ontario - Seattle/Tacoma Intl), you can expect to pay $78 for that flight.
What does ONT to SEA mean?
Great question - ONT to SEA just means Ontario Airport to Seattle/Tacoma Intl Airport. Now you’ll know what these unique codes when you look for flights!
Other flights from Ontario
Flights to Seattle from Ontario
Alternative routes for Ontario to Seattle
See prices for flight routes from nearby airports that may be better suited for you.
Top 7 airlines flying from Ontario to Seattle
The chart below displays the airlines Cheapflights users traveling from Ontario to Seattle choose most often. Cheapest and average prices are based on aggregated data from the past 12 months.
Hourly flight availability from Ontario to Seattle
See what time of day planes typically take off from Ontario to Seattle
| 22%of flight departures | Early morningMidnight to 6 am |
|---|---|
| 44%of flight departures | Morning6 am to noon |
| 20%of flight departures | AfternoonNoon to 6 pm |
| 14%of flight departures | Evening6 pm to midnight |
Weekly flight availability from Ontario to Seattle
See how many times per day planes take to the skies headed from Ontario to Seattle
| Sunday | 14daily flights |
|---|---|
| Monday | 15daily flights |
| Tuesday | 11daily flights |
| Wednesday | 10daily flights |
| Thursday | 12daily flights |
| Friday | 15daily flights |
| Saturday | 9daily flights |
Fly with Cheapflights
What makes Cheapflights the go-to destination for all your flight needs
How does Cheapflights help users find flights from Ontario to Seattle?
Cheapflights goes through 900+ travel sites to look for the best flight deals for flights from Ontario to Seattle. Too many options? Cheapflights also provides filters for things like airlines, price ranges, and number of stops to help you make a decision easily.
Why should you use Cheapflights to find cheap flight tickets from Ontario to Seattle?
Cheapflights helps you find that perfect flight to Seattle from Ontario by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!
Can Cheapflights find flights from Ontario to Seattle with no change fees?
Cheapflights does show flights with no change fees to all users. To see these options for flights from Ontario to Seattle, users can toggle the no change fees filter when performing a flight search.
Can Cheapflights notify me if prices for flights from Ontario to Seattle become cheaper?
Yes, Cheapflights does offer price alerts on Ontario to Seattle flights so you can book your travels when it’s right. The Price Alert feature is available after a flight search is performed above.