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San Diego

$95+ 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 8/15. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Jul 9 — Jul 161
Thu 7/9
Thu 7/16
1 adult, Economy
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1. Tell us where you want to go

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Cheap 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 June 9, 2026.

This Kiwi.com deal was found by Cheapflights users on 6/5. 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.
Mon 8/38:58 am
ONT
-
SAN
1 stop15h 06m
Frontier
Tue 8/47:46 pm
SAN
-
ONT
1 stop17h 02m
Frontier
Deal found 6/5$140
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/73:40 pm
ONT
-
SAN
1 stop22h 28m
Frontier
Tue 7/143:03 pm
SAN
-
ONT
1 stop17h 00m
Frontier
Deal found 6/9$191
This Kiwi.com deal was found by Cheapflights users on 6/6. 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.
Sat 7/188:58 am
ONT
-
SAN
1 stop15h 06m
Frontier
Fri 7/248:51 pm
SAN
-
ONT
1 stop18h 23m
Frontier
Deal found 6/6$263
This Kiwi.com deal was found by Cheapflights users on 6/8. 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.
Mon 7/63:40 pm
ONT
-
SAN
1 stop22h 28m
Frontier
Mon 7/137:46 pm
SAN
-
ONT
1 stop17h 07m
Frontier
Deal found 6/8$274
This Kiwi.com deal was found by Cheapflights users on 6/6. 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 7/18:36 pm
ONT
-
SAN
1 stop27h 39m
Frontier
Mon 7/68:51 pm
SAN
-
ONT
1 stop11h 12m
Frontier
Deal found 6/6$279
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/238:58 am
ONT
-
SAN
1 stop15h 06m
Frontier
Sat 7/257:46 pm
SAN
-
ONT
1 stop15h 21m
Frontier
Deal found 6/9$298
This Kiwi.com deal was found by Cheapflights users on 6/7. 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 8/1411:47 am
ONT
-
SAN
1 stop8h 19m
Frontier
Sun 8/167:45 pm
SAN
-
ONT
1 stop15h 17m
Frontier
Deal found 6/7$304
This Kiwi.com deal was found by Cheapflights users on 6/8. 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 7/243:40 pm
ONT
-
SAN
1 stop4h 26m
Frontier
Sat 7/258:51 pm
SAN
-
ONT
1 stop11h 12m
Frontier
Deal found 6/8$308

Find 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 June 9, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$140
(Kiwi.com)

One-way from

$95
(Kiwi.com)

Popular in

January

Cheapest in

February

Average price

$244
Provider with most accurate pricing for Ontario-San Diego flight deals.
Search Deals
Provider most trusted by Cheapflights users for Ontario-San Diego flights.
Search Deals
From Ontario to San Diego
Search Deals
One-way flight from Ontario to San Diego
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($15 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($8 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2026
Search Deals

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 June 9, 2026.
Use the filters below to find and compare flights from Ontario to San Diego that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Mon 8/3

8:58 am-12:04 am

1 stop15h 06m

San Diego

Tue 8/4

7:46 pm-12:48 pm

1 stop17h 02m

$140

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sat 7/18

8:58 am-12:04 am

1 stop15h 06m

San Diego

Fri 7/24

8:51 pm-3:14 pm

1 stop18h 23m

$263

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 7/23

8:58 am-12:04 am

1 stop15h 06m

San Diego

Sat 7/25

7:46 pm-11:07 am

1 stop15h 21m

$298

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 9/17

4:27 pm-8:36 pm

1 stop4h 09m

San Diego

Sat 9/19

7:57 am-3:47 pm

1 stop7h 50m

$388

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Fri 8/28

4:27 pm-8:05 am

1 stop15h 38m

San Diego

Fri 9/4

9:59 pm-3:52 pm

1 stop17h 53m

$388

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 10/20

5:48 pm-8:10 am

1 stop14h 22m

San Diego

Wed 10/21

10:29 am-4:02 pm

1 stop5h 33m

$402

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 8/18

6:00 am-8:45 pm

1 stop14h 45m

San Diego

Wed 8/19

9:49 am-6:16 pm

1 stop8h 27m

$403

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 9/17

12:12 pm-9:16 pm

1 stop9h 04m

San Diego

Sun 9/20

9:59 pm-3:47 pm

1 stop17h 48m

$411

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Fri 6/26

6:43 pm-8:15 am

1 stop13h 32m

San Diego

Sun 6/28

8:18 am-6:03 pm

1 stop9h 45m

$420
Quickest round-trip

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Fri 7/24

1:20 pm-4:45 pm

1 stop3h 25m

San Diego

Sat 7/25

4:10 pm-10:05 pm

2 stops5h 55m

$456

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/6

Showing 1-10 of 23 resultsSorted by cheapest first
1
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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 June.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice 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 FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-San Diego flight deals on Cheapflights vs. FlightHub >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 FlightHub the most. FlightHub 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.

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 15h 06m. Frontier provides one of the quickest options available for as low as $140. Ontario and San Diego are separated by a distance of 94 mi.

  • 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.

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
National City
Poway
Coronado
La Mesa
Santee
Julian
Lemon Grove

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