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$32+ Cheap flights from Ontario (ONT) to the United States

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 3/16. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LAX
Feb 5 — Feb 121
Thu 2/5
Thu 2/12
1 adult, Economy
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Cheap flight deals from Ontario to USA

Keep the following information in mind while searching for Ontario to USA flight deals. Data was last updated January 6, 2026.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$59
(CheapOair)

One-way from

$32
(Frontier)

Popular in

December

Cheapest in

January

Average price

$287

Good round-trip deal

$99 or less

Good one-way deal

$96 or less
Provider with most accurate pricing for Los Angeles-New York (NYC) flight deals.
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Provider most trusted by Cheapflights users for Los Angeles-New York (NYC) flights.
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From Ontario to USA
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One-way flight from Ontario to USA
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Highest demand for flights based on searches. 4% potential increase in price ($15 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
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Average for round-trip flights in January 2026
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Price to beat on a round-trip flight from Ontario to USA.
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Price to beat on a one-way flight from Ontario to USA.
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Find flight deals from Ontario to USA

Cheapest flights from Ontario to USA
Explore the most affordable flight options available from Ontario to USA. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 6, 2026.

This CheapOair deal was found by Cheapflights users on 1/6. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/43:07 pmONT - LAS
Nonstop1h 12mFrontier
Sun 2/86:24 pmLAS - ONT
Nonstop1h 08mFrontier
Deal found 1/6$59
This Agoda.com deal was found by Cheapflights users on 1/5. 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 Agoda.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 1/273:07 pmONT - LAS
Nonstop1h 12mFrontier
Thu 1/296:45 pmLAS - ONT
Nonstop1h 08mFrontier
Deal found 1/5$60
This CheapOair deal was found by Cheapflights users on 1/5. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/236:43 pmONT - LAS
Nonstop1h 09mFrontier
Mon 3/24:39 pmLAS - ONT
Nonstop1h 09mFrontier
Deal found 1/5$61
This Super.com deal was found by Cheapflights users on 1/6. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/293:22 pmONT - LAS
Nonstop1h 12mFrontier
Sun 2/16:24 pmLAS - ONT
Nonstop1h 08mFrontier
Deal found 1/6$62
This Mytrip deal was found by Cheapflights users on 1/6. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 1/313:04 pmONT - LAS
Nonstop1h 12mFrontier
Sun 2/86:24 pmLAS - ONT
Nonstop1h 08mFrontier
Deal found 1/6$63
This Priceline deal was found by Cheapflights users on 1/6. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/172:06 pmONT - LAS
Nonstop1h 14mFrontier
Thu 2/1912:00 pmLAS - ONT
Nonstop1h 11mFrontier
Deal found 1/6$65
This Super.com deal was found by Cheapflights users on 1/6. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/139:43 pmONT - LAS
Nonstop1h 10mFrontier
Sun 2/158:25 pmLAS - ONT
Nonstop1h 08mFrontier
Deal found 1/6$67
This CheapOair deal was found by Cheapflights users on 1/6. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 1/268:05 pmONT - LAS
Nonstop1h 08mFrontier
Fri 1/3012:21 pmLAS - ONT
Nonstop1h 11mFrontier
Deal found 1/6$70
This Alaska Airlines deal was found by Cheapflights users on 1/6. 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.
Thu 1/2911:53 amONT - SEA
Nonstop2h 51mAlaska Airlines
Sat 1/316:00 pmSEA - ONT
Nonstop2h 36mAlaska Airlines
Deal found 1/6$119
This Frontier deal was found by Cheapflights users on 1/6. 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.
Wed 3/48:40 amONT - IAH
1 stop8h 34mFrontier
Mon 3/97:04 pmIAH - ONT
Nonstop3h 49mFrontier
Deal found 1/6$120
This Delta deal was found by Cheapflights users on 1/6. 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.
Thu 1/291:11 pmONT - SEA
1 stop5h 18mDelta
Mon 2/27:00 pmSEA - ONT
1 stop4h 58mDelta
Deal found 1/6$120
This CheapOair deal was found by Cheapflights users on 1/5. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/182:06 pmONT - IAH
1 stop19h 59mFrontier
Mon 3/97:04 pmIAH - ONT
Nonstop3h 49mFrontier
Deal found 1/5$121

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to USA 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 6, 2026.
Use the filters below to find and compare flights from Ontario to the United States that are best for you.

Fly from

Ontario

Fly to

USA

Route

Depart

Return

Price

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 1/28

4:03 pm-6:54 pm

Nonstop2h 51m

Seattle/Tacoma Intl

Wed 2/4

6:00 pm-8:36 pm

Nonstop2h 36m

$119

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 1/28

5:55 am-12:05 pm

1 stop6h 10m

Seattle/Tacoma Intl

Wed 1/28

1:20 pm-9:05 pm

1 stop7h 45m

$121

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Sat 3/21

5:53 pm-8:50 pm

Nonstop2h 57m

Seattle/Tacoma Intl

Sat 3/28

5:30 pm-10:48 pm

1 stop5h 18m

$139

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Mon 3/2

6:14 am-9:09 am

Nonstop2h 55m

Seattle/Tacoma Intl

Mon 3/9

8:56 pm-11:32 pm

Nonstop2h 36m

$139

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 3/20

5:09 pm-12:03 am

1 stop6h 54m

Seattle/Tacoma Intl

Mon 3/23

2:30 pm-5:13 pm

Nonstop2h 43m

$139

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Mon 1/26

6:00 am-8:54 am

Nonstop2h 54m

Seattle/Tacoma Intl

Sun 2/8

9:20 pm-11:56 pm

Nonstop2h 36m

$139

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Mon 3/2

11:00 am-5:40 pm

1 stop6h 40m

Seattle/Tacoma Intl

Mon 3/9

5:00 am-10:35 am

1 stop5h 35m

$141

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 2/12

3:40 pm-12:10 am

1 stop8h 30m

Seattle/Tacoma Intl

Sun 2/15

7:55 am-12:15 pm

1 stop4h 20m

$146

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 2/3

3:20 pm-11:05 pm

1 stop7h 45m

Seattle/Tacoma Intl

Tue 2/10

2:05 pm-9:45 pm

1 stop7h 40m

$151

OntarioPhoenix

ONT - PHX

ONTPHX

Ontario

Mon 1/26

3:22 pm-8:07 pm

1 stop3h 45m

Phoenix Sky Harbor Intl

Thu 1/29

4:52 pm-7:53 pm

1 stop4h 01m

$157

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/6

Showing 1-10 of 60 results
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Best time to book a flight from Ontario to USA

Have a flexible travel schedule? Discover the best time to fly to USA 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.

Cheapflights Insights

Everything you need to know about your flight from Ontario to the United States

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

Currently, January is the cheapest month in which you can book a flight from Ontario to USA (average of $18). Flying from Ontario to USA in July is currently the most expensive (average of $49). 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 US?

Find hourly flight availability from Ontario to USA. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated January 6, 2026.

A simple way to save on the total cost of your ticket is to fly from Ontario to USA in the afternoon. If you’re flexible enough to do this you can expect to save up to 28% on your trip compared to booking a flight in the morning.

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

Use this chart to determine the cheapest time to fly round-trip from Ontario to USA. Price data was last updated on January 3, 2026.

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

How often are flights from Ontario to the United States delayed?

About 12% of weekly flights between Ontario and United States have experienced delays in the past year, with the average delay time being 125 minutes.

What is the most punctual flight time for Ontario to the United States flights?

Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the evening tend to experience delays more often.

What day of the week experiences the fewest flight delays on this route?

Saturday tends to have the lowest number of delays on this route, whereas Thursday has historically faced a higher average of delays compared to other days of the week.

Which airline has the best punctuality record on Ontario to the United States flights?

Over the last year, Delta have had the lowest number of delays on this route, with just 4% of flights being delayed.

Reviews of airlines servicing USA

Get insights into the airlines that provide service to USA. 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 USA. Reviews last updated January 6, 2026.
Read reviews from past customers who have flown Southwest, Delta, and United Airlines from Ontario to the United States. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,249 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Southwest
8.0
Very good
4,249 reviews
Southwest
8.0
Very good
4,249 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Delta
7.9
Good
8,022 reviews
Southwest
8.0
Very good
4,249 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
United Airlines
7.4
Good
9,138 reviews
Southwest
8.0
Very good
4,249 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
American Airlines
7.2
Good
11,088 reviews
Southwest
8.0
Very good
4,249 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Frontier
5.7
Fair
3,063 reviews
Southwest
8.0
Very good
4,249 reviews

Boarding

8.1

Entertainment

7.5

Comfort

8.0

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Related info for your journey

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

  • What airport do you fly from for flights from Ontario to United States?

    Ontario (ONT) is the airport you will fly out of if you book a flight from Ontario to United States. It is only a 3.1 mi journey to Ontario (ONT) from Ontario’s city center.

  • How long is the flight from Ontario to USA?

    Departing from Ontario to USA will take you 2h 51m. The distance from Ontario to USA is about 956 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines to fly from Ontario to USA one-way?

    $19 is the cheapest one-way deal found within the past few days, from Frontier. You may also be able to find cheap deals on Spirit Airlines and Alaska Airlines, with prices starting from $24 and $29, respectively.

  • What are the most popular routes from Ontario to USA?

    While some choose either Ontario - Seattle/Tacoma Intl or Ontario - Dallas/Fort Worth, Ontario - San Francisco is the most popular route from Ontario to USA.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Ontario to USA 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 USA?

    Currently, January is the cheapest month in which you can book a flight from Ontario to USA (average of $18). Flying from Ontario to USA in July is currently the most expensive (average of $49). 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.

See more FAQs

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Alternative routes for Ontario to USA

See prices for flight routes from nearby airports that may be better suited for you.
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Top 8 airlines flying from Ontario to USA

Discover the top 8 airlines that operate flights from Ontario to USA. 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 2,558,603 searches. Data last updated January 6, 2026.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$27Average$152FlexibilityNo cancel feeOn-time65%
FrontierCheapest$36Average$184FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$59Average$385FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$67Average$270FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$97Average$370FlexibilityNo cancel feeOn-time63%
DeltaCheapest$178Average$379FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$190Average$426FlexibilityNo cancel feeOn-time71%
JetBlueCheapest$223Average$331FlexibilityNo cancel feeOn-time62%

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