$49+ 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 12/2. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Oct 25 — Nov 11
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 September 25, 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 September 25, 2026.
This Mytrip deal was found by Cheapflights users on 9/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/512:01 pm -
1 stop6h 37m
Mon 11/910:56 am -
1 stop8h 32m
Deal found 9/20![Frontier logo]()
$123
This Kiwi.com deal was found by Cheapflights users on 9/22. 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 11/310:35 am -
2 stops8h 03m
Thu 11/510:56 am -
1 stop8h 32m
Deal found 9/22![Frontier logo]()
$134
This Mytrip deal was found by Cheapflights users on 9/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/275:07 pm -
2 stops25h 31m
Thu 10/2910:48 am -
1 stop8h 40m
Deal found 9/20![Frontier logo]()
$144
This Mytrip deal was found by Cheapflights users on 9/23. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2011:26 am -
2 stops25h 50m
Tue 10/2710:56 am -
2 stops22h 44m
Deal found 9/23![Frontier logo]()
$174
This Booking.com deal was found by Cheapflights users on 9/22. 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.
Tue 10/205:25 pm -
2 stops19h 51m
Thu 10/2910:48 am -
1 stop8h 40m
Deal found 9/22![Frontier logo]()
$175
This Mytrip deal was found by Cheapflights users on 9/21. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/410:35 am -
2 stops8h 03m
Wed 11/1110:56 am -
2 stops24h 20m
Deal found 9/21![Frontier logo]()
$177
This Mytrip deal was found by Cheapflights users on 9/22. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/710:00 am -
2 stops8h 38m
Sun 11/810:56 am -
1 stop8h 32m
Deal found 9/22![Frontier logo]()
$180
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 September 25, 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 September 25, 2026.
This Mytrip deal was found by Cheapflights users on 9/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/276:25 am -
1 stop9h 33m
Thu 10/2910:48 am -
1 stop8h 40m
Deal found 9/20![Frontier logo]()
$159
This Alaska Airlines deal was found by Cheapflights users on 9/22. 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 10/195:45 pm -
1 stop14h 25m
Wed 10/2812:48 pm -
1 stop4h 17m
Deal found 9/22![Alaska Airlines logo]()
$263
This Mytrip deal was found by Cheapflights users on 9/23. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/135:25 pm -
2 stops19h 51m
Thu 10/153:14 pm -
2 stops20h 02m
Deal found 9/23![Frontier logo]()
$184
This Booking.com deal was found by Cheapflights users on 9/22. 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.
Tue 10/206:15 am -
1 stop9h 43m
Thu 10/2910:48 am -
1 stop8h 40m
Deal found 9/22![Frontier logo]()
$202
This Frontier deal was found by Cheapflights users on 9/24. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/2912:01 pm -
1 stop6h 37m
Mon 11/210:56 am -
1 stop8h 32m
Deal found 9/24![Frontier logo]()
$203
This Alaska Airlines deal was found by Cheapflights users on 9/22. 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 10/205:45 pm -
1 stop14h 25m
Tue 10/278:01 am -
1 stop9h 04m
Deal found 9/22![Alaska Airlines logo]()
$263
This Mytrip deal was found by Cheapflights users on 9/21. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/221:38 pm -
1 stop6h 11m
Sat 10/243:14 pm -
2 stops20h 02m
Deal found 9/21![Frontier logo]()
$216
This Mytrip deal was found by Cheapflights users on 9/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/212:01 pm -
1 stop6h 37m
Sat 11/144:53 pm -
2 stops18h 23m
Deal found 9/20![Frontier logo]()
$226
This Mytrip deal was found by Cheapflights users on 9/19. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/2111:26 am -
2 stops12h 30m
Thu 10/223:14 pm -
2 stops19h 15m
Deal found 9/19![Frontier logo]()
$245
This Frontier deal was found by Cheapflights users on 9/22. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/206:15 am -
1 stop9h 43m
Thu 12/38:17 am -
1 stop10h 14m
Deal found 9/22![Frontier logo]()
$252
This Mytrip deal was found by Cheapflights users on 9/19. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/1512:01 pm -
2 stops7h 48m
Tue 10/203:14 pm -
2 stops19h 17m
Deal found 9/19![Frontier logo]()
$258
Last-minute flights from Ontario to San DiegoDiscover last-minute flight deals from Ontario to San Diego. Data last updated September 25, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to San Diego. Data last updated September 25, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 9/22. 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 10/1512:01 pm -
1 stop25h 15m
Mon 10/193:14 pm -
2 stops19h 17m
Deal found 9/22![Frontier logo]()
$191
This Mytrip deal was found by Cheapflights users on 9/23. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2011:26 am -
2 stops25h 50m
Tue 10/2710:56 am -
2 stops22h 44m
Deal found 9/23![Frontier logo]()
$174
This Booking.com deal was found by Cheapflights users on 9/22. 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.
Tue 10/205:25 pm -
2 stops19h 51m
Thu 10/2910:48 am -
1 stop8h 40m
Deal found 9/22![Frontier logo]()
$175
This Mytrip deal was found by Cheapflights users on 9/21. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:15 am -
1 stop9h 43m
Wed 10/287:33 pm -
2 stops15h 43m
Deal found 9/21![Frontier logo]()
$192
This Kiwi.com deal was found by Cheapflights users on 9/24. 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 10/228:35 pm -
2 stops41h 54m
Thu 10/2910:48 am -
1 stop8h 40m
Deal found 9/24![Frontier logo]()
$185
This Mytrip deal was found by Cheapflights users on 9/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/275:07 pm -
2 stops25h 31m
Thu 10/2910:48 am -
1 stop8h 40m
Deal found 9/20![Frontier logo]()
$144
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 September 25, 2026.
Search for one-way flight options from Ontario to San Diego. Find affordable one-way fares based on user searches. Data last updated September 25, 2026.
This Kiwi.com deal was found by Cheapflights users on 9/22. 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 12/27:26 pm -
1 stop22h 44m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$49
This Booking.com deal was found by Cheapflights users on 9/20. 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.
Mon 11/212:01 pm -
1 stop6h 37m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![Frontier logo]()
$56
This Trip.com deal was found by Cheapflights users on 9/22. 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 11/1612:01 pm -
1 stop6h 37m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$64
This Trip.com deal was found by Cheapflights users on 9/22. 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 10/2912:01 pm -
1 stop6h 37m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$74
This Trip.com deal was found by Cheapflights users on 9/22. 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 11/912:01 pm -
1 stop6h 37m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$76
This Booking.com deal was found by Cheapflights users on 9/22. 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.
Thu 11/1212:01 pm -
1 stop6h 37m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$82
This Booking.com deal was found by Cheapflights users on 9/20. 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 10/2810:35 am -
2 stops8h 03m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![Frontier logo]()
$86
This Kiwi.com deal was found by Cheapflights users on 9/22. 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 10/1311:26 am -
2 stops25h 50m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$87
This Booking.com deal was found by Cheapflights users on 9/22. 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 11/410:35 am -
2 stops8h 03m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$88
This Mytrip deal was found by Cheapflights users on 9/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/128:35 pm -
2 stops16h 41m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![Frontier logo]()
$89
This Booking.com deal was found by Cheapflights users on 9/21. 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.
Tue 11/1010:35 am -
2 stops8h 03m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$90
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 September 25, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $123 (Mytrip) |
One-way from | $49 (Kiwi.com) |
Popular in | January |
Cheapest in | February |
Average price | $269 |
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 7,457,451 searches. Data last updated September 25, 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
Thu 10/29
12:01 pm-6:38 pm
1 stop6h 37m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$87
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Mon 11/2
8:35 pm-6:38 pm
2 stops22h 03m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$93
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Sat 11/7
6:25 am-3:58 pm
1 stop9h 33m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$97
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Thu 10/22
1:38 pm-7:49 pm
1 stop6h 11m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$98
Quickest round-trip
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Thu 11/19
2:23 pm-7:47 pm
1 stop5h 24m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$98
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Wed 10/21
11:26 am-1:16 pm
2 stops25h 50m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$104
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Tue 11/3
11:52 am-11:57 pm
1 stop12h 05m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$107
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Fri 10/16
8:00 am-2:29 pm
2 stops30h 29m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$110
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Fri 10/16
5:45 pm-8:10 am
1 stop14h 25m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$137
OntarioSan Diego
ONT Ontario - SAN San Diego
ONTSAN
Ontario
Fri 10/23
5:45 pm-12:30 pm
1 stop18h 45m
San Diego
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$137
Showing 1-10 of 21 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 September.
| 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
Coronado
San Ysidro
Poway
La Mesa
Santee
Julian
Lemon Grove
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