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$34+ 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 3/22. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LAX
Feb 28 — Mar 71
Fri 2/28
Fri 3/7
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 February 23, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$41
(Kiwi.com)

One-way from

$34
(Cheapflightsfares)

Popular in

June

Cheapest in

January

Average price

$312

Good round-trip deal

$72 or less

Good one-way deal

$44 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. 12% potential increase in price ($51 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($8 potential savings vs. average RT price).
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Average for round-trip flights in February 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 February 23, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 2/22. 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.
Thu 3/68:26 amONT - SFO
Nonstop1h 36mFrontier
Sun 3/168:16 amSFO - ONT
Nonstop1h 28mFrontier
Deal found 2/22$42
This Cheapflightsfares deal was found by Cheapflights users on 2/20. 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.
Sat 4/1910:02 pmONT - LAS
Nonstop1h 11mFrontier
Sun 4/206:20 amLAS - ONT
Nonstop1h 05mFrontier
Deal found 2/20$43
This Frontier deal was found by Cheapflights users on 2/22. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/1612:59 amONT - DEN
Nonstop2h 19mFrontier
Tue 6/249:05 amDEN - ONT
Nonstop2h 23mFrontier
Deal found 2/22$68
This Cheapflightsfares deal was found by Cheapflights users on 2/21. 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 3/2110:21 amONT - SEA
Nonstop2h 51mFrontier
Mon 3/2412:52 pmSEA - ONT
Nonstop2h 37mFrontier
Deal found 2/21$96
This Frontier deal was found by Cheapflights users on 2/22. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/108:29 amONT - DFW
Nonstop3h 14mFrontier
Sat 4/126:15 amDFW - ONT
Nonstop3h 24mFrontier
Deal found 2/22$97
This Alaska Airlines deal was found by Cheapflights users on 2/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/146:00 amONT - SEA
Nonstop2h 50mAlaska Airlines
Mon 3/249:23 pmSEA - ONT
Nonstop2h 36mAlaska Airlines
Deal found 2/21$97
This United Airlines deal was found by Cheapflights users on 2/22. 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.
Thu 2/276:00 amONT - SFO
Nonstop1h 29mUnited Airlines
Sat 3/15:00 pmSFO - ONT
Nonstop1h 31mUnited Airlines
Deal found 2/22$97
This Expedia deal was found by Cheapflights users on 2/21. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/1310:21 amONT - SEA
Nonstop2h 51mMultiple Airlines
Mon 3/178:25 amSEA - ONT
Nonstop2h 37mMultiple Airlines
Deal found 2/21$103
This Delta deal was found by Cheapflights users on 2/20. 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.
Fri 3/145:15 pmONT - SEA
1 stop6h 54mDelta
Mon 3/177:40 pmSEA - ONT
Nonstop2h 42mDelta
Deal found 2/20$107
This Southwest deal was found by Cheapflights users on 2/20. 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 4/17:55 pmONT - LAS
Nonstop1h 05mSouthwest
Wed 4/25:50 amLAS - ONT
1 stop3h 30mSouthwest
Deal found 2/20$117
This Trip.com deal was found by Cheapflights users on 2/21. 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.
Thu 3/206:00 amONT - SEA
Nonstop2h 50mHawaiian Airlines
Mon 3/249:23 pmSEA - ONT
Nonstop2h 36mHawaiian Airlines
Deal found 2/21$124
This Southwest deal was found by Cheapflights users on 2/21. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/25:35 amONT - DEN
Nonstop2h 10mSouthwest
Mon 5/58:10 amDEN - ONT
1 stop5h 25mSouthwest
Deal found 2/21$127

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 February 23, 2025.

Fly from

Ontario

Fly to

USA

Route

Depart

Return

Price

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 3/6

8:26 am-10:02 am

Nonstop1h 36m

San Francisco

Sun 3/16

8:16 am-9:44 am

Nonstop1h 28m

$41

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Sat 4/19

10:02 pm-11:13 pm

Nonstop1h 11m

Las Vegas Harry Reid Intl

Sun 4/20

6:20 am-7:25 am

Nonstop1h 05m

$43

OntarioDenver

ONT - DEN

ONTDEN

Ontario

Tue 3/4

12:59 am-4:16 am

Nonstop2h 17m

Denver Intl

Mon 3/10

10:37 pm-12:09 am

Nonstop2h 32m

$73

OntarioDallas

ONT - DFW

ONTDFW

Ontario

Tue 4/22

2:27 pm-7:29 pm

Nonstop3h 02m

Dallas/Fort Worth

Wed 4/23

12:13 pm-1:37 pm

Nonstop3h 24m

$96

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 3/21

10:21 am-1:12 pm

Nonstop2h 51m

Seattle/Tacoma Intl

Mon 3/24

12:52 pm-3:29 pm

Nonstop2h 37m

$96

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 3/14

6:00 am-8:50 am

Nonstop2h 50m

Seattle/Tacoma Intl

Mon 3/24

9:23 pm-11:59 pm

Nonstop2h 36m

$97

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 3/13

10:21 am-1:12 pm

Nonstop2h 51m

Seattle/Tacoma Intl

Mon 3/17

8:25 am-11:02 am

Nonstop2h 37m

$103

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 3/14

5:15 pm-12:09 am

1 stop6h 54m

Seattle/Tacoma Intl

Mon 3/17

7:40 pm-10:22 pm

Nonstop2h 42m

$107

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 4/15

1:20 pm-3:04 pm

Nonstop1h 44m

San Francisco

Tue 4/15

6:55 pm-8:21 pm

Nonstop1h 26m

$113

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Tue 4/1

7:55 pm-9:00 pm

Nonstop1h 05m

Las Vegas Harry Reid Intl

Wed 4/2

5:50 am-9:20 am

1 stop3h 30m

$117

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/21

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 February 23, 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 February 23, 2025.
Peruse reviews from past customers who have flown with Southwest, Alaska Airlines and Delta 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
4,395 reviews

Comfort

8.1

Entertainment

7.6

Overall

8.1

Crew

8.7

Boarding

8.2

Food

7.1

Reviews

1 / 20

2.0
Mediocre

Steven,Feb 2025

BZN - DEN

Bozeman Airport knows how to deal with snow. I saw many airlines leave with only small delays due to the foot of snow. Our plane was 4 hours delayed. I missed my connection in Denver with a 3.5 hour layover. Because of that, the best you Southwest could do was make me wait more hours, them send me to Chicago Midway, where I had to wait overnight, for 7 more hours until a flight to RSW was available. Nobody at Southwest told me that Midway shuts down after 8pm. Everything was closed. I had no idea. You just dumped me there. I am a 65 year old man and you dumped me in Midway without even a couch to lie on. I was awake 21 hours because of this. No, it was not an act of God. Other airlines were moving passengers out. It was incompetence Shame on you.

Southwest
8.1
Very good
4,395 reviews
Southwest
8.1
Very good
4,395 reviews

Comfort

8.1

Entertainment

7.6

Overall

8.1

Crew

8.7

Boarding

8.2

Food

7.1

Reviews

1 / 20

2.0
Mediocre

Steven,Feb 2025

BZN - DEN

Bozeman Airport knows how to deal with snow. I saw many airlines leave with only small delays due to the foot of snow. Our plane was 4 hours delayed. I missed my connection in Denver with a 3.5 hour layover. Because of that, the best you Southwest could do was make me wait more hours, them send me to Chicago Midway, where I had to wait overnight, for 7 more hours until a flight to RSW was available. Nobody at Southwest told me that Midway shuts down after 8pm. Everything was closed. I had no idea. You just dumped me there. I am a 65 year old man and you dumped me in Midway without even a couch to lie on. I was awake 21 hours because of this. No, it was not an act of God. Other airlines were moving passengers out. It was incompetence Shame on you.

Alaska Airlines
8.0
Very good
9,706 reviews
Southwest
8.1
Very good
4,395 reviews

Comfort

8.1

Entertainment

7.6

Overall

8.1

Crew

8.7

Boarding

8.2

Food

7.1

Reviews

1 / 20

2.0
Mediocre

Steven,Feb 2025

BZN - DEN

Bozeman Airport knows how to deal with snow. I saw many airlines leave with only small delays due to the foot of snow. Our plane was 4 hours delayed. I missed my connection in Denver with a 3.5 hour layover. Because of that, the best you Southwest could do was make me wait more hours, them send me to Chicago Midway, where I had to wait overnight, for 7 more hours until a flight to RSW was available. Nobody at Southwest told me that Midway shuts down after 8pm. Everything was closed. I had no idea. You just dumped me there. I am a 65 year old man and you dumped me in Midway without even a couch to lie on. I was awake 21 hours because of this. No, it was not an act of God. Other airlines were moving passengers out. It was incompetence Shame on you.

Delta
8.0
Very good
8,203 reviews
Southwest
8.1
Very good
4,395 reviews

Comfort

8.1

Entertainment

7.6

Overall

8.1

Crew

8.7

Boarding

8.2

Food

7.1

Reviews

1 / 20

2.0
Mediocre

Steven,Feb 2025

BZN - DEN

Bozeman Airport knows how to deal with snow. I saw many airlines leave with only small delays due to the foot of snow. Our plane was 4 hours delayed. I missed my connection in Denver with a 3.5 hour layover. Because of that, the best you Southwest could do was make me wait more hours, them send me to Chicago Midway, where I had to wait overnight, for 7 more hours until a flight to RSW was available. Nobody at Southwest told me that Midway shuts down after 8pm. Everything was closed. I had no idea. You just dumped me there. I am a 65 year old man and you dumped me in Midway without even a couch to lie on. I was awake 21 hours because of this. No, it was not an act of God. Other airlines were moving passengers out. It was incompetence Shame on you.

Hawaiian Airlines
7.9
Good
2,314 reviews
Southwest
8.1
Very good
4,395 reviews

Comfort

8.1

Entertainment

7.6

Overall

8.1

Crew

8.7

Boarding

8.2

Food

7.1

Reviews

1 / 20

2.0
Mediocre

Steven,Feb 2025

BZN - DEN

Bozeman Airport knows how to deal with snow. I saw many airlines leave with only small delays due to the foot of snow. Our plane was 4 hours delayed. I missed my connection in Denver with a 3.5 hour layover. Because of that, the best you Southwest could do was make me wait more hours, them send me to Chicago Midway, where I had to wait overnight, for 7 more hours until a flight to RSW was available. Nobody at Southwest told me that Midway shuts down after 8pm. Everything was closed. I had no idea. You just dumped me there. I am a 65 year old man and you dumped me in Midway without even a couch to lie on. I was awake 21 hours because of this. No, it was not an act of God. Other airlines were moving passengers out. It was incompetence Shame on you.

JetBlue
7.4
Good
3,068 reviews
Southwest
8.1
Very good
4,395 reviews

Comfort

8.1

Entertainment

7.6

Overall

8.1

Crew

8.7

Boarding

8.2

Food

7.1

Reviews

1 / 20

2.0
Mediocre

Steven,Feb 2025

BZN - DEN

Bozeman Airport knows how to deal with snow. I saw many airlines leave with only small delays due to the foot of snow. Our plane was 4 hours delayed. I missed my connection in Denver with a 3.5 hour layover. Because of that, the best you Southwest could do was make me wait more hours, them send me to Chicago Midway, where I had to wait overnight, for 7 more hours until a flight to RSW was available. Nobody at Southwest told me that Midway shuts down after 8pm. Everything was closed. I had no idea. You just dumped me there. I am a 65 year old man and you dumped me in Midway without even a couch to lie on. I was awake 21 hours because of this. No, it was not an act of God. Other airlines were moving passengers out. It was incompetence Shame on you.

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?

    $34 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 Delta, with prices starting from $49 and $59, respectively.

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

    While some choose either Ontario - Honolulu 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 February 23, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$29Average$174FlexibilityNo cancel feeOn-time65%
FrontierCheapest$36Average$168FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$67Average$309FlexibilityNo cancel feeOn-time75%
DeltaCheapest$68Average$354FlexibilityNo cancel feeOn-timeN/A
Breeze AirwaysCheapest$78Average$130FlexibilityNo cancel feeOn-timeN/A
JetBlueCheapest$78Average$356FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$97Average$402FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$152Average$379FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$199Average$442FlexibilityNo cancel feeOn-time71%
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