$57+ 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 9/10. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Sep 9 — Sep 161
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
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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 August 10, 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 August 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 9/116:15 am -
1 stop17h 36m
Mon 9/1410:28 am -
1 stop9h 08m
Deal found 8/8![Frontier logo]()
$135
This Kiwi.com deal was found by Cheapflights users on 8/6. 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.
Mon 9/212:30 pm -
1 stop5h 47m
Wed 9/235:54 pm -
1 stop13h 10m
Deal found 8/6![Frontier logo]()
$191
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 9/57:56 pm -
1 stop13h 09m
Sat 9/125:54 pm -
1 stop13h 10m
Deal found 8/8![Frontier logo]()
$204
This Kiwi.com deal was found by Cheapflights users on 8/9. 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.
Sun 9/68:48 am -
1 stop6h 02m
Sun 9/139:03 pm -
1 stop10h 01m
Deal found 8/9![Frontier logo]()
$214
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 11/74:27 pm -
2 stops40h 35m
Sun 11/154:36 pm -
1 stop21h 04m
Deal found 8/8![Frontier logo]()
$216
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 9/1910:04 am -
1 stop6h 55m
Mon 9/219:03 pm -
1 stop12h 06m
Deal found 8/6![Frontier logo]()
$227
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 August 10, 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 August 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 8/5. 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.
Fri 9/118:00 am -
2 stops10h 19m
Mon 9/1410:28 am -
1 stop9h 08m
Deal found 8/5![Frontier logo]()
$240
This Alaska Airlines deal was found by Cheapflights users on 8/5. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/94:27 pm -
1 stop4h 09m
Wed 9/169:59 pm -
1 stop17h 48m
Deal found 8/5![Alaska Airlines logo]()
$263
This Alaska Airlines deal was found by Cheapflights users on 8/7. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/294:27 pm -
1 stop19h 53m
Sat 10/312:48 pm -
1 stop4h 17m
Deal found 8/7![Alaska Airlines logo]()
$263
This Booking.com deal was found by Cheapflights users on 8/10. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/94:27 pm -
1 stop4h 09m
Tue 9/157:57 am -
1 stop7h 50m
Deal found 8/10![Alaska Airlines logo]()
$283
This flugladen.de deal was found by Cheapflights users on 8/9. 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 flugladen.de is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/34:27 pm -
1 stop4h 09m
Sun 9/67:57 am -
1 stop7h 50m
Deal found 8/9![Alaska Airlines logo]()
$286
This Alaska Airlines deal was found by Cheapflights users on 8/6. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/305:45 pm -
1 stop18h 45m
Mon 11/27:54 am -
1 stop8h 38m
Deal found 8/6![Alaska Airlines logo]()
$303
This Booking.com deal was found by Cheapflights users on 8/10. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/44:27 pm -
1 stop15h 38m
Sun 9/67:57 am -
1 stop7h 50m
Deal found 8/10![Alaska Airlines logo]()
$323
This Booking.com deal was found by Cheapflights users on 8/5. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/254:27 pm -
1 stop15h 38m
Sun 9/277:57 am -
1 stop7h 50m
Deal found 8/5![Alaska Airlines logo]()
$333
This Alaska Airlines deal was found by Cheapflights users on 8/6. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/24:27 pm -
1 stop4h 09m
Sat 9/57:57 am -
1 stop7h 55m
Deal found 8/6![Alaska Airlines logo]()
$350
This Alaska Airlines deal was found by Cheapflights users on 8/6. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/194:27 pm -
1 stop15h 38m
Sun 9/209:59 pm -
1 stop17h 48m
Deal found 8/6![Alaska Airlines logo]()
$353
This Alaska Airlines deal was found by Cheapflights users on 8/9. 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 10/95:45 pm -
1 stop14h 25m
Mon 10/128:01 am -
1 stop9h 04m
Deal found 8/9![Alaska Airlines logo]()
$373
Last-minute flights from Ontario to San DiegoDiscover last-minute flight deals from Ontario to San Diego. Data last updated August 10, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to San Diego. Data last updated August 10, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 9/57:56 pm -
1 stop13h 09m
Sat 9/125:54 pm -
1 stop13h 10m
Deal found 8/8![Frontier logo]()
$204
This Kiwi.com deal was found by Cheapflights users on 8/9. 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.
Sun 9/68:48 am -
1 stop6h 02m
Sun 9/139:03 pm -
1 stop10h 01m
Deal found 8/9![Frontier logo]()
$214
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 9/116:15 am -
1 stop17h 36m
Mon 9/1410:28 am -
1 stop9h 08m
Deal found 8/8![Frontier logo]()
$135
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 9/1910:04 am -
1 stop6h 55m
Mon 9/219:03 pm -
1 stop12h 06m
Deal found 8/6![Frontier logo]()
$227
This Kiwi.com deal was found by Cheapflights users on 8/6. 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.
Mon 9/212:30 pm -
1 stop5h 47m
Wed 9/235:54 pm -
1 stop13h 10m
Deal found 8/6![Frontier logo]()
$191
This Kiwi.com deal was found by Cheapflights users on 8/7. 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 9/258:24 pm -
1 stop20h 35m
Fri 10/99:43 pm -
1 stop12h 38m
Deal found 8/7![Frontier logo]()
$239
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 August 10, 2026.
Search for one-way flight options from Ontario to San Diego. Find affordable one-way fares based on user searches. Data last updated August 10, 2026.
This Trip.com deal was found by Cheapflights users on 8/5. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1012:07 pm -
1 stop6h 12m
Deal found 8/5![Frontier logo]()
$57
This Trip.com deal was found by Cheapflights users on 8/8. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/2812:07 pm -
1 stop6h 12m
Deal found 8/8![Frontier logo]()
$58
This Trip.com deal was found by Cheapflights users on 8/7. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/68:48 am -
1 stop6h 02m
Deal found 8/7![Frontier logo]()
$65
This Trip.com deal was found by Cheapflights users on 8/7. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/1412:07 pm -
1 stop6h 12m
Deal found 8/7![Frontier logo]()
$81
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 10/1511:38 am -
1 stop7h 59m
Deal found 8/8![Frontier logo]()
$86
This Trip.com deal was found by Cheapflights users on 8/6. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/302:58 pm -
1 stop4h 55m
Deal found 8/6![Frontier logo]()
$93
This Trip.com deal was found by Cheapflights users on 8/6. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/1610:04 am -
1 stop6h 55m
Deal found 8/6![Frontier logo]()
$94
This Trip.com deal was found by Cheapflights users on 8/6. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/2310:04 am -
1 stop6h 55m
Deal found 8/6![Frontier logo]()
$95
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 10/1411:16 am -
1 stop22h 04m
Deal found 8/8![Frontier logo]()
$97
This Kiwi.com deal was found by Cheapflights users on 8/8. 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.
Sun 10/119:12 pm -
1 stop23h 36m
Deal found 8/8![Frontier logo]()
$99
This Trip.com deal was found by Cheapflights users on 8/6. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/172:30 pm -
1 stop5h 47m
Deal found 8/6![Frontier logo]()
$100
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 10/1311:16 am -
2 stops25h 24m
Deal found 8/8![Frontier logo]()
$104
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 August 10, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $135 (Kiwi.com) |
One-way from | $57 (Trip.com) |
Popular in | January |
Cheapest in | February |
Average price | $284 |
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 August 10, 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 Ontario - SAN San Diego
ONTSAN
Ontario
Fri 9/11
8:00 am-6:19 pm
2 stops10h 19m
San Diego
Mon 9/14
10:28 am-7:36 pm
1 stop9h 08m
$240
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Wed 9/9
4:27 pm-8:36 pm
1 stop4h 09m
San Diego
Wed 9/16
9:59 pm-3:47 pm
1 stop17h 48m
$263
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Tue 9/29
4:27 pm-12:20 pm
1 stop19h 53m
San Diego
Sat 10/3
12:48 pm-5:05 pm
1 stop4h 17m
$263
Quickest round-trip
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Wed 9/9
4:27 pm-8:36 pm
1 stop4h 09m
San Diego
Tue 9/15
7:57 am-3:47 pm
1 stop7h 50m
$283
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Thu 9/3
4:27 pm-8:36 pm
1 stop4h 09m
San Diego
Sun 9/6
7:57 am-3:47 pm
1 stop7h 50m
$286
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Fri 10/30
5:45 pm-12:30 pm
1 stop18h 45m
San Diego
Mon 11/2
7:54 am-4:32 pm
1 stop8h 38m
$303
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Fri 9/4
4:27 pm-8:05 am
1 stop15h 38m
San Diego
Sun 9/6
7:57 am-3:47 pm
1 stop7h 50m
$323
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Fri 9/25
4:27 pm-8:05 am
1 stop15h 38m
San Diego
Sun 9/27
7:57 am-3:47 pm
1 stop7h 50m
$333
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Wed 9/2
4:27 pm-8:36 pm
1 stop4h 09m
San Diego
Sat 9/5
7:57 am-3:52 pm
1 stop7h 55m
$350
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Sat 9/19
4:27 pm-8:05 am
1 stop15h 38m
San Diego
Sun 9/20
9:59 pm-3:47 pm
1 stop17h 48m
$353
Showing 1-10 of 20 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 August.
| 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
Coronado
San Ysidro
La Mesa
Santee
Julian
Lemon Grove
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