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$30+ 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 2/5. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LAX
Dec 10 — Dec 171
Wed 12/10
Wed 12/17
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 November 10, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$57
(Super.com)

One-way from

$30
(Kiwi.com)

Popular in

December

Cheapest in

January

Average price

$382

Good round-trip deal

$119 or less

Good one-way deal

$78 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. 7% potential increase in price ($26 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($8 potential savings vs. average RT price).
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Average for round-trip flights in November 2025
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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 November 10, 2025.

This CheapOair deal was found by Cheapflights users on 11/9. 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 12/36:15 amONT - LAS
Nonstop1h 07mFrontier
Wed 12/108:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/9$58
This Mytrip deal was found by Cheapflights users on 11/8. 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.
Wed 12/36:15 amONT - LAS
Nonstop1h 07mFrontier
Wed 12/38:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/8$59
This Super.com deal was found by Cheapflights users on 11/8. 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.
Wed 12/106:15 amONT - LAS
Nonstop1h 07mFrontier
Thu 12/118:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/8$60
This Kiwi.com deal was found by Cheapflights users on 11/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/66:15 amONT - LAS
Nonstop1h 07mFrontier
Sat 12/68:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/9$61
This Priceline deal was found by Cheapflights users on 11/9. 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.
Mon 12/86:15 amONT - LAS
Nonstop1h 07mFrontier
Sat 12/138:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/9$62
This Frontier deal was found by Cheapflights users on 11/8. 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.
Sat 12/136:15 amONT - LAS
Nonstop1h 07mFrontier
Mon 12/1512:56 pmLAS - ONT
Nonstop1h 08mFrontier
Deal found 11/8$63
This Super.com deal was found by Cheapflights users on 11/9. 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.
Wed 11/266:30 amONT - LAS
Nonstop1h 10mFrontier
Wed 12/38:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/9$66
This Super.com deal was found by Cheapflights users on 11/7. 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.
Mon 12/15:06 pmONT - LAS
Nonstop1h 09mFrontier
Wed 12/38:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/7$67
This Super.com deal was found by Cheapflights users on 11/10. 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.
Sun 11/306:30 amONT - LAS
Nonstop1h 10mFrontier
Thu 12/184:13 pmLAS - ONT
Nonstop1h 09mFrontier
Deal found 11/10$68
This Frontier deal was found by Cheapflights users on 11/8. 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.
Mon 12/15:06 pmONT - LAS
Nonstop1h 09mFrontier
Sat 12/68:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/8$69
This CheapOair deal was found by Cheapflights users on 11/9. 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.
Sun 12/75:18 pmONT - LAS
Nonstop1h 09mFrontier
Wed 12/108:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/9$71
This Super.com deal was found by Cheapflights users on 11/10. 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 12/46:15 amONT - LAS
Nonstop1h 07mFrontier
Fri 12/58:13 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 11/10$72

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 November 10, 2025.
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

OntarioDenver

ONT - DEN

ONTDEN

Ontario

Tue 1/13

1:24 pm-4:43 pm

Nonstop2h 19m

Denver Intl

Sat 1/17

11:23 am-12:47 pm

Nonstop2h 24m

$117

OntarioDenver

ONT - DEN

ONTDEN

Ontario

Fri 1/30

2:25 pm-5:35 pm

Nonstop2h 10m

Denver Intl

Sun 2/1

8:50 pm-10:20 pm

Nonstop2h 30m

$117

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 12/17

5:49 pm-8:49 pm

Nonstop3h 00m

Seattle/Tacoma Intl

Tue 1/6

11:25 am-4:13 pm

1 stop4h 48m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 12/16

4:49 pm-11:25 pm

1 stop6h 36m

Seattle/Tacoma Intl

Thu 1/8

11:15 am-1:56 pm

Nonstop2h 41m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 12/4

4:49 pm-12:21 am

1 stop7h 32m

Seattle/Tacoma Intl

Tue 12/9

2:19 pm-5:07 pm

Nonstop2h 48m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Sun 12/14

6:40 am-9:45 am

Nonstop3h 05m

Seattle/Tacoma Intl

Tue 1/6

5:25 am-12:16 pm

1 stop6h 51m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 1/23

3:30 pm-6:35 pm

Nonstop3h 05m

Seattle/Tacoma Intl

Mon 1/26

7:00 pm-11:58 pm

1 stop4h 58m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 12/11

5:49 pm-8:49 pm

Nonstop3h 00m

Seattle/Tacoma Intl

Mon 12/15

7:11 pm-11:58 pm

1 stop4h 47m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 12/18

5:49 pm-8:49 pm

Nonstop3h 00m

Seattle/Tacoma Intl

Sat 1/17

5:25 am-12:16 pm

1 stop6h 51m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Sat 12/6

6:40 am-9:45 am

Nonstop3h 05m

Seattle/Tacoma Intl

Mon 12/8

7:11 pm-11:58 pm

1 stop4h 47m

$130

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/8

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, December is the cheapest month in which you can book a flight from Ontario to USA (average of $17). 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 November 10, 2025.

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 31% 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 November 2, 2025.

Travelers seeking maximum savings on their Ontario to USA flight should consider departing on Sunday 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.

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 November 10, 2025.
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
4,235 reviews

Entertainment

7.5

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Southwest
8.0
Very good
4,235 reviews
Southwest
8.0
Very good
4,235 reviews

Entertainment

7.5

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Delta
7.9
Good
8,007 reviews
Southwest
8.0
Very good
4,235 reviews

Entertainment

7.5

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
United Airlines
7.4
Good
9,012 reviews
Southwest
8.0
Very good
4,235 reviews

Entertainment

7.5

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
American Airlines
7.2
Good
11,045 reviews
Southwest
8.0
Very good
4,235 reviews

Entertainment

7.5

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Frontier
5.8
Fair
3,113 reviews
Southwest
8.0
Very good
4,235 reviews

Entertainment

7.5

Crew

8.6

Food

7.0

Comfort

8.0

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.

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 10m. The distance from Ontario to USA is about 817 mi. Generally, flights for this route are nonstop.

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

    $66 is the cheapest one-way deal found within the past few days, from Frontier. You may also be able to find cheap deals on Southwest and United Airlines, with prices starting from $69 and $69, respectively.

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

    While some choose either Ontario - San Francisco or Ontario - Dallas/Fort Worth, Ontario - Seattle/Tacoma Intl 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, December is the cheapest month in which you can book a flight from Ontario to USA (average of $17). 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 November 10, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$24Average$168FlexibilityNo cancel feeOn-time65%
FrontierCheapest$36Average$179FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$58Average$385FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$67Average$319FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$97Average$376FlexibilityNo cancel feeOn-time63%
DeltaCheapest$178Average$387FlexibilityNo cancel feeOn-timeN/A
JetBlueCheapest$237Average$330FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$242Average$429FlexibilityNo cancel feeOn-time71%

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