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$67+ Cheap flights from Ontario to San Diego (ONT - SAN)

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 12/15. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Nov 29 — Dec 61
Sat 11/29
Sat 12/6
1 adult, Economy
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Cheap flight deals from Ontario to San Diego

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to San Diego (SAN). 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 October 30, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$154
(Kiwi.com)

One-way from

$67
(Kiwi.com)

Popular in

October

Cheapest in

January

Average price

$249
Provider with most accurate pricing for Ontario-San Diego flight deals.
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Provider most trusted by Cheapflights users for Ontario-San Diego flights.
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From Ontario to San Diego
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One-way flight from Ontario to San Diego
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Highest demand for flights based on searches. 13% potential increase in price ($32 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
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Average for round-trip flights in October 2025
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Find flight deals from Ontario to San Diego

Cheapest flights from Ontario to San Diego
Explore the most affordable flight options available from Ontario to San Diego. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 30, 2025.

This Kiwi.com deal was found by Cheapflights users on 10/29. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/136:00 amONT - SAN
2 stops10h 57mFrontier
Mon 11/1712:12 pmSAN - ONT
1 stop11h 38mFrontier
Deal found 10/29$154
This Kiwi.com deal was found by Cheapflights users on 10/29. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/266:01 pmONT - SAN
2 stops38h 00mFrontier
Wed 12/36:25 amSAN - ONT
1 stop28h 44mFrontier
Deal found 10/29$191
This Kiwi.com deal was found by Cheapflights users on 10/30. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/97:44 pmONT - SAN
1 stop4h 04mFrontier
Mon 11/1012:12 pmSAN - ONT
1 stop11h 38mFrontier
Deal found 10/30$363
This Kiwi.com deal was found by Cheapflights users on 10/27. 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.
Fri 10/3110:40 pmONT - SAN
1 stop17h 18mFrontier
Sun 11/23:59 pmSAN - ONT
1 stop15h 18mFrontier
Deal found 10/27$378
This United Airlines deal was found by Cheapflights users on 10/28. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/115:05 amONT - SAN
1 stop9h 59mUnited Airlines
Sun 1/116:55 pmSAN - ONT
1 stop17h 52mUnited Airlines
Deal found 10/28$403
This American Airlines deal was found by Cheapflights users on 10/29. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/226:11 amONT - SAN
1 stop12h 13mAmerican Airlines
Wed 11/266:30 amSAN - ONT
1 stop11h 50mAmerican Airlines
Deal found 10/29$419

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to San Diego 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 October 30, 2025.
Use the filters below to find and compare flights from Ontario to San Diego that are best for you.

Fly from

Ontario

Fly to

San Diego

Route

Depart

Return

Price

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 11/13

6:00 am-4:57 pm

2 stops10h 57m

San Diego

Mon 11/17

12:12 pm-11:50 pm

1 stop11h 38m

$154

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 11/26

6:01 pm-8:01 am

2 stops38h 00m

San Diego

Wed 12/3

6:25 am-11:09 am

1 stop28h 44m

$191

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sat 2/28

7:00 am-12:58 pm

1 stop5h 58m

San Diego

Wed 3/4

10:45 am-4:53 pm

1 stop6h 08m

$339

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Mon 2/23

7:50 pm-11:56 am

1 stop16h 06m

San Diego

Fri 2/27

7:30 pm-11:41 am

1 stop16h 11m

$359

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sun 11/9

7:44 pm-11:48 pm

1 stop4h 04m

San Diego

Mon 11/10

12:12 pm-11:50 pm

1 stop11h 38m

$363

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Fri 12/5

1:26 pm-8:02 pm

1 stop6h 36m

San Diego

Sat 12/6

6:55 am-12:46 pm

1 stop5h 51m

$398

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 12/11

5:05 am-3:04 pm

1 stop9h 59m

San Diego

Sun 1/11

6:55 pm-12:47 pm

1 stop17h 52m

$403

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 1/6

6:05 pm-12:07 am

1 stop6h 02m

San Diego

Thu 3/26

9:20 am-5:12 pm

1 stop7h 52m

$417

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sat 11/22

6:11 am-6:24 pm

1 stop12h 13m

San Diego

Wed 11/26

6:30 am-6:20 pm

1 stop11h 50m

$419

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 1/7

7:56 pm-9:15 am

1 stop13h 19m

$157

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/27

Showing 1-10 of 19 results
1
2

Compare providers for flights from Ontario to San Diego

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to San Diego in October.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Ontario-San Diego flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Ontario-San Diego flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Ontario-San Diego flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-San Diego flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-San Diego flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Ontario to San Diego

Have a flexible travel schedule? Discover the best time to fly to San Diego from Ontario 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 Ontario to San Diego

What is the cheapest month to book a flight from Ontario to San Diego?

Currently, January is the cheapest month in which you can book a flight from Ontario to San Diego (average of $63). Flying from Ontario to San Diego in October is currently the most expensive (average of $179). 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 ONT to SAN?

Find hourly flight availability from Ontario to San Diego. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 30, 2025.

It’s typically best to fly out from Ontario to San Diego in the evening. Doing so could potentially save you 43% on the flight price compared to flying in the afternoon, which is usually more expensive.

Related info for your journey

Find useful and relevant information for your journey from Ontario to San Diego. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Ontario to San Diego?

    A quick flight from Ontario to San Diego can take about 5h 58m. Frontier provides one of the quickest options available for as low as $339. Ontario and San Diego are separated by a distance of 94 mi. This flight may include one or multiple stops.

  • Can I find deals for flights from Ontario to San Diego that include hotel bookings?

    Yes. In addition to deals on Ontario to San Diego flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Ontario to San Diego?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to San Diego.

  • Can I find deals for business class flights from Ontario to San Diego?

    Yes. Cheapflights offers flight deals from Ontario to San Diego 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 Ontario to San Diego?

    Currently, January is the cheapest month in which you can book a flight from Ontario to San Diego (average of $63). Flying from Ontario to San Diego in October is currently the most expensive (average of $179). 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

Traveling to a place near San Diego?

Book flights to San Diego if you plan to visit one of these locations
El Cajon
Chula Vista
Coronado
La Mesa
Poway
Lemon Grove
National City

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