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$54+ Cheap flights from Seattle to Ontario (SEA - ONT)

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 3/7. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ONT
Jan 22 — Jan 291
Wed 1/22
Wed 1/29
1 adult, Economy
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The best prices from Seattle/Tacoma Intl to Ontario are usually found in September or August, booked 71 days in advance, depart on a Tuesday or Thursday and return on a Wednesday

Cheap flight deals from Seattle to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Ontario (ONT). 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 January 17, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$118
(Trip.com)

One-way from

$54
(Cheapflightsfares)

Popular in

December

Cheapest in

September

Average price

$196
Provider with most accurate pricing for Seattle/Tacoma Intl-Ontario flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Ontario flights.
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From Seattle/Tacoma Intl to Ontario
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One-way flight from Seattle/Tacoma Intl to Ontario
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High demand for flights, 9% potential price rise
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Best time to find cheap flights, 3% potential price drop
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Average for round-trip flights in January 2025
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Find flight deals from Seattle to Ontario

Cheapest flights from Seattle to Ontario
Explore the most affordable flight options available from Seattle to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 17, 2025.

This Frontier deal was found by Cheapflights users on 1/16. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 1/264:35 pmSEA - ONT
Nonstop2h 37mFrontier
Thu 1/3011:27 amONT - SEA
Nonstop2h 51mFrontier
Deal found 1/16$118
This Delta deal was found by Cheapflights users on 1/16. 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.
Sat 3/17:45 pmSEA - ONT
Nonstop2h 47mDelta
Sat 3/86:00 amONT - SEA
Nonstop2h 55mDelta
Deal found 1/16$157
This Travelocity deal was found by Cheapflights users on 1/16. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/18:01 amSEA - ONT
Nonstop2h 38mMultiple Airlines
Sun 4/610:12 amONT - SEA
Nonstop2h 54mMultiple Airlines
Deal found 1/16$158
This Alaska Airlines deal was found by Cheapflights users on 1/16. 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.
Sun 3/28:25 amSEA - ONT
Nonstop2h 37mAlaska Airlines
Sat 3/86:00 amONT - SEA
Nonstop2h 50mAlaska Airlines
Deal found 1/16$167
This United Airlines deal was found by Cheapflights users on 1/16. 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.
Thu 2/63:25 pmSEA - ONT
1 stop5h 04mUnited Airlines
Mon 2/1010:47 amONT - SEA
1 stop4h 58mUnited Airlines
Deal found 1/16$248
This American Airlines deal was found by Cheapflights users on 1/16. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/296:10 amSEA - ONT
1 stop5h 48mAmerican Airlines
Wed 2/512:48 pmONT - SEA
1 stop7h 12mAmerican Airlines
Deal found 1/16$267

Find flights from Seattle to Ontario within your budget

Customize your flight search to find flights from Seattle to Ontario 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 2,558,603 searches. Data last updated January 17, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sun 1/26

4:35 pm-7:12 pm

Nonstop2h 37m

Ontario

Thu 1/30

11:27 am-2:18 pm

Nonstop2h 51m

$118

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 1/30

4:35 pm-7:12 pm

Nonstop2h 37m

Ontario

Tue 2/4

5:44 pm-10:00 pm

1 stop4h 16m

$142

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 2/5

5:40 pm-8:13 pm

Nonstop2h 33m

Ontario

Sat 2/15

6:00 am-8:50 am

Nonstop2h 50m

$157

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 2/6

7:45 pm-10:32 pm

Nonstop2h 47m

Ontario

Sun 2/9

6:00 am-8:55 am

Nonstop2h 55m

$178

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 2/6

3:25 pm-8:29 pm

1 stop5h 04m

Ontario

Mon 2/10

6:15 am-11:20 am

1 stop5h 05m

$248

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 1/29

6:10 am-11:58 am

1 stop5h 48m

Ontario

Wed 2/5

12:48 pm-8:00 pm

1 stop7h 12m

$267

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 2/20

12:52 pm-3:29 pm

Nonstop2h 37m

$54

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 4/19

8:01 am-10:39 am

Nonstop2h 38m

$76

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 4/16

7:59 am-10:47 am

Nonstop2h 48m

$79

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 2/20

9:20 am-2:29 pm

1 stop5h 09m

$124

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/16

Showing 1-10 of 12 results
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Compare providers for flights from Seattle to Ontario

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 Seattle to Ontario in January.
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
Kiwi.comPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy2 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star
CheapOairPrice Accuracy2 starsTrust Score*2 stars
GotogatePrice Accuracy2 starsTrust Score*2 stars
CheapTicketsDealPrice 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 Seattle-Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Ontario 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 Seattle-Ontario 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 Seattle to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Seattle 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 Seattle to Ontario

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

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

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Ontario. Price data was last updated on January 10, 2025.

The best time to book flights from Seattle to Ontario is 65 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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

Currently, August is the cheapest month in which you can book a flight from Seattle to Ontario (average of $246). Flying from Seattle to Ontario in March is currently the most expensive (average of $311). 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 SEA to ONT?

Find hourly flight availability from Seattle to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated January 17, 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Ontario at noon. If you’re flexible enough to do this you can expect to save up to 43% on your trip compared to booking a flight in the morning.

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

Use this chart to determine the cheapest time to fly round-trip from Seattle to Ontario. Price data was last updated on December 16, 2024.

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

Weekly flight availability from Seattle to Ontario

Explore weekly flight availability from Seattle to Ontario. 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 January 17, 2025.

The most flights from SEA to ONT are scheduled on a Thursday (17 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (6 on average).

Rainfall in Ontario by month

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

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

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

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated January 17, 2025.
Read through reviews of airlines operating flights from Seattle to Ontario, such as Delta, United Airlines and Alaska Airlines. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

Southwest
8.1
Very good
4,659 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

Alaska Airlines
8.0
Very good
9,681 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

Delta
8.0
Very good
8,511 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

United Airlines
7.4
Good
8,965 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

Related info for your journey

Find useful and relevant information for your journey from Seattle to Ontario. 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 Seattle to Ontario?

    Booking a flight from Seattle/Tacoma Intl (SEA) to Ontario (ONT) is your only option if you wish to fly from Seattle to Ontario. On a typical day, there are 10 flights from Seattle/Tacoma Intl to Ontario, all of which are around 2h 37m for a nonstop flight. You can also purchase a plane ticket from 4 airlines when you book a flight from Seattle/Tacoma Intl to Ontario.

  • How popular is this Seattle to Ontario flight route?

    This flight path from Seattle/Tacoma Intl to Ontario was viewed by 69 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 Seattle to Ontario round-trip?

    Our cheapest airline available from Seattle to Ontario is Frontier. Our recent data shows that you can find tickets from as low as $118 on this airline. Additional options worth looking into are Alaska Airlines and Delta, starting at $157 and $177 round-trip. Frontier is priced at 41% lower than the current average price of a flight leaving 3 months from now.