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Ontario

$37+ 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 4/3. Fares are subject to change and may not be available on all flights or dates of travel.
LAX — ONT
Jan 26 — Feb 21
Sun 1/26
Sun 2/2
1 adult, Economy
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Cheap flight deals from California to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from California (USCA) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated January 21, 2025.

Round-trip from

$43
(Frontier)

One-way from

$37
(Trip.com)

Good round-trip deal

$57 or less

Good one-way deal

$51 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 January 21, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 1/20. 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.
Sun 2/29:59 pmSFO - ONT
Nonstop1h 25mFrontier
Fri 2/76:00 amONT - SFO
Nonstop1h 35mFrontier
Deal found 1/20$60
This Frontier deal was found by Cheapflights users on 1/20. 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.
Fri 2/74:49 pmLAS - ONT
Nonstop1h 08mFrontier
Fri 2/79:36 pmONT - LAS
Nonstop1h 13mFrontier
Deal found 1/20$60
This United Airlines deal was found by Cheapflights users on 1/21. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/298:25 amSFO - ONT
Nonstop1h 26mUnited Airlines
Thu 1/306:15 amONT - SFO
Nonstop1h 31mUnited Airlines
Deal found 1/21$77
This CheapOair deal was found by Cheapflights users on 1/21. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/145:45 pmSTS - ONT
Nonstop1h 26mAvelo Airlines
Mon 2/177:51 pmONT - STS
Nonstop1h 34mAvelo Airlines
Deal found 1/21$84
This Frontier deal was found by Cheapflights users on 1/21. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/61:11 pmSJC - ONT
1 stop10h 36mFrontier
Thu 3/610:44 amONT - SJC
1 stop6h 22mFrontier
Deal found 1/21$100
This Mytrip deal was found by Cheapflights users on 1/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/31:32 pmSMF - ONT
1 stop10h 27mFrontier
Mon 4/79:41 pmONT - SMF
1 stop15h 25mFrontier
Deal found 1/20$114
This FlightHub deal was found by Cheapflights users on 1/21. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/248:09 pmRNO - ONT
1 stop11h 16mFrontier
Mon 4/282:42 pmONT - RNO
1 stop4h 27mFrontier
Deal found 1/21$120
This Southwest deal was found by Cheapflights users on 1/21. 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.
Thu 2/207:45 amSJC - ONT
Nonstop1h 20mSouthwest
Sat 2/227:45 pmONT - SJC
Nonstop1h 15mSouthwest
Deal found 1/21$152
This Southwest deal was found by Cheapflights users on 1/20. 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.
Sat 2/85:35 amSFO - ONT
2 stops6h 30mSouthwest
Mon 2/103:30 pmONT - SFO
1 stop7h 20mSouthwest
Deal found 1/20$192
This Southwest deal was found by Cheapflights users on 1/21. 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.
Thu 2/206:15 amOAK - ONT
Nonstop1h 25mSouthwest
Thu 2/2011:10 amONT - OAK
Nonstop1h 25mSouthwest
Deal found 1/21$192
This American Airlines deal was found by Cheapflights users on 1/20. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/239:15 amSFO - ONT
1 stop6h 14mAmerican Airlines
Sat 1/2512:48 pmONT - SFO
1 stop6h 11mAmerican Airlines
Deal found 1/20$199
This United Airlines deal was found by Cheapflights users on 1/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/214:15 pmSMF - ONT
1 stop4h 25mUnited Airlines
Wed 2/266:00 amONT - SMF
1 stop3h 21mUnited Airlines
Deal found 1/20$208

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 January 21, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 2/5

8:25 am-9:51 am

Nonstop1h 26m

Ontario

Tue 2/11

10:47 am-12:20 pm

Nonstop1h 33m

$57

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Tue 3/11

1:53 pm-3:04 pm

Nonstop1h 11m

Ontario

Sat 3/22

2:43 pm-3:58 pm

Nonstop1h 15m

$57

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 2/20

8:06 am-9:34 am

Nonstop1h 28m

Ontario

Sun 2/23

8:26 am-10:02 am

Nonstop1h 36m

$58

Santa RosaOntario

STS - ONT

STSONT

Santa Rosa Sonoma County

Fri 2/14

5:45 pm-7:11 pm

Nonstop1h 26m

Ontario

Mon 2/17

7:51 pm-9:25 pm

Nonstop1h 34m

$84

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 2/6

1:11 pm-11:47 pm

1 stop10h 36m

Ontario

Thu 3/6

10:44 am-5:06 pm

1 stop6h 22m

$100

SacramentoOntario

SMF - ONT

SMFONT

Sacramento Intl

Thu 4/3

1:32 pm-11:59 pm

1 stop10h 27m

Ontario

Mon 4/7

9:41 pm-1:06 pm

1 stop15h 25m

$114

RenoOntario

RNO - ONT

RNOONT

Reno

Thu 4/24

8:09 pm-7:25 am

1 stop11h 16m

Ontario

Sun 4/27

12:59 am-11:36 am

1 stop10h 37m

$120

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 3/26

5:40 am-9:55 am

1 stop4h 15m

Ontario

Sat 3/29

5:45 pm-12:50 am

1 stop7h 05m

$152

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 2/20

7:45 am-9:05 am

Nonstop1h 20m

Ontario

Sat 2/22

7:45 pm-9:00 pm

Nonstop1h 15m

$152

OaklandOntario

OAK - ONT

OAKONT

Oakland

Thu 2/20

6:15 am-7:40 am

Nonstop1h 25m

Ontario

Thu 2/20

11:10 am-12:35 pm

Nonstop1h 25m

$192

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/21

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.

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 $310). 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 January 21, 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 January 21, 2025.
To help decide which airline to fly from California to Ontario, see what other customers have to say about United Airlines, Frontier and Southwest. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,662 reviews

Food

7.2

Boarding

8.2

Overall

8.1

Crew

8.7

Entertainment

7.7

Comfort

8.1

Reviews

1 / 10

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

Southwest
8.1
Very good
4,662 reviews
Southwest
8.1
Very good
4,662 reviews

Food

7.2

Boarding

8.2

Overall

8.1

Crew

8.7

Entertainment

7.7

Comfort

8.1

Reviews

1 / 10

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

Alaska Airlines
8.0
Very good
9,706 reviews
Southwest
8.1
Very good
4,662 reviews

Food

7.2

Boarding

8.2

Overall

8.1

Crew

8.7

Entertainment

7.7

Comfort

8.1

Reviews

1 / 10

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

Delta
8.0
Very good
8,521 reviews
Southwest
8.1
Very good
4,662 reviews

Food

7.2

Boarding

8.2

Overall

8.1

Crew

8.7

Entertainment

7.7

Comfort

8.1

Reviews

1 / 10

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

Avelo Airlines
7.5
Good
74 reviews
Southwest
8.1
Very good
4,662 reviews

Food

7.2

Boarding

8.2

Overall

8.1

Crew

8.7

Entertainment

7.7

Comfort

8.1

Reviews

1 / 10

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

United Airlines
7.4
Good
8,985 reviews
Southwest
8.1
Very good
4,662 reviews

Food

7.2

Boarding

8.2

Overall

8.1

Crew

8.7

Entertainment

7.7

Comfort

8.1

Reviews

1 / 10

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 $37. Users have also found prices from $42 and $59 on Avelo 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 $310). 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 January 21, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$32Average$116FlexibilityNo cancel feeOn-time65%
FrontierCheapest$36Average$99FlexibilityNo cancel feeOn-time62%
DeltaCheapest$45Average$216FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$55Average$320FlexibilityNo cancel feeOn-time75%
Breeze AirwaysCheapest$78Average$155FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$124Average$327FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$194Average$280FlexibilityNo cancel feeOn-time63%
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