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$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 6/23. Fares are subject to change and may not be available on all flights or dates of travel.
LAX — ONT
May 6 — May 131
Tue 5/6
Tue 5/13
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 May 1, 2025.

Round-trip from

$56
(Cheapflightsfares)

One-way from

$38
(Cheapflightsfares)

Good round-trip deal

$69 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 May 1, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 4/30. 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.
Wed 5/2111:00 amLAS - ONT
Nonstop1h 08mFrontier
Sat 5/246:00 amONT - LAS
Nonstop1h 16mFrontier
Deal found 4/30$56
This Frontier deal was found by Cheapflights users on 4/29. 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.
Sat 5/1010:48 amSFO - ONT
Nonstop1h 27mFrontier
Mon 5/128:24 amONT - SFO
Nonstop1h 38mFrontier
Deal found 4/29$59
This United Airlines deal was found by Cheapflights users on 4/30. 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.
Thu 6/54:12 pmSFO - ONT
Nonstop1h 27mUnited Airlines
Mon 6/96:41 pmONT - SFO
Nonstop1h 27mUnited Airlines
Deal found 4/30$91
This Southwest deal was found by Cheapflights users on 4/29. 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 5/135:15 amSFO - ONT
1 stop5h 20mSouthwest
Wed 5/143:40 pmONT - SFO
2 stops7h 00mSouthwest
Deal found 4/29$156
This Southwest deal was found by Cheapflights users on 4/30. 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 6/107:25 amLAS - ONT
1 stop5h 00mSouthwest
Tue 6/179:35 pmONT - LAS
Nonstop1h 05mSouthwest
Deal found 4/30$167
This Southwest deal was found by Cheapflights users on 4/30. 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 5/216:55 amSJC - ONT
Nonstop1h 15mSouthwest
Wed 5/217:00 pmONT - SJC
Nonstop1h 10mSouthwest
Deal found 4/30$175
This Southwest deal was found by Cheapflights users on 4/29. 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 5/286:55 amOAK - ONT
Nonstop1h 20mSouthwest
Wed 6/46:20 amONT - OAK
Nonstop1h 20mSouthwest
Deal found 4/29$175
This Frontier deal was found by Cheapflights users on 4/29. 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 5/912:36 pmRNO - ONT
1 stop11h 23mFrontier
Mon 5/122:28 pmONT - RNO
1 stop4h 45mFrontier
Deal found 4/29$178
This Frontier deal was found by Cheapflights users on 4/30. 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 5/1512:04 pmSJC - ONT
1 stop11h 55mFrontier
Sun 5/1812:59 amONT - SJC
1 stop10h 21mFrontier
Deal found 4/30$180
This CheapOair deal was found by Cheapflights users on 4/28. 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 5/911:56 amSMF - ONT
1 stop12h 03mFrontier
Sun 5/1812:59 amONT - SMF
1 stop10h 07mFrontier
Deal found 4/28$181
This Delta deal was found by Cheapflights users on 4/29. 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.
Tue 9/27:00 pmSMF - ONT
1 stop4h 43mDelta
Tue 9/99:55 amONT - SMF
1 stop6h 08mDelta
Deal found 4/29$185
This Southwest deal was found by Cheapflights users on 4/29. 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 5/206:40 amSMF - ONT
Nonstop1h 20mSouthwest
Thu 5/223:10 pmONT - SMF
Nonstop1h 25mSouthwest
Deal found 4/29$186

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 May 1, 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

Wed 5/21

11:00 am-12:08 pm

Nonstop1h 08m

Ontario

Sat 5/24

6:00 am-7:16 am

Nonstop1h 16m

$56

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 5/10

7:05 pm-8:34 pm

Nonstop1h 29m

Ontario

Mon 5/19

6:00 am-7:27 am

Nonstop1h 27m

$67

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Fri 5/30

10:11 pm-11:36 pm

Nonstop1h 25m

Ontario

Fri 6/6

9:41 pm-11:15 pm

Nonstop1h 34m

$68

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Tue 5/6

5:15 am-12:20 pm

1 stop7h 05m

Ontario

Wed 5/7

4:30 pm-10:55 pm

1 stop6h 25m

$167

Las VegasOntario

LAS - ONT

LASONT

Las Vegas Harry Reid Intl

Tue 6/10

7:25 am-12:25 pm

1 stop5h 00m

Ontario

Tue 6/17

9:35 pm-10:40 pm

Nonstop1h 05m

$167

San JoseOntario

SJC - ONT

SJCONT

San Jose

Wed 6/11

12:10 pm-1:25 pm

Nonstop1h 15m

Ontario

Wed 6/18

6:45 am-8:00 am

Nonstop1h 15m

$175

OaklandOntario

OAK - ONT

OAKONT

Oakland

Wed 5/28

6:55 am-8:15 am

Nonstop1h 20m

Ontario

Wed 6/4

6:20 am-7:40 am

Nonstop1h 20m

$175

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 5/15

12:04 pm-11:59 pm

1 stop11h 55m

Ontario

Sun 5/18

12:59 am-11:20 am

1 stop10h 21m

$180

RenoOntario

RNO - ONT

RNOONT

Reno

Fri 5/16

12:26 pm-11:59 pm

1 stop11h 33m

Ontario

Mon 5/19

2:28 pm-7:13 pm

1 stop4h 45m

$180

SacramentoOntario

SMF - ONT

SMFONT

Sacramento Intl

Tue 6/24

6:55 am-11:00 am

1 stop4h 05m

Ontario

Tue 6/24

4:25 pm-5:50 pm

Nonstop1h 25m

$185

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/30

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 May 1, 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 May 1, 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
9,972 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Food

7.1

Comfort

7.9

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
9,972 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Food

7.1

Comfort

7.9

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
4,294 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Food

7.1

Comfort

7.9

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
7,934 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Food

7.1

Comfort

7.9

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
2,409 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Food

7.1

Comfort

7.9

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
8,696 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Overall

8.0

Entertainment

7.1

Crew

8.5

Boarding

8.1

Food

7.1

Comfort

7.9

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 Frontier. According to our data, you can fly for as low as $38. Users have also found prices from $59 and $76 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, Sacramento Intl - 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 May 1, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$29Average$100FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$32Average$106FlexibilityNo cancel feeOn-time65%
DeltaCheapest$45Average$173FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$59Average$334FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$71Average$305FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$147Average$276FlexibilityNo cancel feeOn-time63%

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