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Cheap flights from Ontario to Seattle from $28

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to Seattle departing on 2/6. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Ontario to Seattle

Cheap round-trip flights

These are some of the best round-trip flight deals from Ontario to Seattle that have been recently found on momondo from popular airlines, departing in the coming months.

Cheap one-way flights

Flying one-way? These are some of the best deals recently discovered on momondo for flights from Ontario to Seattle.

Cheap last minute flights

Planning a quick getaway from Ontario to Seattle? These are the last-minute flight deals available now.

Cheap direct flights

If you prefer a non-stop journey, check out our latest direct flight deals to Seattle, so you can enjoy a seamless trip without layovers.

Cheap bus & train deals from Ontario to Seattle

Find recent round-trip train or bus tickets from Ontario to Seattle.

All round-trip flight deals to Seattle

The cheapest plane tickets to Seattle found on KAYAK recently.
7:59 am - 10:59 amONT-SEA
3h 00mnonstop
7:21 pm - 9:59 pmSEA-ONT
2h 38mnonstop
$45Frontier
Find Deal
Tue, Dec 17 - Tue, Dec 17
11:25 am - 2:16 pmONT-SEA
2h 51mnonstop
1:36 pm - 4:13 pmSEA-ONT
2h 37mnonstop
$57Frontier
Find Deal
Thu, Feb 20 - Mon, Mar 3
11:25 am - 2:16 pmONT-SEA
2h 51mnonstop
1:36 pm - 4:13 pmSEA-ONT
2h 37mnonstop
$58Frontier
Find Deal
Thu, Feb 20 - Mon, Feb 24
6:00 am - 8:54 amONT-SEA
2h 54mnonstop
8:00 am - 10:38 amSEA-ONT
2h 38mnonstop
$109Alaska Airlines
Find Deal
Sat, Jan 11 - Sun, Jan 12
6:00 am - 8:54 amONT-SEA
2h 54mnonstop
3:40 pm - 6:13 pmSEA-ONT
2h 33mnonstop
$111Alaska Airlines
Find Deal
Sat, Jan 11 - Mon, Jan 13
6:00 am - 8:55 amONT-SEA
2h 55mnonstop
7:45 pm - 10:32 pmSEA-ONT
2h 47mnonstop
$118Delta
Find Deal
Sat, Jan 11 - Mon, Jan 13
7:00 am - 12:51 pmONT-SEA
5h 51m1 stop
4:35 pm - 7:12 pmSEA-ONT
2h 37mnonstop
Fri, Jan 17 - Sun, Jan 19
5:10 pm - 12:50 amONT-SEA
7h 40m1 stop
7:45 pm - 10:32 pmSEA-ONT
2h 47mnonstop
$127Delta
Find Deal
Tue, Jan 7 - Tue, Jan 21
11:27 am - 2:18 pmONT-SEA
2h 51mnonstop
8:05 pm - 10:39 pmSEA-ONT
2h 34mnonstop
Thu, Jan 16 - Mon, Jan 20
10:47 am - 3:45 pmONT-SEA
4h 58m1 stop
12:50 pm - 8:29 pmSEA-ONT
7h 39m1 stop
$246United Airlines
Find Deal
Fri, Jan 10 - Mon, Jan 13
11:27 am - 2:18 pmONT-SEA
2h 51mnonstop
$28Frontier
Find Deal
Thu, Feb 6
11:25 am - 2:16 pmONT-SEA
2h 51mnonstop
$29Frontier
Find Deal
Thu, Feb 27
6:00 am - 8:55 amONT-SEA
2h 55mnonstop
$59Delta
Find Deal
Fri, Jan 31
1:21 pm - 6:46 pmONT-SEA
5h 25m1 stop
$68Delta
Find Deal
Fri, Jan 31
7:00 am - 12:16 pmONT-SEA
5h 16m1 stop
$78Alaska Airlines
Find Deal
Wed, Mar 5
5:44 pm - 9:02 amONT-SEA
15h 18m1 stop
$97Alaska Airlines
Find Deal
Tue, Mar 4
6:15 am - 11:20 amONT-SEA
5h 05m1 stop
$123United Airlines
Find Deal
Mon, Feb 3
11:46 am - 2:53 pmONT-SEA
27h 07m1 stop
Mon, Dec 9
6:00 am - 10:46 amONT-SEA
4h 46m1 stop
$158United Airlines
Find Deal
Fri, Dec 13
9:23 pm - 12:10 amONT-SEA
26h 47m2 stops
Mon, Dec 9
11:09 am - 2:09 pmONT-SEA
3h 00mnonstop
12:29 pm - 3:08 pmSEA-ONT
2h 39mnonstop
$151Frontier
Find Deal
Thu, Dec 5 - Thu, Dec 12
11:09 am - 2:09 pmONT-SEA
3h 00mnonstop
7:21 pm - 9:59 pmSEA-ONT
2h 38mnonstop
$173Frontier
Find Deal
Thu, Dec 5 - Tue, Dec 17
11:09 am - 2:09 pmONT-SEA
3h 00mnonstop
6:30 pm - 9:04 pmSEA-ONT
2h 34mnonstop
Thu, Dec 5 - Sat, Dec 14
11:09 am - 2:09 pmONT-SEA
3h 00mnonstop
2:48 pm - 5:21 pmSEA-ONT
2h 33mnonstop
Thu, Dec 5 - Tue, Dec 10
6:00 am - 8:53 amONT-SEA
2h 53mnonstop
5:28 pm - 8:00 pmSEA-ONT
2h 32mnonstop
$327Alaska Airlines
Find Deal
Sat, Dec 7 - Tue, Dec 17
1:50 pm - 4:56 pmONT-SEA
3h 06mnonstop
8:35 am - 11:20 amSEA-ONT
2h 45mnonstop
$332Delta
Find Deal
Sat, Dec 7 - Sat, Dec 14
6:10 pm - 9:00 pmONT-SEA
2h 50mnonstop
5:28 pm - 8:00 pmSEA-ONT
2h 32mnonstop
$337Alaska Airlines
Find Deal
Sat, Dec 7 - Wed, Dec 11
1:50 pm - 4:56 pmONT-SEA
3h 06mnonstop
9:30 am - 4:30 pmSEA-ONT
7h 00m1 stop
$342Delta
Find Deal
Sat, Dec 7 - Sat, Dec 14
6:00 am - 10:52 amONT-SEA
4h 52m1 stop
9:25 am - 2:33 pmSEA-ONT
5h 08m1 stop
$376United Airlines
Find Deal
Thu, Dec 5 - Tue, Dec 10
3:20 pm - 9:09 pmONT-SEA
5h 49m1 stop
5:00 am - 9:58 amSEA-ONT
4h 58m1 stop
$416United Airlines
Find Deal
Sat, Dec 7 - Thu, Dec 19
7:59 am - 10:59 amONT-SEA
3h 00mnonstop
7:21 pm - 9:59 pmSEA-ONT
2h 38mnonstop
$45Frontier
Find Deal
Tue, Dec 17 - Tue, Dec 17
11:09 am - 2:09 pmONT-SEA
3h 00mnonstop
7:21 pm - 9:59 pmSEA-ONT
2h 38mnonstop
$53Frontier
Find Deal
Thu, Dec 12 - Tue, Dec 17
11:27 am - 2:18 pmONT-SEA
2h 51mnonstop
4:35 pm - 7:12 pmSEA-ONT
2h 37mnonstop
$57Frontier
Find Deal
Thu, Jan 16 - Thu, Jan 23
11:25 am - 2:16 pmONT-SEA
2h 51mnonstop
1:36 pm - 4:13 pmSEA-ONT
2h 37mnonstop
$58Frontier
Find Deal
Thu, Feb 20 - Mon, Feb 24
6:00 am - 8:54 amONT-SEA
2h 54mnonstop
3:40 pm - 6:13 pmSEA-ONT
2h 33mnonstop
$104Alaska Airlines
Find Deal
Sat, Jan 11 - Mon, Jan 13
6:00 am - 8:54 amONT-SEA
2h 54mnonstop
8:00 am - 10:38 amSEA-ONT
2h 38mnonstop
$109Alaska Airlines
Find Deal
Sat, Jan 11 - Sun, Jan 12
7:01 pm - 9:53 pmONT-SEA
2h 52mnonstop
4:35 pm - 7:12 pmSEA-ONT
2h 37mnonstop
Fri, Jan 17 - Sun, Jan 19
4:05 pm - 7:00 pmONT-SEA
2h 55mnonstop
7:45 pm - 10:32 pmSEA-ONT
2h 47mnonstop
$118Delta
Find Deal
Sat, Jan 11 - Mon, Jan 13
6:00 am - 8:55 amONT-SEA
2h 55mnonstop
7:59 am - 10:47 amSEA-ONT
2h 48mnonstop
$127Delta
Find Deal
Fri, Feb 28 - Tue, Mar 18
6:00 am - 8:50 amONT-SEA
2h 50mnonstop
1:36 pm - 4:13 pmSEA-ONT
2h 37mnonstop
Sat, Mar 8 - Sun, Mar 9

Alaska Airlines flights from Ontario to Seattle

Our best Alaska Airlines deals on Ontario to Seattle flight tickets
Alaska Airlines
Jan 11
ONT6:00 amOntario
2h 54m
SEA8:54 amSeattle/Tacoma Intl
Jan 12
SEA8:00 amSeattle/Tacoma Intl
2h 38m
ONT10:38 amOntario
Alaska Airlines
Jan 11
ONT6:00 amOntario
2h 54m
SEA8:54 amSeattle/Tacoma Intl
Jan 13
SEA3:40 pmSeattle/Tacoma Intl
2h 33m
ONT6:13 pmOntario
Alaska Airlines
Jan 18
ONT6:00 amOntario
2h 54m
SEA8:54 amSeattle/Tacoma Intl
Jan 19
SEA8:00 amSeattle/Tacoma Intl
2h 38m
ONT10:38 amOntario

Delta flights from Ontario to Seattle

Our best Delta deals on Ontario to Seattle flight tickets
Delta
Jan 11
ONT6:00 amOntario
2h 55m
SEA8:55 amSeattle/Tacoma Intl
Jan 13
SEA7:45 pmSeattle/Tacoma Intl
2h 47m
ONT10:32 pmOntario
Delta
Jan 7
ONT5:10 pmOntario
7h 40m
1 stop
SEA12:50 amSeattle/Tacoma Intl
Jan 21
SEA7:45 pmSeattle/Tacoma Intl
2h 47m
ONT10:32 pmOntario
Delta
Jan 11
ONT6:00 amOntario
6h 25m
1 stop
SEA12:25 pmSeattle/Tacoma Intl
Jan 13
SEA7:45 pmSeattle/Tacoma Intl
2h 47m
ONT10:32 pmOntario

See travel insights to Seattle from

How to get the cheapest flight ticket from Ontario to Seattle

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Ontario and Seattle?

What is the cheapest month to fly to Seattle?

In general, October is the cheapest month to fly from Ontario to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $176. If you don’t want to visit Seattle in October, then you should wait until September to fly from Ontario, when ticket prices are also cheap, with an average price of $177.

What is the cheapest day to depart on your flight to Seattle?

On average, the least expensive day to fly to Seattle from Ontario is on a Tuesday. momondo users have found tickets for Tuesday departures for as low as $221. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Sunday is the most expensive day to depart from Ontario because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $266.

What is the cheapest time of day to depart on your flight to Seattle?

Flying to Seattle from Ontario at noon is the least expensive time of day to depart. momondo users have found prices as low as $218 when looking at flights departing at noon. Flights to Seattle are more costly in the morning, with an average ticket price of $248. Departure times in the morning fall within the peak daily travel times, which is why tickets can be more expensive.

What is the cheapest Ontario to Seattle/Tacoma Intl flight route?

Fly from Ontario to Seattle/Tacoma Intl for the best Ontario - Seattle/Tacoma Intl flight prices

How far in advance should I book a flight to Seattle?

You are more likely to see cheaper flights to Seattle from Ontario when booking 47 days ahead of your departure date. In general, you can expect to find flights to Seattle for around $231 when searching 47 days out. Keep in mind that you might be able to find cheaper flights to Seattle at any time. In fact, our users found flights for as low as $176 in the past 72 hours.

What cabin class options are available on Ontario to Seattle/Tacoma Intl flights?

There are 4 cabin classes available to choose from on Ontario to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Ontario to Seattle flights?

You could potentially save up to 92% on your flight if you consider stops on a Ontario to Seattle flight.

How have Ontario to Seattle flight prices changed over time?

As of December 2024, prices for Ontario to Seattle flights are approximately 20% cheaper when compared to flights at the same time last year.

When to book flights from Ontario to Seattle

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to Seattle according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Ontario to Seattle (ONT to SEA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to Seattle

Best Price Found

$28

Fastest flight time

2h 47m

Direct flights

Every day

Airports in Seattle

1 airport
The best one-way flight to Seattle from Ontario in the past 72 hours is $28. The best round-trip flight deal from Ontario to Seattle found on momondo in the last 72 hours is $45.
The fastest flight from Ontario to Seattle takes 2h 47m
Direct flights go from Ontario to Seattle every day.
There is 1 airport near Seattle: Seattle/Tacoma Intl (SEA)

  • How far is Ontario to Seattle/Tacoma Intl by plane?

    The straight-line distance from Ontario to Seattle/Tacoma Intl is 966.6 mi. By plane, this route typically takes 2h 47m.

  • When did momondo last update prices for flights from Ontario Airport to Seattle/Tacoma Intl Airport?

    Prices for flights from Ontario Airport to Seattle/Tacoma Intl Airport are updated daily.

  • How many operators does momondo search for flights from Ontario Airport to Seattle/Tacoma Intl Airport?

  • How old do you have to be to fly from Ontario Airport to Seattle/Tacoma Intl Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario Airport to Seattle/Tacoma Intl Airport.

  • What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

    The necessary travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Ontario to Seattle?

  • What is the most popular airline from Ontario to Seattle?


Best airlines flying from Ontario to Seattle

Compare and see reviews for airlines that fly from Ontario to Seattle with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $62Free CancellationRating
6.1
3,508 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $71Free CancellationRating
6.3
8,151 reviews
Search Spirit Airlines flights
DeltaPriceFrom $104Free CancellationRating
8.0
8,698 reviews
Search Delta flights
Alaska AirlinesPriceFrom $125Free CancellationRating
8.0
9,508 reviews
Search Alaska Airlines flights
United AirlinesPriceFrom $243Free CancellationRating
7.4
9,141 reviews
Search United Airlines flights
  • Delta Flights From Ontario to Seattle

    Delta flight deals from Ontario to Seattle start from $104 round-trip. Over the 14 Delta flights for this route in a normal week, average airfare is usually $254 round-trip - but some users have found much cheaper deals with momondo.

  • Alaska Airlines Flights From Ontario to Seattle

    $125 is the best Alaska Airlines flight deal from Ontario to Seattle found on momondo over the last 72 hours. The average Alaska Airlines ticket price found was closer to $261, however, with flight time and availability significantly affecting the price. Alaska Airlines (8.0/10 from 9,508 user reviews) flies into Seattle from Ontario 5 times in an average week so prices can vary.


Why use momondo?

Why should I use momondo to find a flight deal from Ontario to Seattle?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Ontario to Seattle. momondo saves you time and could save you money on your trip.

Can I find flights from Ontario to Seattle with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to Seattle from Ontario with this policy.

How can momondo help me find flights from Ontario to Seattle?

momondo helps you find the best flight between Ontario and Seattle by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

I’m not ready to book a flight from Ontario to Seattle right now. Can momondo alert me if prices change?

Price alerts on flights to Seattle from Ontario are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.


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