HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$36+ 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 2/28. Fares are subject to change and may not be available on all flights or dates of travel.
LAX — ONT
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from California to Ontario with Cheapflights

1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”
2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.
3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

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 February 20, 2025.

Round-trip from

$42
(Cheapflightsfares)

One-way from

$36
(Cheapflightsfares)

Good round-trip deal

$58 or less

Good one-way deal

$28 or less
From California to Ontario
Search Deals
One-way flight from California to Ontario
Search Deals
Price to beat on a round-trip flight from California to Ontario.
Search Deals
Price to beat on a one-way flight from California to Ontario.
Search Deals

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 February 20, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 2/19. 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 5/108:34 amSFO - ONT
Nonstop1h 28mFrontier
Fri 5/168:24 amONT - SFO
Nonstop1h 38mFrontier
Deal found 2/19$59
This FlightHub deal was found by Cheapflights users on 2/19. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/110:10 amLAS - ONT
Nonstop1h 07mFrontier
Sun 3/29:22 pmONT - LAS
Nonstop1h 13mFrontier
Deal found 2/19$61
This United Airlines deal was found by Cheapflights users on 2/19. 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.
Sat 3/89:15 pmSFO - ONT
Nonstop1h 30mUnited Airlines
Mon 3/106:00 amONT - SFO
Nonstop1h 29mUnited Airlines
Deal found 2/19$92
This Frontier deal was found by Cheapflights users on 2/19. 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 5/112:04 pmSJC - ONT
1 stop11h 55mFrontier
Thu 5/810:52 amONT - SJC
1 stop7h 49mFrontier
Deal found 2/19$100
This Frontier deal was found by Cheapflights users on 2/19. 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 4/212:27 pmRNO - ONT
1 stop11h 32mFrontier
Tue 4/812:59 amONT - RNO
1 stop10h 27mFrontier
Deal found 2/19$100
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.
Thu 3/135:55 pmSJC - ONT
Nonstop1h 20mSouthwest
Mon 3/175:05 pmONT - SJC
Nonstop1h 15mSouthwest
Deal found 2/20$117
This Southwest deal was found by Cheapflights users on 2/19. 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 4/228:50 amLAS - ONT
1 stop3h 30mSouthwest
Wed 4/238:45 pmONT - LAS
Nonstop1h 05mSouthwest
Deal found 2/19$117
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/181:22 pmSMF - ONT
1 stop10h 37mFrontier
Mon 3/2412:59 amONT - SMF
1 stop11h 28mFrontier
Deal found 2/20$129
This Southwest deal was found by Cheapflights users on 2/19. 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 3/135:30 amSFO - ONT
1 stop5h 00mSouthwest
Thu 3/135:30 pmONT - SFO
1 stop5h 00mSouthwest
Deal found 2/19$151
This Expedia 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/12:06 pmSMF - ONT
1 stop6h 43mMultiple Airlines
Tue 4/85:44 pmONT - SMF
1 stop4h 46mMultiple Airlines
Deal found 2/20$196
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.
Thu 3/1310:55 amSMF - ONT
Nonstop1h 25mSouthwest
Tue 3/1810:00 amONT - SMF
Nonstop1h 25mSouthwest
Deal found 2/20$197
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.
Mon 3/248:55 amOAK - ONT
Nonstop1h 25mSouthwest
Thu 3/276:25 pmONT - OAK
Nonstop1h 25mSouthwest
Deal found 2/20$197

Find flights from California to Ontario within your budget

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 February 20, 2025.

Fly from

California

Fly to

Ontario

Route

Depart

Return

Price

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sun 4/6

8:35 am-10:03 am

Nonstop1h 28m

Ontario

Mon 4/7

8:26 am-10:07 am

Nonstop1h 41m

$54

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Sun 4/6

6:20 am-7:25 am

Nonstop1h 05m

Ontario

Mon 4/7

10:53 am-12:02 pm

Nonstop1h 09m

$54

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 3/8

9:15 pm-10:45 pm

Nonstop1h 30m

Ontario

Mon 3/10

6:00 am-7:29 am

Nonstop1h 29m

$92

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 5/1

12:04 pm-11:59 pm

1 stop11h 55m

Ontario

Wed 5/7

12:59 am-11:04 am

1 stop10h 05m

$100

RenoOntario

RNO - ONT

RNOONT

Reno

Wed 4/2

12:27 pm-11:59 pm

1 stop11h 32m

Ontario

Tue 4/8

12:59 am-11:26 am

1 stop10h 27m

$100

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 3/13

5:55 pm-7:15 pm

Nonstop1h 20m

Ontario

Mon 3/17

5:05 pm-6:20 pm

Nonstop1h 15m

$117

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Tue 4/22

8:45 pm-9:45 pm

Nonstop1h 00m

Ontario

Wed 4/23

11:25 am-2:40 pm

1 stop3h 15m

$117

SacramentoOntario

SMF - ONT

SMFONT

Sacramento Intl

Tue 3/18

1:22 pm-11:59 pm

1 stop10h 37m

Ontario

Mon 3/24

12:59 am-12:27 pm

1 stop11h 28m

$129

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 3/13

5:30 am-10:30 am

1 stop5h 00m

Ontario

Thu 3/13

5:30 pm-10:30 pm

1 stop5h 00m

$151

SacramentoOntario

SMF - ONT

SMFONT

Sacramento Intl

Tue 4/1

2:06 pm-8:49 pm

1 stop6h 43m

Ontario

Tue 4/8

5:44 pm-10:30 pm

1 stop4h 46m

$196

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/19

Showing 1-10 of 60 results
1
2
3
...
6

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.

Travel insights for flights from California to Ontario

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

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 $315). 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 February 20, 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 February 20, 2025.
To help decide which airline to fly from California to Ontario, see what other customers have to say about Southwest, Alaska Airlines and Delta. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,411 reviews

Food

7.1

Crew

8.7

Entertainment

7.6

Boarding

8.2

Comfort

8.1

Overall

8.1

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Southwest
8.1
Very good
4,411 reviews
Southwest
8.1
Very good
4,411 reviews

Food

7.1

Crew

8.7

Entertainment

7.6

Boarding

8.2

Comfort

8.1

Overall

8.1

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Alaska Airlines
8.0
Very good
9,697 reviews
Southwest
8.1
Very good
4,411 reviews

Food

7.1

Crew

8.7

Entertainment

7.6

Boarding

8.2

Comfort

8.1

Overall

8.1

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Delta
8.0
Very good
8,219 reviews
Southwest
8.1
Very good
4,411 reviews

Food

7.1

Crew

8.7

Entertainment

7.6

Boarding

8.2

Comfort

8.1

Overall

8.1

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Hawaiian Airlines
7.9
Good
2,317 reviews
Southwest
8.1
Very good
4,411 reviews

Food

7.1

Crew

8.7

Entertainment

7.6

Boarding

8.2

Comfort

8.1

Overall

8.1

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

United Airlines
7.4
Good
8,765 reviews
Southwest
8.1
Very good
4,411 reviews

Food

7.1

Crew

8.7

Entertainment

7.6

Boarding

8.2

Comfort

8.1

Overall

8.1

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

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 $36. Users have also found prices from $59 and $59 on United Airlines and Southwest, 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 $315). 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for California to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
John F Kennedy Intl to Los Angeles flights
John F Kennedy Intl to Las Vegas flights
Newark to Los Angeles flights
O'Hare Intl to Las Vegas flights
Dallas/Fort Worth to Las Vegas flights
Newark to Las Vegas flights
Seattle to Los Angeles flights
John F Kennedy Intl to San Francisco flights
Seattle to Las Vegas flights
Minneapolis to Las Vegas flights
Newark to San Francisco flights
Dulles Intl to Las Vegas flights
San Francisco to Las Vegas flights
O'Hare Intl to Los Angeles flights
LaGuardia to Los Angeles flights
LaGuardia to Las Vegas flights
Boston to Las Vegas flights
Reagan-National to Los Angeles flights
Denver to Las Vegas flights
Dallas/Fort Worth to Los Angeles flights
Dulles Intl to Los Angeles flights
San Jose to Las Vegas flights
Detroit to Las Vegas flights
Seattle to San Diego flights
Atlanta to Las Vegas flights
San Francisco to Los Angeles flights
Seattle to San Francisco flights
Seattle to Santa Ana flights
Midway to Las Vegas flights
Los Angeles to Las Vegas flights
Baltimore to Las Vegas flights
Boston to Los Angeles flights
Baltimore to Los Angeles flights
Reagan-National to Las Vegas flights
Hobby to Las Vegas flights
Santa Ana to Las Vegas flights
O'Hare Intl to San Francisco flights
Oakland to Las Vegas flights
Burbank to Las Vegas flights
Oakland to Los Angeles flights
Newark to Burbank flights
Los Angeles to San Francisco flights
Boston to San Francisco flights
Cincinnati to Las Vegas flights
Dulles Intl to San Francisco flights
John F Kennedy Intl to San Diego flights
San Jose to Los Angeles flights
San Francisco to Ontario flights
George Bush Intcntl to Las Vegas flights
Philadelphia to Las Vegas flights

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 February 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$30Average$97FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$36Average$117FlexibilityNo cancel feeOn-time65%
DeltaCheapest$45Average$218FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$45Average$318FlexibilityNo cancel feeOn-time75%
Breeze AirwaysCheapest$78Average$116FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$112Average$323FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$178Average$278FlexibilityNo cancel feeOn-time63%
100% Free
Cheapflights is completely free to use, so you can start saving the moment you arrive.
Book with Flexibility
Our users can plan ahead with confidence and find flights with no change fees
Travel Smart
Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.