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Ontario

$49+ 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 8/25. Fares are subject to change and may not be available on all flights or dates of travel.
LAX — ONT
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
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 June 12, 2025.

Round-trip from

$57
(United Airlines)

One-way from

$49
(Southwest)

Good round-trip deal

$58 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 June 12, 2025.

This United Airlines deal was found by Cheapflights users on 6/10. 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 7/1110:45 amSFO - ONT
Nonstop1h 29mUnited Airlines
Sat 7/191:19 pmONT - SFO
Nonstop1h 27mUnited Airlines
Deal found 6/10$57
This Frontier deal was found by Cheapflights users on 6/12. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/53:09 pmLAS - ONT
Nonstop1h 11mFrontier
Thu 8/75:14 pmONT - LAS
Nonstop1h 14mFrontier
Deal found 6/12$77
This Frontier deal was found by Cheapflights users on 6/12. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/1110:11 pmSFO - ONT
Nonstop1h 29mFrontier
Mon 7/149:41 pmONT - SFO
Nonstop1h 33mFrontier
Deal found 6/12$89
This Southwest deal was found by Cheapflights users on 6/11. 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 9/86:30 amSJC - ONT
Nonstop1h 25mSouthwest
Tue 9/96:20 pmONT - SJC
Nonstop1h 15mSouthwest
Deal found 6/11$97
This Southwest deal was found by Cheapflights users on 6/11. 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 9/81:10 pmOAK - ONT
Nonstop1h 20mSouthwest
Tue 9/3011:00 amONT - OAK
Nonstop1h 20mSouthwest
Deal found 6/11$97
This Southwest deal was found by Cheapflights users on 6/10. 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 9/32:55 pmLAS - ONT
1 stop5h 20mSouthwest
Fri 9/55:40 amONT - LAS
Nonstop1h 05mSouthwest
Deal found 6/10$149
This Frontier deal was found by Cheapflights users on 6/11. 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 9/28:00 amSAN - ONT
1 stop8h 18mFrontier
Thu 9/117:35 pmONT - SAN
1 stop3h 29mFrontier
Deal found 6/11$153
This Southwest deal was found by Cheapflights users on 6/11. 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 9/85:15 amSFO - ONT
2 stops7h 05mSouthwest
Mon 9/82:15 pmONT - SFO
2 stops9h 05mSouthwest
Deal found 6/11$161
This Frontier deal was found by Cheapflights users on 6/12. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/77:00 pmSJC - ONT
1 stop16h 53mFrontier
Mon 8/116:00 amONT - SJC
1 stop7h 17mFrontier
Deal found 6/12$167
This Southwest deal was found by Cheapflights users on 6/11. 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 8/18:50 pmSMF - ONT
Nonstop1h 25mSouthwest
Mon 8/48:20 amONT - SMF
Nonstop1h 20mSouthwest
Deal found 6/11$177
This Delta deal was found by Cheapflights users on 6/9. 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.
Thu 8/217:05 pmSMF - ONT
1 stop4h 35mDelta
Mon 8/256:05 amONT - SMF
1 stop6h 25mDelta
Deal found 6/9$183
This American Airlines deal was found by Cheapflights users on 6/11. 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 7/55:32 amSFO - ONT
1 stop6h 28mAmerican Airlines
Sat 7/126:53 pmONT - SFO
1 stop4h 49mAmerican Airlines
Deal found 6/11$187

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 June 12, 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

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Fri 7/11

10:45 am-12:14 pm

Nonstop1h 29m

Ontario

Sat 7/19

1:19 pm-2:46 pm

Nonstop1h 27m

$57

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Tue 8/5

3:09 pm-4:20 pm

Nonstop1h 11m

Ontario

Thu 8/7

5:14 pm-6:28 pm

Nonstop1h 14m

$77

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Fri 7/11

10:11 pm-11:40 pm

Nonstop1h 29m

Ontario

Mon 7/14

9:41 pm-11:14 pm

Nonstop1h 33m

$89

San JoseOntario

SJC - ONT

SJCONT

San Jose

Mon 9/8

6:30 am-7:55 am

Nonstop1h 25m

Ontario

Tue 9/9

6:20 pm-7:35 pm

Nonstop1h 15m

$97

OaklandOntario

OAK - ONT

OAKONT

Oakland

Mon 9/8

1:10 pm-2:30 pm

Nonstop1h 20m

Ontario

Tue 9/30

11:00 am-12:20 pm

Nonstop1h 20m

$97

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Wed 9/3

2:55 pm-8:15 pm

1 stop5h 20m

Ontario

Fri 9/5

5:40 am-6:45 am

Nonstop1h 05m

$149

San DiegoOntario

SAN - ONT

SANONT

San Diego

Tue 9/2

8:00 am-4:18 pm

1 stop8h 18m

Ontario

Thu 9/11

7:35 pm-11:04 pm

1 stop3h 29m

$153

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Mon 9/8

5:15 am-12:20 pm

2 stops7h 05m

Ontario

Mon 9/8

2:15 pm-11:20 pm

2 stops9h 05m

$161

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 8/7

7:00 pm-11:53 am

1 stop16h 53m

Ontario

Mon 8/11

6:00 am-1:17 pm

1 stop7h 17m

$167

SacramentoOntario

SMF - ONT

SMFONT

Sacramento Intl

Fri 8/1

8:50 pm-10:15 pm

Nonstop1h 25m

Ontario

Mon 8/4

8:20 am-9:40 am

Nonstop1h 20m

$177

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

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 June 12, 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 June 12, 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
10,000 reviews

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,287 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,950 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Hawaiian Airlines
7.9
Good
2,494 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,790 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Boarding

8.1

Food

7.1

Crew

8.5

Comfort

7.8

Overall

8.0

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

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 Southwest. According to our data, you can fly for as low as $49. Users have also found prices from $52 and $60 on Frontier 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 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 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 June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$27Average$103FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$32Average$103FlexibilityNo cancel feeOn-time65%
United AirlinesCheapest$58Average$289FlexibilityNo cancel feeOn-time69%
DeltaCheapest$58Average$179FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$59Average$351FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$149Average$275FlexibilityNo cancel feeOn-time63%

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