$63+ 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 8/22. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Aug 12 — Aug 191
Round-trip
1 adult, Economy
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Find cheap flights from Ontario to San Diego with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Ontario to San Diego
Cheapest
Best
Last-minute
One-way
Cheapest flights from Ontario to San DiegoExplore 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 July 13, 2026.
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 July 13, 2026.
This Kiwi.com deal was found by Cheapflights users on 7/13. 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 8/48:58 am
ONT
- SAN
1 stop15h 06m
Frontier
Tue 8/117:45 pm
SAN
- ONT
1 stop17h 03m
Frontier
Deal found 7/13![Frontier logo]()
$119
This Kiwi.com deal was found by Cheapflights users on 7/12. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/278:48 am
ONT
- SAN
1 stop6h 02m
Frontier
Sun 8/3010:00 am
SAN
- ONT
1 stop25h 02m
Frontier
Deal found 7/12![Frontier logo]()
$150
This Kiwi.com deal was found by Cheapflights users on 7/13. 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 8/108:58 am
ONT
- SAN
1 stop15h 01m
Frontier
Mon 8/178:51 pm
SAN
- ONT
1 stop19h 03m
Frontier
Deal found 7/13![Frontier logo]()
$156
This Kiwi.com deal was found by Cheapflights users on 7/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/104:09 pm
ONT
- SAN
1 stop3h 57m
Frontier
Tue 8/117:45 pm
SAN
- ONT
1 stop17h 03m
Frontier
Deal found 7/11![Frontier logo]()
$162
This Kiwi.com deal was found by Cheapflights users on 7/9. 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 8/68:58 am
ONT
- SAN
1 stop15h 01m
Frontier
Thu 8/137:45 pm
SAN
- ONT
1 stop15h 17m
Frontier
Deal found 7/9![Frontier logo]()
$177
Best flights from Ontario to San DiegoDiscover carefully curated flight deals from Ontario to San Diego that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 13, 2026.
Discover carefully curated flight deals from Ontario to San Diego that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 13, 2026.
This Kiwi.com deal was found by Cheapflights users on 7/13. 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 8/108:58 am
ONT
- SAN
1 stop15h 01m
Frontier
Mon 8/178:51 pm
SAN
- ONT
2 stops13h 13m
Frontier
Deal found 7/13![Frontier logo]()
$181
This Alaska Airlines deal was found by Cheapflights users on 7/11. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/14:27 pm
ONT
- SAN
1 stop4h 09m
Alaska Airlines
Sat 10/38:01 am
SAN
- ONT
1 stop9h 07m
Alaska Airlines
Deal found 7/11![Alaska Airlines logo]()
$263
This American Airlines deal was found by Cheapflights users on 7/13. 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.
Mon 8/2412:59 pm
ONT
- SAN
1 stop29h 19m
American Airlines
Thu 8/2710:57 am
SAN
- ONT
1 stop7h 18m
American Airlines
Deal found 7/13![American Airlines logo]()
$298
This Kiwi.com deal was found by Cheapflights users on 7/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/104:09 pm
ONT
- SAN
1 stop3h 57m
Frontier
Tue 8/117:45 pm
SAN
- ONT
2 stops19h 29m
Frontier
Deal found 7/11![Frontier logo]()
$237
This Kiwi.com deal was found by Cheapflights users on 7/9. 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 8/611:47 am
ONT
- SAN
2 stops12h 12m
Frontier
Thu 8/137:45 pm
SAN
- ONT
1 stop15h 17m
Frontier
Deal found 7/9![Frontier logo]()
$244
This Alaska Airlines deal was found by Cheapflights users on 7/12. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/316:02 am
ONT
- SAN
1 stop11h 50m
Alaska Airlines
Wed 11/47:54 am
SAN
- ONT
1 stop8h 38m
Alaska Airlines
Deal found 7/12![Alaska Airlines logo]()
$313
This Alaska Airlines deal was found by Cheapflights users on 7/13. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/244:27 pm
ONT
- SAN
1 stop15h 38m
Alaska Airlines
Fri 8/289:59 pm
SAN
- ONT
1 stop17h 53m
Alaska Airlines
Deal found 7/13![Alaska Airlines logo]()
$318
Last-minute flights from Ontario to San DiegoDiscover last-minute flight deals from Ontario to San Diego. Data last updated July 13, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to San Diego. Data last updated July 13, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 7/13. 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 8/48:58 am
ONT
- SAN
1 stop15h 06m
Frontier
Tue 8/117:45 pm
SAN
- ONT
1 stop17h 03m
Frontier
Deal found 7/13![Frontier logo]()
$119
This Kiwi.com deal was found by Cheapflights users on 7/9. 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 8/68:58 am
ONT
- SAN
1 stop15h 01m
Frontier
Thu 8/137:45 pm
SAN
- ONT
1 stop15h 17m
Frontier
Deal found 7/9![Frontier logo]()
$177
This Kiwi.com deal was found by Cheapflights users on 7/13. 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 8/108:58 am
ONT
- SAN
1 stop15h 01m
Frontier
Mon 8/178:51 pm
SAN
- ONT
1 stop19h 03m
Frontier
Deal found 7/13![Frontier logo]()
$156
This Kiwi.com deal was found by Cheapflights users on 7/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/104:09 pm
ONT
- SAN
1 stop3h 57m
Frontier
Tue 8/117:45 pm
SAN
- ONT
1 stop17h 03m
Frontier
Deal found 7/11![Frontier logo]()
$162
This Kiwi.com deal was found by Cheapflights users on 7/12. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/278:48 am
ONT
- SAN
1 stop6h 02m
Frontier
Sun 8/3010:00 am
SAN
- ONT
1 stop25h 02m
Frontier
Deal found 7/12![Frontier logo]()
$150
One-way flights from Ontario to San DiegoSearch for one-way flight options from Ontario to San Diego. Find affordable one-way fares based on user searches. Data last updated July 13, 2026.
Search for one-way flight options from Ontario to San Diego. Find affordable one-way fares based on user searches. Data last updated July 13, 2026.
This Kiwi.com deal was found by Cheapflights users on 7/12. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/228:48 am
ONT
- SAN
1 stop6h 02m
Frontier
Deal found 7/12![Frontier logo]()
$63
This American Airlines deal was found by Cheapflights users on 7/12. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/169:59 am
ONT
- SAN
1 stop8h 26m
American Airlines
Deal found 7/12![American Airlines logo]()
$118
This Kiwi.com deal was found by Cheapflights users on 7/12. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/169:43 pm
ONT
- SAN
2 stops21h 54m
Frontier
Deal found 7/12![Frontier logo]()
$124
This Alaska Airlines deal was found by Cheapflights users on 7/12. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/214:27 pm
ONT
- SAN
1 stop15h 38m
Alaska Airlines
Deal found 7/12![Alaska Airlines logo]()
$137
This Alaska Airlines deal was found by Cheapflights users on 7/8. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/254:27 pm
ONT
- SAN
1 stop19h 53m
Alaska Airlines
Deal found 7/8![Alaska Airlines logo]()
$144
This Alaska Airlines deal was found by Cheapflights users on 7/12. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/114:27 pm
ONT
- SAN
1 stop15h 38m
Alaska Airlines
Deal found 7/12![Alaska Airlines logo]()
$147
This Alaska Airlines deal was found by Cheapflights users on 7/9. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/165:48 pm
ONT
- SAN
1 stop14h 22m
Alaska Airlines
Deal found 7/9![Alaska Airlines logo]()
$153
This Alaska Airlines deal was found by Cheapflights users on 7/12. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/94:27 pm
ONT
- SAN
1 stop4h 09m
Alaska Airlines
Deal found 7/12![Alaska Airlines logo]()
$162
This Alaska Airlines deal was found by Cheapflights users on 7/9. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/66:31 pm
ONT
- SAN
1 stop21h 21m
Alaska Airlines
Deal found 7/9![Alaska Airlines logo]()
$163
This Alaska Airlines deal was found by Cheapflights users on 7/12. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/84:27 pm
ONT
- SAN
1 stop15h 38m
Alaska Airlines
Deal found 7/12![Alaska Airlines logo]()
$167
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 July 13, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $119 (Kiwi.com) |
One-way from | $63 (Kiwi.com) |
Popular in | January |
Cheapest in | February |
Average price | $299 |
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 July 13, 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
Cheapest round-trip
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Mon 8/10
8:58 am-11:59 pm
1 stop15h 01m
San Diego
Mon 8/17
8:51 pm-10:04 am
2 stops13h 13m
$181
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Mon 8/10
4:09 pm-8:06 pm
1 stop3h 57m
San Diego
Tue 8/11
7:45 pm-3:14 pm
2 stops19h 29m
$237
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Thu 8/6
11:47 am-11:59 pm
2 stops12h 12m
San Diego
Thu 8/13
7:45 pm-11:02 am
1 stop15h 17m
$244
Quickest round-trip
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Thu 10/1
4:27 pm-8:36 pm
1 stop4h 09m
San Diego
Sat 10/3
8:01 am-5:08 pm
1 stop9h 07m
$263
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Mon 8/24
12:59 pm-6:18 pm
1 stop29h 19m
San Diego
Thu 8/27
10:57 am-6:15 pm
1 stop7h 18m
$298
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sat 10/31
6:02 am-5:52 pm
1 stop11h 50m
San Diego
Wed 11/4
7:54 am-4:32 pm
1 stop8h 38m
$313
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Mon 8/24
4:27 pm-8:05 am
1 stop15h 38m
San Diego
Fri 8/28
9:59 pm-3:52 pm
1 stop17h 53m
$318
Cheapest one-way
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Fri 8/21
4:27 pm-12:20 pm
1 stop19h 53m
$144
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Fri 10/9
5:48 pm-8:10 am
1 stop14h 22m
$144
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Fri 9/25
4:27 pm-8:05 am
1 stop15h 38m
$144
Showing 1-10 of 19 resultsSorted by cheapest first
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 July.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- 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.
ONT-SAN
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.
Traveling to a place near San Diego?
Book flights to San Diego if you plan to visit one of these locationsEl Cajon
National City
Chula Vista
Poway
La Mesa
Coronado
Santee
San Ysidro
Julian
Lemon Grove
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