$42+ Cheap flights from San Francisco to Ontario (SFO - ONT)
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 10/16. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ONT
Oct 21 — Oct 281
Round-trip
1 adult, Economy
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Find cheap flights from San Francisco to Ontario 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.Cheapflights Tip: The best prices from San Francisco to Ontario are usually found in August or October, booked 55 days in advance, depart on a Monday or Wednesday and return on a Friday
Cheap flight deals from San Francisco to Ontario
Cheapest
Best
Last-minute
One-way
Cheapest flights from San Francisco to OntarioExplore the most affordable flight options available from San Francisco to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 21, 2026.
Explore the most affordable flight options available from San Francisco to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 21, 2026.
This Super.com 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/166:02 pm -
Nonstop1h 38m
Mon 10/1912:01 pm -
Nonstop1h 31m
Deal found 9/19![Frontier logo]()
$64
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 11/26:02 pm -
Nonstop1h 26m
Fri 11/612:01 pm -
Nonstop1h 35m
Deal found 9/20![Frontier logo]()
$65
This Super.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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/2310:59 pm -
Nonstop1h 30m
Tue 12/17:26 pm -
Nonstop1h 34m
Deal found 9/20![Frontier logo]()
$66
This Booking.com 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/136:02 pm -
Nonstop1h 26m
Mon 11/1612:01 pm -
Nonstop1h 35m
Deal found 9/19![Frontier logo]()
$72
This Super.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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/306:02 pm -
Nonstop1h 26m
Mon 11/212:01 pm -
Nonstop1h 35m
Deal found 9/20![Frontier logo]()
$74
This Kiwi.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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/226:02 pm -
Nonstop1h 38m
Thu 10/2912:01 pm -
Nonstop1h 35m
Deal found 9/20![Frontier logo]()
$76
This Cheapflightsfares 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/19:56 pm -
Nonstop1h 23m
Wed 12/166:00 am -
1 stop16h 53m
Deal found 9/19![Frontier logo]()
$78
This Justfly.com 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/256:02 pm -
Nonstop1h 38m
Thu 10/2912:01 pm -
Nonstop1h 35m
Deal found 9/19![Frontier logo]()
$81
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.
Thu 10/226:02 pm -
Nonstop1h 38m
Fri 10/2312:01 pm -
Nonstop1h 31m
Deal found 9/20![Frontier logo]()
$82
This Cheapflightsfares deal was found by Cheapflights users on 9/18. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/156:02 pm -
Nonstop1h 38m
Mon 10/198:35 pm -
1 stop11h 38m
Deal found 9/18![Frontier logo]()
$83
Best flights from San Francisco to OntarioDiscover carefully curated flight deals from San Francisco to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 21, 2026.
Discover carefully curated flight deals from San Francisco to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 21, 2026.
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/1011:00 am -
Nonstop1h 29m
Sun 11/156:00 am -
Nonstop1h 30m
Deal found 9/19![United Airlines logo]()
$138
This Southwest deal was found by Cheapflights users on 9/17. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:55 am -
1 stop3h 50m
Tue 10/275:00 pm -
1 stop5h 50m
Deal found 9/17![Southwest logo]()
$141
This United Airlines deal was found by Cheapflights users on 9/18. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/69:20 pm -
Nonstop1h 28m
Sat 11/71:35 pm -
Nonstop1h 30m
Deal found 9/18![United Airlines logo]()
$138
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/105:00 am -
1 stop3h 45m
Wed 10/145:00 pm -
1 stop5h 50m
Deal found 9/20![Southwest logo]()
$170
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/65:15 am -
1 stop5h 35m
Wed 11/1112:50 pm -
2 stops7h 20m
Deal found 9/20![Southwest logo]()
$170
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/511:00 am -
Nonstop1h 29m
Mon 11/91:35 pm -
Nonstop1h 30m
Deal found 9/20![United Airlines logo]()
$207
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/127:00 pm -
Nonstop1h 31m
Sat 10/174:03 pm -
Nonstop1h 47m
Deal found 9/20![United Airlines logo]()
$207
This Southwest deal was found by Cheapflights users on 9/16. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:55 am -
2 stops8h 40m
Wed 10/216:10 am -
2 stops9h 00m
Deal found 9/16![Southwest logo]()
$222
This United Airlines deal was found by Cheapflights users on 9/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/249:25 pm -
Nonstop1h 26m
Sun 10/256:00 am -
Nonstop1h 30m
Deal found 9/17![United Airlines logo]()
$209
This Southwest deal was found by Cheapflights users on 9/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/134:15 pm -
1 stop6h 45m
Sun 11/155:20 pm -
1 stop6h 20m
Deal found 9/18![Southwest logo]()
$278
Last-minute flights from San Francisco to OntarioDiscover last-minute flight deals from San Francisco to Ontario. Data last updated September 21, 2026 and is based on user searches.
Discover last-minute flight deals from San Francisco to Ontario. Data last updated September 21, 2026 and is based on user searches.
This Kissandfly.com deal was found by Cheapflights users on 9/18. 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 Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/269:25 pm -
Nonstop1h 34m
Mon 9/2812:07 pm -
Nonstop1h 36m
Deal found 9/18![Frontier logo]()
$175
This Booking.com 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/276:02 pm -
Nonstop1h 34m
Mon 9/2812:07 pm -
Nonstop1h 36m
Deal found 9/19![Frontier logo]()
$190
This FlightHub deal was found by Cheapflights users on 9/17. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/286:02 pm -
Nonstop1h 34m
Mon 10/512:07 pm -
Nonstop1h 36m
Deal found 9/17![Frontier logo]()
$171
This Super.com deal was found by Cheapflights users on 9/17. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/286:02 pm -
Nonstop1h 34m
Thu 10/812:01 pm -
Nonstop1h 31m
Deal found 9/17![Frontier logo]()
$182
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.
Thu 10/16:02 pm -
Nonstop1h 34m
Fri 10/212:07 pm -
Nonstop1h 36m
Deal found 9/20![Frontier logo]()
$98
This Super.com deal was found by Cheapflights users on 9/18. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:02 pm -
Nonstop1h 34m
Sun 10/1112:01 pm -
Nonstop1h 31m
Deal found 9/18![Frontier logo]()
$121
This Super.com deal was found by Cheapflights users on 9/18. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:02 pm -
Nonstop1h 34m
Sun 10/412:07 pm -
Nonstop1h 36m
Deal found 9/18![Frontier logo]()
$156
This Cheapflightsfares deal was found by Cheapflights users on 9/18. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:02 pm -
Nonstop1h 34m
Mon 10/58:24 pm -
1 stop22h 00m
Deal found 9/18![Frontier logo]()
$186
This Cheapflightsfares 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:02 pm -
Nonstop1h 34m
Sat 10/36:15 am -
1 stop17h 59m
Deal found 9/20![Frontier logo]()
$191
One-way flights from San Francisco to OntarioSearch for one-way flight options from San Francisco to Ontario. Find affordable one-way fares based on user searches. Data last updated September 21, 2026.
Search for one-way flight options from San Francisco to Ontario. Find affordable one-way fares based on user searches. Data last updated September 21, 2026.
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.
Fri 10/166:02 pm -
Nonstop1h 38m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$42
This Trip.com deal was found by Cheapflights users on 9/18. 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 12/49:56 pm -
Nonstop1h 23m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$43
This FlightHub deal was found by Cheapflights users on 9/18. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/2710:59 pm -
Nonstop1h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$44
This Trip.com deal was found by Cheapflights users on 9/18. 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.
Sat 12/129:56 pm -
Nonstop1h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$45
This FlightHub deal was found by Cheapflights users on 9/18. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/59:56 pm -
Nonstop1h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$46
This Super.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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:02 pm -
Nonstop1h 34m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$48
This Cheapflightsfares deal was found by Cheapflights users on 9/18. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/306:02 pm -
Nonstop1h 26m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$51
This Trip.com deal was found by Cheapflights users on 9/16. 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 12/169:56 pm -
Nonstop1h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/16![Frontier logo]()
$52
This Super.com deal was found by Cheapflights users on 9/18. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/86:02 pm -
Nonstop1h 26m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$53
This Super.com deal was found by Cheapflights users on 9/18. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/156:02 pm -
Nonstop1h 26m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$54
Find flight deals from San Francisco to Ontario
Discover tips and strategies to find the most affordable flight options for your journey from San Francisco (SFO) to Ontario (ONT). 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 21, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $64 (Super.com) |
One-way from | $42 (Booking.com) |
Popular in | February |
Cheapest in | August |
Average price | $186 |
Good round-trip deal | $116 or less |
Good one-way deal | $62 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from San Francisco to Ontario 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 21, 2026.
Use the filters below to find and compare flights from San Francisco to Ontario that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Fri 11/13
4:15 pm-11:00 pm
1 stop6h 45m
Ontario
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$90
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Fri 10/16
10:45 pm-8:45 am
1 stop10h 00m
Ontario
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$101
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Sat 11/7
11:00 am-12:29 pm
Nonstop1h 29m
Ontario
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$104
Quickest round-trip
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Mon 10/12
9:25 pm-10:51 pm
Nonstop1h 26m
Ontario
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$104
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Thu 11/5
11:00 am-12:29 pm
Nonstop1h 29m
Ontario
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$104
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Sun 10/11
7:00 pm-8:31 pm
Nonstop1h 31m
Ontario
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$119
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Fri 11/6
9:20 pm-10:48 pm
Nonstop1h 28m
Ontario
Wed 12/31
12:00 am-12:00 am
Nonstop0h 00m
$131
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Tue 11/10
11:00 am-12:29 pm
Nonstop1h 29m
Ontario
Sun 11/15
6:00 am-7:30 am
Nonstop1h 30m
$138
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Fri 11/6
9:20 pm-10:48 pm
Nonstop1h 28m
Ontario
Sat 11/7
1:35 pm-3:05 pm
Nonstop1h 30m
$138
San FranciscoOntario
SFO San Francisco - ONT Ontario
SFOONT
San Francisco
Wed 10/21
6:55 am-10:45 am
1 stop3h 50m
Ontario
Tue 10/27
5:00 pm-10:50 pm
1 stop5h 50m
$141
Showing 1-10 of 22 resultsSorted by cheapest first
Compare providers for flights from San Francisco to Ontario
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 San Francisco to Ontario in September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy1 star | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on San Francisco-Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on San Francisco-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from San Francisco-Ontario flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on San Francisco-Ontario 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 San Francisco-Ontario 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 San Francisco to Ontario
Have a flexible travel schedule? Discover the best time to fly to Ontario from San Francisco with our price prediction graph.
SFO-ONT
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 San Francisco to Ontario
Prices
Delays
How far ahead should I book a flight from San Francisco to Ontario?
Booking 54 days in advance of your planned departure date is, on average, the best time to get cheap flights from San Francisco to Ontario. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
What is the cheapest month to book a flight from San Francisco to Ontario?
Currently, August is the cheapest month in which you can book a flight from San Francisco to Ontario (average of $171). Flying from San Francisco to Ontario in February is currently the most expensive (average of $317). 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.
What is the cheapest time of day to fly from SFO to ONT?
Find hourly flight availability from San Francisco to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 21, 2026.
Unlike in the afternoon, when flights are generally more expensive, you can save up to 28% on flights from San Francisco to Ontario by exploring options for tickets in the evening.
What is the cheapest day to fly from San Francisco to Ontario?
Use this chart to determine the cheapest time to fly round-trip from San Francisco to Ontario. Price data was last updated on September 19, 2026.
Travelers seeking maximum savings on their San Francisco to Ontario flight should consider departing on Monday evenings when fares are most often at their lowest. Monday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
How often are flights from San Francisco to Ontario delayed?
About 16% of weekly flights between San Francisco and Ontario have experienced delays in the past year, with the average delay time being 112 minutes.
What is the most punctual flight time for San Francisco to Ontario flights?
Historically, flights departing in the evening are less likely to be delayed, whereas flights leaving at night tend to experience delays more often.
What day of the week experiences the fewest flight delays on this route?
Saturday tends to have the lowest number of delays on this route, whereas Thursday has historically faced a higher average of delays compared to other days of the week.
Which airline has the best punctuality record on San Francisco to Ontario flights?
Over the last year, United Airlines have had the lowest number of delays on this route, with just 14% of flights being delayed.
The best insider tips for San Francisco to Ontario flights
AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your San Francisco to Ontario trip
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Reviews of airlines servicing Ontario
Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated September 21, 2026.
Peruse reviews from past customers who have flown with Alaska Airlines,Delta, andUnited Airlines from San Francisco to Ontario to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Comfort
7.8
Entertainment
7.0
Food
7.0
Boarding
8.1
Crew
8.5
Overall
7.9
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Comfort
7.8
Entertainment
7.0
Food
7.0
Boarding
8.1
Crew
8.5
Overall
7.9
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Comfort
7.8
Entertainment
7.0
Food
7.0
Boarding
8.1
Crew
8.5
Overall
7.9
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Comfort
7.8
Entertainment
7.0
Food
7.0
Boarding
8.1
Crew
8.5
Overall
7.9
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Comfort
7.8
Entertainment
7.0
Food
7.0
Boarding
8.1
Crew
8.5
Overall
7.9
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Comfort
7.8
Entertainment
7.0
Food
7.0
Boarding
8.1
Crew
8.5
Overall
7.9
Reviews
1 / 20
10.0
ExcellentFranzi,Mar 2026
SFO - PDX
Related info for your journey
Find useful and relevant information for your journey from San Francisco to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Alternative routes for San Francisco to Ontario
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Complete your trip
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Other flights to Ontario
Explore flights to Ontario departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 21, 2026.
San Francisco and Ontario flights
Browse other San Francisco and Ontario flight options. Last updated on September 21, 2026.
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Browse through other flights departing from San Francisco. Flights are based on user searches made on Cheapflights and were last updated on September 21, 2026.
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Check out other popular destinations found by fellow travelers in 2026
Top 6 airlines flying from San Francisco to Ontario
Discover the top 6 airlines that operate flights from San Francisco to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated September 21, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$54 | Average$160 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$97 | Average$313 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$98 | Average$227 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$117 | Average$258 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$142 | Average$302 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$212 | Average$246 | FlexibilityNo cancel fee | On-time63% |