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Ontario

$38+ Cheap flights from California to Ontario (ONT)

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 5/16. Fares are subject to change and may not be available on all flights or dates of travel.
LAX — ONT
Apr 29 — May 61
Tue 4/29
Tue 5/6
1 adult, Economy
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Cheap flight deals from California to Ontario

Keep the following information in mind while searching for California to Ontario flight deals. Data was last updated April 24, 2025.

Round-trip from

$46
(Cheapflightsfares)

One-way from

$38
(Cheapflightsfares)

Good round-trip deal

$77 or less

Good one-way deal

$39 or less
From California to Ontario
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One-way flight from California to Ontario
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Price to beat on a round-trip flight from California to Ontario.
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Price to beat on a one-way flight from California to Ontario.
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Find flight deals from California to Ontario

Cheapest flights from California to Ontario
Explore the most affordable flight options available from California to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 24, 2025.

This Frontier deal was found by Cheapflights users on 4/22. 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.
Fri 5/166:20 amLAS - ONT
Nonstop1h 04mFrontier
Sat 5/171:15 pmONT - LAS
Nonstop1h 11mFrontier
Deal found 4/22$53
This Frontier deal was found by Cheapflights users on 4/24. 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 5/88:34 amSFO - ONT
Nonstop1h 28mFrontier
Sun 5/118:24 amONT - SFO
Nonstop1h 38mFrontier
Deal found 4/24$58
This Southwest deal was found by Cheapflights users on 4/23. 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 5/2210:00 amSJC - ONT
Nonstop1h 15mSouthwest
Tue 6/36:10 amONT - SJC
Nonstop1h 15mSouthwest
Deal found 4/23$77
This Southwest deal was found by Cheapflights users on 4/23. 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 5/218:30 pmOAK - ONT
Nonstop1h 20mSouthwest
Wed 5/287:50 pmONT - OAK
Nonstop1h 20mSouthwest
Deal found 4/23$77
This United Airlines deal was found by Cheapflights users on 4/23. 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.
Wed 5/710:54 amSFO - ONT
Nonstop1h 30mUnited Airlines
Wed 5/73:10 pmONT - SFO
Nonstop1h 43mUnited Airlines
Deal found 4/23$112
This Southwest deal was found by Cheapflights users on 4/24. 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 5/65:15 amSFO - ONT
1 stop7h 05mSouthwest
Thu 5/87:35 pmONT - SFO
1 stop3h 50mSouthwest
Deal found 4/24$154
This Frontier deal was found by Cheapflights users on 4/23. 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 5/1412:06 pmRNO - ONT
1 stop11h 02mFrontier
Tue 5/2012:59 amONT - RNO
1 stop10h 17mFrontier
Deal found 4/23$160
This Frontier deal was found by Cheapflights users on 4/23. 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 5/812:04 pmSJC - ONT
1 stop11h 55mFrontier
Wed 5/1411:58 pmONT - SJC
1 stop11h 06mFrontier
Deal found 4/23$170
This Southwest deal was found by Cheapflights users on 4/21. 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 5/167:25 pmLAS - ONT
1 stop3h 35mSouthwest
Mon 5/191:55 pmONT - LAS
1 stop3h 55mSouthwest
Deal found 4/21$173
This Frontier deal was found by Cheapflights users on 4/23. 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 5/81:18 pmSMF - ONT
1 stop4h 27mFrontier
Sun 5/1112:59 amONT - SMF
1 stop10h 07mFrontier
Deal found 4/23$180
This Southwest deal was found by Cheapflights users on 4/23. 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 5/213:55 pmSMF - ONT
1 stop6h 35mSouthwest
Wed 5/2812:55 pmONT - SMF
Nonstop1h 25mSouthwest
Deal found 4/23$185
This American Airlines deal was found by Cheapflights users on 4/23. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/269:15 amSFO - ONT
1 stop6h 44mAmerican Airlines
Sat 4/267:25 pmONT - SFO
1 stop4h 33mAmerican Airlines
Deal found 4/23$193

Cheapflights Fare Finder

Customize your flight search to find flights from California to Ontario 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 April 24, 2025.
Use the filters below to find and compare flights from California to Ontario that are best for you.

Fly from

California

Fly to

Ontario

Route

Depart

Return

Price

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Fri 5/16

6:20 am-7:24 am

Nonstop1h 04m

Ontario

Tue 5/20

1:08 pm-2:19 pm

Nonstop1h 11m

$52

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 5/8

8:34 am-10:02 am

Nonstop1h 28m

Ontario

Sun 5/11

8:24 am-10:02 am

Nonstop1h 38m

$58

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 5/22

10:00 am-11:15 am

Nonstop1h 15m

Ontario

Tue 6/3

6:10 am-7:25 am

Nonstop1h 15m

$77

OaklandOntario

OAK - ONT

OAKONT

Oakland

Wed 5/21

8:30 pm-9:50 pm

Nonstop1h 20m

Ontario

Wed 5/28

7:50 pm-9:10 pm

Nonstop1h 20m

$77

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 5/7

10:54 am-12:24 pm

Nonstop1h 30m

Ontario

Wed 5/7

3:10 pm-4:53 pm

Nonstop1h 43m

$112

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Tue 5/6

5:15 am-12:20 pm

1 stop7h 05m

Ontario

Thu 5/8

7:35 pm-11:25 pm

1 stop3h 50m

$154

RenoOntario

RNO - ONT

RNOONT

Reno

Wed 5/14

12:06 pm-11:08 pm

1 stop11h 02m

Ontario

Tue 5/20

12:59 am-11:16 am

1 stop10h 17m

$160

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 5/8

12:04 pm-11:59 pm

1 stop11h 55m

Ontario

Wed 5/14

11:58 pm-11:04 am

1 stop11h 06m

$170

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Fri 5/16

7:25 pm-11:00 pm

1 stop3h 35m

Ontario

Mon 5/19

1:55 pm-5:50 pm

1 stop3h 55m

$173

SacramentoOntario

SMF - ONT

SMFONT

Sacramento Intl

Thu 5/8

1:18 pm-5:45 pm

1 stop4h 27m

Ontario

Sun 5/11

12:59 am-11:06 am

1 stop10h 07m

$180

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/24

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

Have a flexible travel schedule? Discover the best time to fly to Ontario from California 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 California to Ontario

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

Currently, August is the cheapest month in which you can book a flight from California to Ontario (average of $246). Flying from California to Ontario in March is currently the most expensive (average of $328). 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 CA to ONT?

Find hourly flight availability from California to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 24, 2025.

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

Rainfall in Ontario by month

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

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

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

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated April 24, 2025.
To help decide which airline to fly from California to Ontario, see what other customers have to say about Alaska Airlines, Southwest and Delta. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,918 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Boarding

8.2

Entertainment

7.1

Overall

8.0

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
Alaska Airlines
8.0
Very good
9,918 reviews
Alaska Airlines
8.0
Very good
9,918 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Boarding

8.2

Entertainment

7.1

Overall

8.0

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
Southwest
8.0
Very good
4,287 reviews
Alaska Airlines
8.0
Very good
9,918 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Boarding

8.2

Entertainment

7.1

Overall

8.0

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
Delta
8.0
Very good
7,920 reviews
Alaska Airlines
8.0
Very good
9,918 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Boarding

8.2

Entertainment

7.1

Overall

8.0

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
Hawaiian Airlines
7.9
Good
2,393 reviews
Alaska Airlines
8.0
Very good
9,918 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Boarding

8.2

Entertainment

7.1

Overall

8.0

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
United Airlines
7.4
Good
8,685 reviews
Alaska Airlines
8.0
Very good
9,918 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Boarding

8.2

Entertainment

7.1

Overall

8.0

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >

Related info for your journey

Find useful and relevant information for your journey from California to Ontario. 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 into for flights to Ontario from California?

    Located just 3.1 mi from the city center, Ontario (ONT) is the airport most travelers will use when flying to Ontario from California.

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

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $38. Users have also found prices from $39 and $59 on Southwest and United Airlines, respectively.

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

    When deciding which route to take from California to Ontario consider San Francisco - Ontario, San Jose - Ontario or Oakland - Ontario as they are the most popular.

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

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

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

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

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

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

    Currently, August is the cheapest month in which you can book a flight from California to Ontario (average of $246). Flying from California to Ontario in March is currently the most expensive (average of $328). 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 California to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Top 6 airlines flying from California to Ontario

Discover the top 6 airlines that operate flights from California to Ontario. 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 April 24, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$29Average$99FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$32Average$107FlexibilityNo cancel feeOn-time65%
DeltaCheapest$45Average$173FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$59Average$332FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$74Average$307FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$147Average$278FlexibilityNo cancel feeOn-time63%

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