$126+ Cheap flights from Ontario to San Diego (ONT - SAN)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 6/2. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Jun 11 — Jun 181
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 May 12, 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 May 12, 2026.
This Kiwi.com deal was found by Cheapflights users on 5/7. 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.
Tue 6/24:39 pm
ONT
- SAN
1 stop16h 08m
Frontier
Thu 6/49:43 am
SAN
- ONT
1 stop5h 26m
Frontier
Deal found 5/7![Frontier logo]()
$126
This Kiwi.com deal was found by Cheapflights users on 5/7. 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.
Tue 6/93:34 pm
ONT
- SAN
1 stop17h 14m
Frontier
Mon 6/159:43 am
SAN
- ONT
1 stop23h 24m
Frontier
Deal found 5/7![Frontier logo]()
$132
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/173:34 pm
ONT
- SAN
1 stop17h 14m
Frontier
Mon 6/229:43 am
SAN
- ONT
1 stop5h 25m
Frontier
Deal found 5/10![Frontier logo]()
$187
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 6/63:30 pm
ONT
- SAN
1 stop17h 17m
Frontier
Sat 6/139:43 am
SAN
- ONT
1 stop5h 25m
Frontier
Deal found 5/8![Frontier logo]()
$211
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 6/253:34 pm
ONT
- SAN
1 stop17h 14m
Frontier
Tue 6/309:43 am
SAN
- ONT
1 stop10h 08m
Frontier
Deal found 5/8![Frontier logo]()
$256
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/293:40 pm
ONT
- SAN
1 stop5h 18m
Frontier
Sat 8/18:29 pm
SAN
- ONT
1 stop23h 24m
Frontier
Deal found 5/10![Frontier logo]()
$265
This Kiwi.com deal was found by Cheapflights users on 5/11. 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.
Sun 6/213:34 pm
ONT
- SAN
1 stop17h 14m
Frontier
Thu 6/259:43 am
SAN
- ONT
1 stop5h 25m
Frontier
Deal found 5/11![Frontier logo]()
$267
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 May 12, 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 May 12, 2026.
This Alaska Airlines deal was found by Cheapflights users on 5/9. 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.
Sat 5/303:35 pm
ONT
- SAN
1 stop5h 52m
Alaska Airlines
Mon 6/112:12 pm
SAN
- ONT
1 stop6h 56m
Alaska Airlines
Deal found 5/9![Alaska Airlines logo]()
$358
This American Airlines deal was found by Cheapflights users on 5/10. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 6/287:13 pm
ONT
- SAN
1 stop37h 46m
American Airlines
Wed 7/17:15 pm
SAN
- ONT
1 stop26h 29m
American Airlines
Deal found 5/10![American Airlines logo]()
$424
This Alaska Airlines deal was found by Cheapflights users on 5/9. 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.
Mon 6/156:43 pm
ONT
- SAN
1 stop13h 32m
Alaska Airlines
Tue 6/238:24 am
SAN
- ONT
1 stop9h 39m
Alaska Airlines
Deal found 5/9![Alaska Airlines logo]()
$413
This Alaska Airlines deal was found by Cheapflights users on 5/9. 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.
Sat 5/303:35 pm
ONT
- SAN
1 stop5h 52m
Alaska Airlines
Sun 5/316:15 am
SAN
- ONT
1 stop8h 54m
Alaska Airlines
Deal found 5/9![Alaska Airlines logo]()
$443
This Alaska Airlines deal was found by Cheapflights users on 5/7. 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.
Mon 7/136:43 pm
ONT
- SAN
1 stop18h 07m
Alaska Airlines
Tue 8/48:24 am
SAN
- ONT
1 stop9h 39m
Alaska Airlines
Deal found 5/7![Alaska Airlines logo]()
$457
This Alaska Airlines deal was found by Cheapflights users on 5/8. 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.
Sat 6/63:35 pm
ONT
- SAN
1 stop5h 52m
Alaska Airlines
Mon 6/89:27 am
SAN
- ONT
1 stop9h 41m
Alaska Airlines
Deal found 5/8![Alaska Airlines logo]()
$467
This Alaska Airlines deal was found by Cheapflights users on 5/7. 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.
Sun 7/126:43 pm
ONT
- SAN
1 stop13h 32m
Alaska Airlines
Tue 8/48:24 am
SAN
- ONT
1 stop9h 39m
Alaska Airlines
Deal found 5/7![Alaska Airlines logo]()
$470
This Alaska Airlines deal was found by Cheapflights users on 5/7. 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.
Sun 7/126:43 pm
ONT
- SAN
1 stop13h 32m
Alaska Airlines
Wed 8/58:24 am
SAN
- ONT
1 stop9h 39m
Alaska Airlines
Deal found 5/7![Alaska Airlines logo]()
$470
This Alaska Airlines deal was found by Cheapflights users on 5/10. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/303:35 pm
ONT
- SAN
1 stop17h 15m
Alaska Airlines
Wed 6/39:27 am
SAN
- ONT
1 stop9h 41m
Alaska Airlines
Deal found 5/10![Alaska Airlines logo]()
$473
This Alaska Airlines deal was found by Cheapflights users on 5/10. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 7/266:43 pm
ONT
- SAN
1 stop13h 32m
Alaska Airlines
Sun 8/29:16 pm
SAN
- ONT
1 stop12h 40m
Alaska Airlines
Deal found 5/10![Alaska Airlines logo]()
$515
This Alaska Airlines deal was found by Cheapflights users on 5/9. 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 6/196:43 pm
ONT
- SAN
1 stop13h 32m
Alaska Airlines
Mon 6/228:24 am
SAN
- ONT
1 stop9h 39m
Alaska Airlines
Deal found 5/9![Alaska Airlines logo]()
$518
Last-minute flights from Ontario to San DiegoDiscover last-minute flight deals from Ontario to San Diego. Data last updated May 12, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to San Diego. Data last updated May 12, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 5/7. 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.
Tue 6/24:39 pm
ONT
- SAN
1 stop16h 08m
Frontier
Thu 6/49:43 am
SAN
- ONT
1 stop5h 26m
Frontier
Deal found 5/7![Frontier logo]()
$126
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 6/63:30 pm
ONT
- SAN
1 stop17h 17m
Frontier
Sat 6/139:43 am
SAN
- ONT
1 stop5h 25m
Frontier
Deal found 5/8![Frontier logo]()
$211
This Kiwi.com deal was found by Cheapflights users on 5/7. 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.
Tue 6/93:34 pm
ONT
- SAN
1 stop17h 14m
Frontier
Mon 6/159:43 am
SAN
- ONT
1 stop23h 24m
Frontier
Deal found 5/7![Frontier logo]()
$132
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/173:34 pm
ONT
- SAN
1 stop17h 14m
Frontier
Mon 6/229:43 am
SAN
- ONT
1 stop5h 25m
Frontier
Deal found 5/10![Frontier logo]()
$187
This Kiwi.com deal was found by Cheapflights users on 5/11. 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.
Sun 6/213:34 pm
ONT
- SAN
1 stop17h 14m
Frontier
Thu 6/259:43 am
SAN
- ONT
1 stop5h 25m
Frontier
Deal found 5/11![Frontier logo]()
$267
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 6/253:34 pm
ONT
- SAN
1 stop17h 14m
Frontier
Tue 6/309:43 am
SAN
- ONT
1 stop10h 08m
Frontier
Deal found 5/8![Frontier logo]()
$256
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 May 12, 2026.
Search for one-way flight options from Ontario to San Diego. Find affordable one-way fares based on user searches. Data last updated May 12, 2026.
This American Airlines deal was found by Cheapflights users on 5/7. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/21:10 pm
ONT
- SAN
1 stop8h 24m
American Airlines
Deal found 5/7![American Airlines logo]()
$139
This Kiwi.com deal was found by Cheapflights users on 5/11. 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.
Wed 5/274:39 pm
ONT
- SAN
1 stop4h 33m
Frontier
Deal found 5/11![Frontier logo]()
$150
This Alaska Airlines deal was found by Cheapflights users on 5/8. 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.
Tue 6/93:35 pm
ONT
- SAN
1 stop5h 52m
Alaska Airlines
Deal found 5/8![Alaska Airlines logo]()
$187
This Kiwi.com deal was found by Cheapflights users on 5/11. 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.
Fri 5/298:59 am
ONT
- SAN
2 stops36h 13m
Frontier
Deal found 5/11![Frontier logo]()
$192
This Alaska Airlines deal was found by Cheapflights users on 5/10. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/196:43 pm
ONT
- SAN
1 stop13h 32m
Alaska Airlines
Deal found 5/10![Alaska Airlines logo]()
$212
This Alaska Airlines deal was found by Cheapflights users on 5/11. 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.
Mon 6/13:35 pm
ONT
- SAN
1 stop17h 15m
Alaska Airlines
Deal found 5/11![Alaska Airlines logo]()
$214
This Alaska Airlines deal was found by Cheapflights users on 5/11. 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.
Fri 6/57:41 pm
ONT
- SAN
1 stop16h 10m
Alaska Airlines
Deal found 5/11![Alaska Airlines logo]()
$217
This Kiwi.com deal was found by Cheapflights users on 5/11. 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.
Thu 5/283:30 pm
ONT
- SAN
1 stop5h 42m
Frontier
Deal found 5/11![Frontier logo]()
$218
This Alaska Airlines deal was found by Cheapflights users on 5/8. 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 8/284:18 pm
ONT
- SAN
1 stop20h 02m
Alaska Airlines
Deal found 5/8![Alaska Airlines logo]()
$231
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 May 12, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $126 (Kiwi.com) |
Popular in | January |
Cheapest in | February |
Average price | $239 |
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 May 12, 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
Quickest round-trip
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sat 5/30
3:35 pm-9:27 pm
1 stop5h 52m
San Diego
Mon 6/1
12:12 pm-7:08 pm
1 stop6h 56m
$358
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Mon 6/15
6:43 pm-8:15 am
1 stop13h 32m
San Diego
Tue 6/23
8:24 am-6:03 pm
1 stop9h 39m
$413
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sun 6/28
7:13 pm-8:59 am
1 stop37h 46m
San Diego
Wed 7/1
7:15 pm-9:44 pm
1 stop26h 29m
$424
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sat 5/30
3:35 pm-9:27 pm
1 stop5h 52m
San Diego
Sun 5/31
6:15 am-3:09 pm
1 stop8h 54m
$443
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Mon 7/13
6:43 pm-12:50 pm
1 stop18h 07m
San Diego
Tue 8/4
8:24 am-6:03 pm
1 stop9h 39m
$457
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sat 6/6
3:35 pm-9:27 pm
1 stop5h 52m
San Diego
Mon 6/8
9:27 am-7:08 pm
1 stop9h 41m
$467
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sun 7/12
6:43 pm-8:15 am
1 stop13h 32m
San Diego
Tue 8/4
8:24 am-6:03 pm
1 stop9h 39m
$470
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sun 7/12
6:43 pm-8:15 am
1 stop13h 32m
San Diego
Wed 8/5
8:24 am-6:03 pm
1 stop9h 39m
$470
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sat 5/30
3:35 pm-8:50 am
1 stop17h 15m
San Diego
Wed 6/3
9:27 am-7:08 pm
1 stop9h 41m
$473
OntarioSan Diego
ONT - SAN
ONTSAN
Ontario
Sun 7/26
6:43 pm-8:15 am
1 stop13h 32m
San Diego
Sun 8/2
9:16 pm-9:56 am
1 stop12h 40m
$515
Showing 1-10 of 23 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 May.
| 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
Chula Vista
National City
Coronado
La Mesa
Poway
Julian
Lemon Grove
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