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$30+ 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 12/5. Fares are subject to change and may not be available on all flights or dates of travel.
LAX — ONT
Oct 15 — Oct 221
Wed 10/15
Wed 10/22
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 September 15, 2025.

Round-trip from

$62
(Cheapflightsfares)

One-way from

$30
(SmartFares)

Good round-trip deal

$96 or less

Good one-way deal

$58 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 September 15, 2025.

This Kiwi.com deal was found by Cheapflights users on 9/13. 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.
Sun 9/286:10 amLAS - ONT
Nonstop1h 07mFrontier
Sun 9/2810:28 pmONT - LAS
Nonstop1h 16mFrontier
Deal found 9/13$60
This Cheapflightsfares deal was found by Cheapflights users on 9/14. 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 10/310:27 amLAS - ONT
Nonstop1h 16mFrontier
Sun 10/510:28 pmONT - LAS
Nonstop1h 16mFrontier
Deal found 9/14$62
This Frontier deal was found by Cheapflights users on 9/15. 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 10/38:48 pmLAS - ONT
Nonstop1h 07mFrontier
Mon 10/66:00 amONT - LAS
Nonstop1h 11mFrontier
Deal found 9/15$63
This Cheapflightsfares deal was found by Cheapflights users on 9/14. 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 9/2510:22 amLAS - ONT
Nonstop1h 16mFrontier
Thu 10/29:16 amONT - LAS
Nonstop1h 08mFrontier
Deal found 9/14$65
This flugladen.de deal was found by Cheapflights users on 9/13. 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 flugladen.de is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/266:10 amLAS - ONT
Nonstop1h 07mFrontier
Sun 9/286:00 amONT - LAS
Nonstop1h 11mFrontier
Deal found 9/13$69
This Cheapflightsfares deal was found by Cheapflights users on 9/12. 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 9/2910:11 pmSFO - ONT
Nonstop1h 27mFrontier
Thu 10/29:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/12$72
This Frontier deal was found by Cheapflights users on 9/14. 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 10/38:48 pmLAS - ONT
Nonstop1h 07mFrontier
Fri 10/1010:47 pmONT - LAS
Nonstop1h 10mFrontier
Deal found 9/14$72
This Cheapflightsfares deal was found by Cheapflights users on 9/15. 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.
Tue 9/308:49 pmLAS - ONT
Nonstop1h 07mFrontier
Fri 10/310:28 pmONT - LAS
Nonstop1h 16mFrontier
Deal found 9/15$73
This Flightnetwork deal was found by Cheapflights users on 9/14. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/1510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 9/229:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/14$74
This Cheapflightsfares deal was found by Cheapflights users on 9/14. 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 9/2711:27 amLAS - ONT
Nonstop1h 16mFrontier
Wed 10/18:00 amONT - LAS
Nonstop1h 11mFrontier
Deal found 9/14$75
This United Airlines deal was found by Cheapflights users on 9/13. 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.
Mon 10/69:30 pmSFO - ONT
Nonstop1h 22mUnited Airlines
Sat 10/116:51 pmONT - SFO
Nonstop1h 19mUnited Airlines
Deal found 9/13$77
This Cheapflightsfares deal was found by Cheapflights users on 9/14. 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.
Sun 10/1210:38 pmSFO - ONT
Nonstop1h 29mFrontier
Sun 10/1910:40 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/14$78

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 September 15, 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 10/3

10:27 am-11:43 am

Nonstop1h 16m

Ontario

Mon 10/6

6:00 am-7:11 am

Nonstop1h 11m

$64

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 10/25

9:30 pm-10:52 pm

Nonstop1h 22m

Ontario

Wed 10/29

6:38 pm-8:02 pm

Nonstop1h 24m

$77

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Thu 10/9

7:40 am-8:45 am

Nonstop1h 05m

Ontario

Sun 10/12

9:05 pm-10:10 pm

Nonstop1h 05m

$77

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Fri 10/24

10:00 pm-11:00 pm

Nonstop1h 00m

Ontario

Mon 11/3

2:05 pm-5:50 pm

1 stop3h 45m

$87

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Tue 10/14

7:20 am-8:25 am

Nonstop1h 05m

Ontario

Tue 10/21

2:25 pm-6:45 pm

1 stop4h 20m

$87

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Wed 10/8

7:35 am-11:15 am

1 stop3h 40m

Ontario

Thu 10/9

9:35 pm-10:40 pm

Nonstop1h 05m

$87

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Wed 10/8

7:20 am-8:25 am

Nonstop1h 05m

Ontario

Wed 10/8

6:30 pm-10:05 pm

1 stop3h 35m

$87

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Tue 10/7

7:33 pm-8:42 pm

Nonstop1h 09m

Ontario

Thu 10/9

6:05 am-7:16 am

Nonstop1h 11m

$97

San JoseOntario

SJC - ONT

SJCONT

San Jose

Sat 10/25

11:30 am-12:45 pm

Nonstop1h 15m

Ontario

Sat 10/25

3:50 pm-5:05 pm

Nonstop1h 15m

$97

San JoseOntario

SJC - ONT

SJCONT

San Jose

Tue 10/21

11:35 am-12:55 pm

Nonstop1h 20m

Ontario

Sat 10/25

11:25 am-12:40 pm

Nonstop1h 15m

$97

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/15

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 September 15, 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.

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 September 15, 2025.
See what other customers who have flown with Southwest, Avelo Airlines, and United Airlines from California to Ontario have to say. 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
4,242 reviews

Crew

8.6

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Overall

8.0

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
4,242 reviews
Southwest
8.0
Very good
4,242 reviews

Crew

8.6

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Overall

8.0

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.
Avelo Airlines
7.5
Good
Southwest
8.0
Very good
4,242 reviews

Crew

8.6

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Overall

8.0

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
8,929 reviews
Southwest
8.0
Very good
4,242 reviews

Crew

8.6

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Overall

8.0

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
10,000 reviews
Southwest
8.0
Very good
4,242 reviews

Crew

8.6

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Overall

8.0

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
3,172 reviews
Southwest
8.0
Very good
4,242 reviews

Crew

8.6

Boarding

8.1

Entertainment

7.5

Food

7.0

Comfort

8.0

Overall

8.0

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 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.

  • How long is the flight from California to Ontario?

    Frontier, United Airlines, and Southwest can get you from California to Ontario in just under 1h 05m. Your travel time will be generally consistent. California and Ontario are separated by a distance of 197 mi. All flights are typically nonstop.

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

    For one-way options, check prices for United Airlines. According to our data, you can fly for as low as $39. Users have also found prices from $49 and $72 on Southwest and Frontier, 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 Sacramento Intl - 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 7 airlines flying from California to Ontario

Discover the top 7 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 September 15, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$24Average$110FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$42Average$89FlexibilityNo cancel feeOn-time65%
United AirlinesCheapest$58Average$240FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$59Average$229FlexibilityNo cancel feeOn-time75%
DeltaCheapest$75Average$192FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$134Average$277FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$186Average$221FlexibilityNo cancel feeOn-time71%

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