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San Diego

$73+ 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 3/1. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Mar 13 — Mar 201
Fri 3/13
Fri 3/20
1 adult, Economy
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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 February 11, 2026.

This Kiwi.com deal was found by Cheapflights users on 2/9. 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 3/106:15 am
ONT
-
SAN
1 stop14h 59m
Frontier
Tue 3/178:25 am
SAN
-
ONT
1 stop15h 34m
Frontier
Deal found 2/9$115
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Tue 3/38:40 am
ONT
-
SAN
1 stop13h 01m
Frontier
Wed 3/118:25 am
SAN
-
ONT
1 stop15h 34m
Frontier
Deal found 2/8$117
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Tue 3/38:40 am
ONT
-
SAN
1 stop13h 01m
Frontier
Mon 3/99:58 pm
SAN
-
ONT
1 stop15h 30m
Frontier
Deal found 2/8$124
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Tue 3/38:40 am
ONT
-
SAN
1 stop13h 01m
Frontier
Thu 3/52:38 pm
SAN
-
ONT
1 stop17h 28m
Frontier
Deal found 2/8$125
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Wed 3/47:17 pm
ONT
-
SAN
1 stop20h 00m
Frontier
Mon 3/99:58 pm
SAN
-
ONT
1 stop15h 30m
Frontier
Deal found 2/8$131
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Sat 3/76:15 am
ONT
-
SAN
1 stop14h 18m
Frontier
Tue 3/108:25 am
SAN
-
ONT
1 stop15h 34m
Frontier
Deal found 2/8$133
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Tue 3/38:40 am
ONT
-
SAN
1 stop13h 01m
Frontier
Fri 3/69:58 pm
SAN
-
ONT
1 stop15h 53m
Frontier
Deal found 2/8$135
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Sat 3/76:15 am
ONT
-
SAN
1 stop14h 18m
Frontier
Mon 3/99:58 pm
SAN
-
ONT
1 stop15h 30m
Frontier
Deal found 2/8$136
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Tue 3/38:40 am
ONT
-
SAN
2 stops11h 44m
Frontier
Tue 3/108:25 am
SAN
-
ONT
1 stop15h 34m
Frontier
Deal found 2/8$145
This Kiwi.com deal was found by Cheapflights users on 2/8. 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.
Thu 3/52:08 pm
ONT
-
SAN
1 stop10h 00m
Frontier
Fri 3/69:58 pm
SAN
-
ONT
1 stop15h 53m
Frontier
Deal found 2/8$147

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 February 11, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$115
(Kiwi.com)

One-way from

$73
(Kiwi.com)

Popular in

January

Cheapest in

July

Average price

$267
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. 21% potential increase in price ($62 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($10 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 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 February 11, 2026.
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 3/5

7:22 pm-4:13 pm

1 stop20h 51m

San Diego

Tue 3/10

8:25 am-11:59 pm

1 stop15h 34m

$124

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 3/4

7:17 pm-3:17 pm

1 stop20h 00m

San Diego

Tue 3/10

8:25 am-11:59 pm

1 stop15h 34m

$124

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 3/3

8:40 am-9:41 pm

1 stop13h 01m

San Diego

Mon 3/9

9:58 pm-1:28 pm

1 stop15h 30m

$124

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 3/3

8:40 am-9:41 pm

1 stop13h 01m

San Diego

Thu 3/5

2:38 pm-8:06 am

1 stop17h 28m

$125

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 3/5

7:22 pm-4:13 pm

1 stop20h 51m

San Diego

Sun 3/8

9:07 pm-8:06 am

1 stop10h 59m

$131

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 2/25

3:22 pm-3:17 pm

1 stop23h 55m

San Diego

Sun 3/1

2:52 pm-1:11 pm

1 stop22h 19m

$131

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sat 3/7

6:15 am-8:33 pm

1 stop14h 18m

San Diego

Wed 3/11

8:25 am-11:59 pm

1 stop15h 34m

$133

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sat 3/7

6:15 am-8:33 pm

1 stop14h 18m

San Diego

Tue 3/10

8:25 am-11:59 pm

1 stop15h 34m

$133

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sat 3/7

6:15 am-8:33 pm

1 stop14h 18m

San Diego

Sun 3/8

9:07 pm-8:06 am

1 stop10h 59m

$136

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 3/10

2:23 pm-12:08 am

2 stops33h 45m

San Diego

Tue 3/17

8:25 am-11:59 pm

1 stop15h 34m

$139

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/9

Showing 1-10 of 20 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 February.
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.

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, April is the cheapest month in which you can book a flight from Ontario to San Diego (average of $79). Flying from Ontario to San Diego in January 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.

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 20h 51m. Frontier provides one of the quickest options available for as low as $124. 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.

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

    Currently, April is the cheapest month in which you can book a flight from Ontario to San Diego (average of $79). Flying from Ontario to San Diego in January 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
National City
Coronado
La Mesa
Poway
Julian
Lemon Grove

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