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$39+ 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 5/29. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LAX
Apr 1 — Apr 81
Tue 4/1
Tue 4/8
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 March 27, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$57
(United Airlines)

One-way from

$39
(United Airlines)

Popular in

June

Cheapest in

January

Average price

$367

Good round-trip deal

$93 or less

Good one-way deal

$50 or less
Provider with most accurate pricing for Los Angeles-New York (NYC) flight deals.
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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 ($49 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 March 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 March 27, 2025.

This United Airlines deal was found by Cheapflights users on 3/26. 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.
Fri 5/26:00 amONT - SFO
Nonstop1h 27mUnited Airlines
Sun 5/410:54 amSFO - ONT
Nonstop1h 30mUnited Airlines
Deal found 3/26$57
This Kiwi.com deal was found by Cheapflights users on 3/26. 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.
Thu 5/299:41 pmONT - SFO
Nonstop1h 30mFrontier
Sun 6/110:11 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 3/26$79
This Frontier deal was found by Cheapflights users on 3/25. 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.
Tue 4/19:39 pmONT - LAS
Nonstop1h 14mFrontier
Tue 4/87:45 pmLAS - ONT
Nonstop1h 04mFrontier
Deal found 3/25$80
This Southwest deal was found by Cheapflights users on 3/26. 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 5/97:35 pmONT - LAS
Nonstop1h 05mSouthwest
Sun 5/117:30 amLAS - ONT
Nonstop1h 00mSouthwest
Deal found 3/26$97
This Cheapflightsfares deal was found by Cheapflights users on 3/26. 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.
Mon 4/216:03 pmONT - DFW
Nonstop3h 03mFrontier
Thu 4/246:30 amDFW - ONT
Nonstop3h 24mFrontier
Deal found 3/26$98
This Cheapflightsfares deal was found by Cheapflights users on 3/26. 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 4/254:29 pmONT - SEA
Nonstop2h 54mFrontier
Sun 5/46:50 pmSEA - ONT
Nonstop2h 35mFrontier
Deal found 3/26$108
This Kiwi.com deal was found by Cheapflights users on 3/25. 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.
Wed 4/164:04 pmONT - IAH
Nonstop3h 02mFrontier
Sat 4/1911:59 amIAH - ONT
Nonstop3h 33mFrontier
Deal found 3/25$133
This Expedia deal was found by Cheapflights users on 3/26. 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 5/14:29 pmONT - SEA
Nonstop3h 03mMultiple Airlines
Wed 5/78:13 amSEA - ONT
Nonstop2h 38mMultiple Airlines
Deal found 3/26$149
This Southwest deal was found by Cheapflights users on 3/26. 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.
Sat 3/295:45 pmONT - SFO
1 stop7h 05mSouthwest
Wed 4/95:15 amSFO - ONT
1 stop5h 20mSouthwest
Deal found 3/26$164
This Expedia deal was found by Cheapflights users on 3/26. 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.
Mon 5/192:06 pmONT - IAH
Nonstop3h 31mMultiple Airlines
Sat 5/245:54 pmIAH - ONT
1 stop8h 03mMultiple Airlines
Deal found 3/26$175
This Delta deal was found by Cheapflights users on 3/26. 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.
Wed 5/142:55 pmONT - SEA
Nonstop3h 00mDelta
Tue 5/207:55 pmSEA - ONT
Nonstop2h 40mDelta
Deal found 3/26$177
This Southwest deal was found by Cheapflights users on 3/26. 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.
Wed 5/73:10 pmONT - HOU
1 stop6h 15mSouthwest
Fri 5/98:35 amHOU - ONT
Nonstop3h 30mSouthwest
Deal found 3/26$187

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 March 27, 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

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 5/2

6:00 am-7:27 am

Nonstop1h 27m

San Francisco

Sun 5/4

10:54 am-12:24 pm

Nonstop1h 30m

$57

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 5/29

9:41 pm-11:11 pm

Nonstop1h 30m

San Francisco

Sun 6/1

10:11 pm-11:39 pm

Nonstop1h 28m

$79

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Sat 4/12

10:02 pm-11:13 pm

Nonstop1h 11m

Las Vegas Harry Reid Intl

Tue 4/15

7:45 pm-8:49 pm

Nonstop1h 04m

$80

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Fri 5/9

9:05 pm-10:10 pm

Nonstop1h 05m

Las Vegas Harry Reid Intl

Sun 5/11

7:30 am-8:30 am

Nonstop1h 00m

$97

OntarioDallas

ONT - DFW

ONTDFW

Ontario

Mon 4/21

6:03 pm-11:06 pm

Nonstop3h 03m

Dallas/Fort Worth

Thu 4/24

6:30 am-7:54 am

Nonstop3h 24m

$98

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 4/25

4:29 pm-7:23 pm

Nonstop2h 54m

Seattle/Tacoma Intl

Sun 5/4

6:50 pm-9:25 pm

Nonstop2h 35m

$108

OntarioHouston

ONT - IAH

ONTIAH

Ontario

Wed 4/16

4:04 pm-9:06 pm

Nonstop3h 02m

Houston George Bush Intcntl

Sat 4/19

11:59 am-1:32 pm

Nonstop3h 33m

$133

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 5/1

4:29 pm-7:32 pm

Nonstop3h 03m

Seattle/Tacoma Intl

Wed 5/7

8:13 am-10:51 am

Nonstop2h 38m

$149

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 4/8

4:30 pm-10:55 pm

1 stop6h 25m

San Francisco

Thu 4/10

5:40 am-9:50 am

1 stop4h 10m

$154

OntarioHouston

ONT - IAH

ONTIAH

Ontario

Mon 5/19

2:06 pm-7:37 pm

Nonstop3h 31m

Houston George Bush Intcntl

Sat 5/24

5:54 pm-11:57 pm

1 stop8h 03m

$175

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/27

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 $246). Flying from Ontario to USA in March is currently the most expensive (average of $330). 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 March 27, 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 March 27, 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
4,273 reviews

Food

7.1

Boarding

8.2

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.
Southwest
8.1
Very good
4,273 reviews
Southwest
8.1
Very good
4,273 reviews

Food

7.1

Boarding

8.2

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.
Alaska Airlines
8.0
Very good
9,792 reviews
Southwest
8.1
Very good
4,273 reviews

Food

7.1

Boarding

8.2

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.
Delta
8.0
Very good
7,895 reviews
Southwest
8.1
Very good
4,273 reviews

Food

7.1

Boarding

8.2

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.
Hawaiian Airlines
7.9
Good
2,334 reviews
Southwest
8.1
Very good
4,273 reviews

Food

7.1

Boarding

8.2

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.
United Airlines
7.4
Good
8,603 reviews
Southwest
8.1
Very good
4,273 reviews

Food

7.1

Boarding

8.2

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.

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 United Airlines. You may also be able to find cheap deals on Frontier and Southwest, with prices starting from $40 and $59, respectively.

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

    While some choose either Ontario - Seattle/Tacoma Intl or Ontario - Honolulu, Ontario - Newark 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 $330). 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 10 airlines flying from Ontario to USA

Discover the top 10 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 March 27, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$25Average$177FlexibilityNo cancel feeOn-time65%
FrontierCheapest$36Average$167FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$67Average$306FlexibilityNo cancel feeOn-time75%
DeltaCheapest$68Average$355FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$76Average$398FlexibilityNo cancel feeOn-time69%
Breeze AirwaysCheapest$78Average$136FlexibilityNo cancel feeOn-timeN/A
Hawaiian AirlinesCheapest$88Average$240FlexibilityNo cancel feeOn-time85%
SouthwestCheapest$97Average$364FlexibilityNo cancel feeOn-time63%
JetBlueCheapest$97Average$369FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$202Average$433FlexibilityNo cancel feeOn-time71%
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