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$37+ 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 6/16. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LAX
Jan 27 — Feb 31
Mon 1/27
Mon 2/3
1 adult, Economy
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Cheap flight deals from Ontario to USA

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to USA (US0). 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 22, 2025.

Round-trip from

$38
(Frontier)

Good round-trip deal

$76 or less

Good one-way deal

$32 or less
From Ontario to USA
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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 22, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 1/22. 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.
Fri 3/1410:44 amONT - LAS
Nonstop1h 14mFrontier
Mon 3/176:20 amLAS - ONT
Nonstop1h 06mFrontier
Deal found 1/22$47
This Cheapflightsfares deal was found by Cheapflights users on 1/21. 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.
Fri 2/288:26 amONT - SFO
Nonstop1h 36mFrontier
Sun 3/28:06 amSFO - ONT
Nonstop1h 28mFrontier
Deal found 1/21$48
This United Airlines deal was found by Cheapflights users on 1/22. 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 3/47:40 pmONT - SFO
Nonstop1h 33mUnited Airlines
Wed 3/57:45 amSFO - ONT
Nonstop1h 30mUnited Airlines
Deal found 1/22$57
This Cheapflightsfares deal was found by Cheapflights users on 1/22. 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.
Fri 2/2111:25 amONT - SEA
Nonstop2h 51mFrontier
Sun 2/2312:52 pmSEA - ONT
Nonstop2h 37mFrontier
Deal found 1/22$106
This Kiwi.com deal was found by Cheapflights users on 1/22. 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.
Fri 2/2812:59 amONT - SLC
1 stop5h 59mFrontier
Tue 3/412:40 pmSLC - ONT
1 stop7h 18mFrontier
Deal found 1/22$108
This Trip.com deal was found by Cheapflights users on 1/21. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/2612:59 amONT - DFW
1 stop21h 06mFrontier
Tue 3/45:30 pmDFW - ONT
Nonstop3h 28mFrontier
Deal found 1/21$115
This Justfly.com deal was found by Cheapflights users on 1/22. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/57:45 amONT - HOU
1 stop7h 41mFrontier
Sat 2/153:43 pmHOU - ONT
1 stop19h 48mFrontier
Deal found 1/22$118
This Frontier deal was found by Cheapflights users on 1/21. 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 2/228:09 pmONT - MIA
1 stop11h 44mFrontier
Wed 3/58:00 amMIA - ONT
1 stop12h 58mFrontier
Deal found 1/21$130
This Travelocity deal was found by Cheapflights users on 1/22. 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 2/256:00 amONT - SEA
Nonstop2h 50mMultiple Airlines
Thu 2/2712:52 pmSEA - ONT
Nonstop2h 37mMultiple Airlines
Deal found 1/22$132
This Southwest deal was found by Cheapflights users on 1/22. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/275:20 amONT - LAS
1 stop3h 45mSouthwest
Thu 3/2712:30 pmLAS - ONT
Nonstop1h 05mSouthwest
Deal found 1/22$142
This Southwest deal was found by Cheapflights users on 1/22. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/2912:45 pmONT - SFO
2 stops9h 55mSouthwest
Thu 5/15:40 amSFO - ONT
1 stop4h 10mSouthwest
Deal found 1/22$142
This Alaska Airlines deal was found by Cheapflights users on 1/22. 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.
Wed 2/266:00 amONT - SEA
Nonstop2h 50mAlaska Airlines
Tue 3/48:25 amSEA - ONT
Nonstop2h 37mAlaska Airlines
Deal found 1/22$157

Find flights from Ontario to USA within your budget

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 22, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 2/28

8:26 am-10:02 am

Nonstop1h 36m

San Francisco

Mon 3/3

8:06 am-9:34 am

Nonstop1h 28m

$42

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Wed 2/19

2:43 pm-3:58 pm

Nonstop1h 15m

Las Vegas Harry Reid Intl

Wed 2/26

2:10 pm-3:19 pm

Nonstop1h 09m

$47

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 2/6

6:15 am-7:46 am

Nonstop1h 31m

San Francisco

Sat 2/8

8:25 am-9:51 am

Nonstop1h 26m

$57

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 2/21

11:25 am-2:16 pm

Nonstop2h 51m

Seattle/Tacoma Intl

Sun 2/23

12:52 pm-3:29 pm

Nonstop2h 37m

$106

OntarioSalt Lake City

ONT - SLC

ONTSLC

Ontario

Fri 2/28

12:59 am-7:58 am

1 stop5h 59m

Salt Lake City

Tue 3/4

12:40 pm-6:58 pm

1 stop7h 18m

$108

OntarioDallas

ONT - DFW

ONTDFW

Ontario

Wed 2/26

12:59 am-12:05 am

1 stop21h 06m

Dallas/Fort Worth

Tue 3/4

5:30 pm-6:58 pm

Nonstop3h 28m

$115

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Wed 2/5

7:45 am-5:26 pm

1 stop7h 41m

Houston Hobby

Sat 2/15

3:43 pm-9:31 am

1 stop19h 48m

$118

OntarioMiami

ONT - MIA

ONTMIA

Ontario

Sat 2/22

8:09 pm-10:53 am

1 stop11h 44m

Miami

Wed 3/5

8:00 am-5:58 pm

1 stop12h 58m

$130

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 2/25

6:00 am-8:50 am

Nonstop2h 50m

Seattle/Tacoma Intl

Thu 2/27

12:52 pm-3:29 pm

Nonstop2h 37m

$132

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 2/7

5:00 am-10:15 am

1 stop5h 15m

San Francisco

Sun 2/9

6:05 am-12:55 pm

1 stop6h 50m

$137

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/22

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.

Travel insights for flights from Ontario to USA

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

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 $246). Flying from Ontario to USA in March is currently the most expensive (average of $344). 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 22, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Ontario to USA as you normally would.

Rainfall in USA by month

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

In terms of precipitation, rainfall in USA ranges from 2.8 - 4.5 inches per month. July is typically the wettest month, when rainfall can reach 4.5 in. February is typically the driest time to visit USA when rainfall is around 2.8 in.

Temperature in USA by month

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

If weather is an important factor for your trip to USA, 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 77.0 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 33.8 F).

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 22, 2025.
Peruse reviews from past customers who have flown with Frontier, American Airlines and United Airlines from Ontario to USA to help guide your decision. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,654 reviews

Entertainment

7.7

Boarding

8.2

Food

7.2

Comfort

8.1

Crew

8.7

Overall

8.1

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

Southwest
8.1
Very good
4,654 reviews
Southwest
8.1
Very good
4,654 reviews

Entertainment

7.7

Boarding

8.2

Food

7.2

Comfort

8.1

Crew

8.7

Overall

8.1

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

Alaska Airlines
8.0
Very good
9,707 reviews
Southwest
8.1
Very good
4,654 reviews

Entertainment

7.7

Boarding

8.2

Food

7.2

Comfort

8.1

Crew

8.7

Overall

8.1

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

Delta
8.0
Very good
8,512 reviews
Southwest
8.1
Very good
4,654 reviews

Entertainment

7.7

Boarding

8.2

Food

7.2

Comfort

8.1

Crew

8.7

Overall

8.1

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

Hawaiian Airlines
7.9
Good
2,332 reviews
Southwest
8.1
Very good
4,654 reviews

Entertainment

7.7

Boarding

8.2

Food

7.2

Comfort

8.1

Crew

8.7

Overall

8.1

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

JetBlue
7.4
Good
3,191 reviews
Southwest
8.1
Very good
4,654 reviews

Entertainment

7.7

Boarding

8.2

Food

7.2

Comfort

8.1

Crew

8.7

Overall

8.1

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

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.

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

    $39 is the cheapest one-way deal found within the past few days, from Frontier. You may also be able to find cheap deals on United Airlines and Southwest, with prices starting from $59 and $69, respectively.

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

    While some choose either Ontario - Dallas/Fort Worth or Ontario - San Francisco, 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, January is the cheapest month in which you can book a flight from Ontario to USA (average of $246). Flying from Ontario to USA in March is currently the most expensive (average of $344). 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 9 airlines flying from Ontario to USA

Discover the top 9 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 22, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$31Average$168FlexibilityNo cancel feeOn-time65%
FrontierCheapest$38Average$170FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$38Average$281FlexibilityNo cancel feeOn-time75%
Breeze AirwaysCheapest$78Average$135FlexibilityNo cancel feeOn-timeN/A
JetBlueCheapest$78Average$344FlexibilityNo cancel feeOn-time62%
DeltaCheapest$85Average$353FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$117Average$408FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$176Average$388FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$177Average$418FlexibilityNo cancel feeOn-time71%
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