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$56+ Cheap flights from Ontario to Seattle (ONT - SEA)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/19. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SEA
Nov 25 — Dec 21
Mon 11/25
Mon 12/2
1 adult, Economy
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The best prices from Ontario to Seattle/Tacoma Intl are usually found in October or September, booked 79 days in advance, depart on a Wednesday or Tuesday and return on a Tuesday

Cheap flight deals from Ontario to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated November 20, 2024.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Popular in

December

Cheapest in

October

Round-trip from

$93
(Frontier)

One-way from

$56
(Trip.com)
Provider with most accurate pricing for Ontario-Seattle/Tacoma Intl flight deals.
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Provider most trusted by Cheapflights users for Ontario-Seattle/Tacoma Intl flights.
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High demand for flights, 21% potential price rise
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Best time to find cheap flights, 22% potential price drop
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From Ontario to Seattle/Tacoma Intl
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One-way flight from Ontario to Seattle/Tacoma Intl
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Find flight deals from Ontario to Seattle

Cheapest flights from Ontario to Seattle
Explore the most affordable flight options available from Ontario to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 20, 2024.

This Cheapflightsfares deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/1511:09 amONT - SEA
Nonstop3h 00mFrontier
Tue 12/177:21 pmSEA - ONT
Nonstop2h 38mFrontier
Deal found 11/19$96
This Expedia deal was found by Cheapflights users on 11/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/410:11 pmONT - SEA
1 stop10h 46mMultiple Airlines
Wed 12/115:28 pmSEA - ONT
Nonstop2h 32mMultiple Airlines
Deal found 11/18$133
This Delta deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/105:50 amONT - SEA
Nonstop3h 05mDelta
Tue 12/177:45 amSEA - ONT
Nonstop2h 50mDelta
Deal found 11/19$137
This Alaska Airlines deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/106:00 amONT - SEA
Nonstop2h 53mAlaska Airlines
Tue 12/105:28 pmSEA - ONT
Nonstop2h 32mAlaska Airlines
Deal found 11/19$147
This United Airlines deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/106:28 pmONT - SEA
1 stop6h 22mUnited Airlines
Tue 12/1711:56 amSEA - ONT
1 stop5h 47mUnited Airlines
Deal found 11/19$196

Find flights from Ontario to Seattle within your budget

Customize your flight search to find flights from Ontario to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,629,791 searches. Data last updated November 20, 2024.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 3/18

9:35 am-12:22 pm

Nonstop2h 47m

Seattle/Tacoma Intl

Tue 3/25

1:22 pm-3:59 pm

Nonstop2h 37m

$93

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 12/4

10:11 pm-8:57 am

1 stop10h 46m

Seattle/Tacoma Intl

Wed 12/11

5:28 pm-8:00 pm

Nonstop2h 32m

$133

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 12/10

5:50 am-8:55 am

Nonstop3h 05m

Seattle/Tacoma Intl

Tue 12/17

7:45 am-10:35 am

Nonstop2h 50m

$137

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 1/7

6:00 am-8:54 am

Nonstop2h 54m

Seattle/Tacoma Intl

Tue 1/14

8:00 am-10:49 am

Nonstop2h 49m

$147

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 12/10

6:28 pm-12:50 am

1 stop6h 22m

Seattle/Tacoma Intl

Tue 12/17

11:56 am-5:43 pm

1 stop5h 47m

$196

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 12/19

4:26 pm-7:26 pm

Nonstop3h 00m

$56

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 2/19

6:00 am-8:55 am

Nonstop2h 55m

$69

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 1/14

11:14 am-4:00 pm

1 stop4h 46m

$78

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 1/21

6:15 am-11:20 am

1 stop5h 05m

$88

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 1/21

12:48 pm-8:00 pm

1 stop7h 12m

$118

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/19

Showing 1-10 of 11 results
1
2

Compare providers for flights from Ontario to Seattle

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to Seattle in November.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*1 star
CheapfaremartPrice Accuracy-Trust Score*1 star
Kiwi.comPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy1 starTrust Score*3 stars
CheapOairPrice Accuracy2 starsTrust Score*3 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
Justfly.comPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Ontario-Seattle flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-Seattle flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-Seattle flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-Seattle flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Ontario to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Ontario with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Travel insights for flights from Ontario to Seattle

Get recent, data-driven insights about flights from Ontario to Seattle including ideal travel times, pricing trends, and more.

How far ahead should I book a flight from Ontario to Seattle?

Use this chart to determine the optimal time to book a round-trip flight from Ontario to Seattle. Price data was last updated on November 15, 2024.

To ensure you get the cheapest price possible for a flight from Ontario to Seattle, you should look to book at least 79 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Ontario to Seattle?

Currently, January is the cheapest month in which you can book a flight from Ontario to Seattle (average of $238). Flying from Ontario to Seattle in July is currently the most expensive (average of $411). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from ONT to SEA?

Find hourly flight availability from Ontario to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated November 20, 2024.

It’s typically best to fly out from Ontario to Seattle in the morning. Doing so could potentially save you 14% on the flight price compared to flying in the afternoon, which is usually more expensive.

What is the cheapest day to fly from Ontario to Seattle?

Use this chart to determine the cheapest time to fly round-trip from Ontario to Seattle. Price data was last updated on November 10, 2024.

Travelers seeking maximum savings on their Ontario to Seattle flight should consider departing on Tuesday mornings when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Ontario to Seattle

Explore weekly flight availability from Ontario to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated November 20, 2024.

The most flights from ONT to SEA are scheduled on a Wednesday (17 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (5 on average).

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 0.7 - 6.6 inches per month. November is typically the wettest month, when rainfall can reach 6.6 in. July is typically the driest time to visit Seattle when rainfall is around 0.7 in.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 66.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 41.0 F).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated November 20, 2024.
Read reviews from past customers who have flown Delta, Frontier and United 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.
Southwest
8.1
Very good
5,014 reviews

Comfort

8.1

Crew

8.7

Entertainment

7.7

Boarding

8.2

Food

7.2

Overall

8.1

Reviews

1 / 10

Sheila did great! First time I have ever seen all three people in an exit row get out and read the safety information card AFTER the briefing. I like the boarding process. It seems a shame to UN-differentiate SW because of abuse of the early boarding process.

Southwest
8.1
Very good
5,014 reviews
Southwest
8.1
Very good
5,014 reviews

Comfort

8.1

Crew

8.7

Entertainment

7.7

Boarding

8.2

Food

7.2

Overall

8.1

Reviews

1 / 10

Sheila did great! First time I have ever seen all three people in an exit row get out and read the safety information card AFTER the briefing. I like the boarding process. It seems a shame to UN-differentiate SW because of abuse of the early boarding process.

Alaska Airlines
8.0
Very good
9,461 reviews
Southwest
8.1
Very good
5,014 reviews

Comfort

8.1

Crew

8.7

Entertainment

7.7

Boarding

8.2

Food

7.2

Overall

8.1

Reviews

1 / 10

Sheila did great! First time I have ever seen all three people in an exit row get out and read the safety information card AFTER the briefing. I like the boarding process. It seems a shame to UN-differentiate SW because of abuse of the early boarding process.

Delta
8.0
Very good
8,756 reviews
Southwest
8.1
Very good
5,014 reviews

Comfort

8.1

Crew

8.7

Entertainment

7.7

Boarding

8.2

Food

7.2

Overall

8.1

Reviews

1 / 10

Sheila did great! First time I have ever seen all three people in an exit row get out and read the safety information card AFTER the briefing. I like the boarding process. It seems a shame to UN-differentiate SW because of abuse of the early boarding process.

United Airlines
7.4
Good
9,171 reviews
Southwest
8.1
Very good
5,014 reviews

Comfort

8.1

Crew

8.7

Entertainment

7.7

Boarding

8.2

Food

7.2

Overall

8.1

Reviews

1 / 10

Sheila did great! First time I have ever seen all three people in an exit row get out and read the safety information card AFTER the briefing. I like the boarding process. It seems a shame to UN-differentiate SW because of abuse of the early boarding process.

Frontier
6.1
Okay
3,539 reviews
Southwest
8.1
Very good
5,014 reviews

Comfort

8.1

Crew

8.7

Entertainment

7.7

Boarding

8.2

Food

7.2

Overall

8.1

Reviews

1 / 10

Sheila did great! First time I have ever seen all three people in an exit row get out and read the safety information card AFTER the briefing. I like the boarding process. It seems a shame to UN-differentiate SW because of abuse of the early boarding process.

Related info for your journey

Find useful and relevant information for your journey from Ontario to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • 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 11 flights from Ontario (ONT) to Seattle/Tacoma Intl (SEA) per day to choose from. Flights to Seattle from Ontario are available from 6 different airlines, which means you should have some options if you want to compare airfare deals. 2h 47m is how long a nonstop flight from Ontario to Seattle/Tacoma Intl typically takes.

  • How popular is this Ontario to Seattle flight route?

    The Ontario to Seattle/Tacoma Intl flight path was viewed by 151 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • What are the cheapest airlines flying from Ontario to Seattle round-trip?

    Cheapflights users have booked flights from Ontario to Seattle round-trip from $93. Other airlines that can offer you cheap pricing are Alaska Airlines, from $137, and Delta, from $157. You may be able to fly from Ontario to Seattle for 52% 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 ($56), Delta ($69), and Alaska Airlines ($78).

  • What are the most reliable airlines from Ontario to Seattle?

    Consider Air France (100%), LATAM Airlines (100%) or ITA Airways (100%) 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 $441, our data shows the cheapest flight currently is $47. When looking at the most popular route, (Ontario - Seattle/Tacoma Intl), you can expect to pay $103 for that flight.

  • Can I find deals for flights from Ontario to Seattle that include hotel bookings?

    Yes. In addition to deals on Ontario to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Ontario to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to Seattle.

  • Can I find deals for business class flights from Ontario to Seattle?

    Yes. Cheapflights offers flight deals from Ontario to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Ontario to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Ontario to Seattle (average of $238). Flying from Ontario to Seattle in July is currently the most expensive (average of $411). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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Alternative routes for Ontario to Seattle

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Top 5 airlines flying from Ontario to Seattle

Discover the top 5 airlines that operate flights from Ontario to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,629,791 searches. Data last updated November 20, 2024.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$62Average$138FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$71Average$130FlexibilityNo cancel feeOn-time65%
DeltaCheapest$104Average$254FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$123Average$260FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$243Average$321FlexibilityNo cancel feeOn-time69%
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