Save time by using the SFO2Go program to order meals for pickup during busy times.
$41+ Cheap flights from San Francisco to Ontario (SFO - ONT)
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 10/26. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ONT
Aug 26 — Sep 21
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 February or October, booked 89 days in advance, depart on a Monday or Saturday and return on a Friday
Cheap 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 August 21, 2025.
Round-trip from | $68 (Cheapflightsfares) |
|---|---|
One-way from | $41 (Priceline) |
Popular in | December |
Cheapest in | February |
Average price | $140 |
Good round-trip deal | $91 or less |
Good one-way deal | $61 or less |
Find flight deals from San Francisco to Ontario
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 August 21, 2025.
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 August 21, 2025.
This Cheapflightsfares deal was found by Cheapflights users on 8/21. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/1210:11 pmSFO - ONT
Nonstop1h 27mFrontier
Sun 9/1410:13 pmONT - SFO
Nonstop1h 35mFrontier
Deal found 8/21![Frontier logo]()
$68
This Frontier deal was found by Cheapflights users on 8/20. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/410:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 9/89:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/20![Frontier logo]()
$69
This Frontier deal was found by Cheapflights users on 8/21. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/310:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 10/69:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/21![Frontier logo]()
$70
This Frontier deal was found by Cheapflights users on 8/20. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/1510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 9/229:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/20![Frontier logo]()
$71
This Cheapflightsfares deal was found by Cheapflights users on 8/21. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 9/89:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/21![Frontier logo]()
$72
This Cheapflightsfares deal was found by Cheapflights users on 8/21. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/710:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 9/89:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/21![Frontier logo]()
$73
This Gotogate deal was found by Cheapflights users on 8/20. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 9/299:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/20![Frontier logo]()
$74
This Cheapflightsfares deal was found by Cheapflights users on 8/19. 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.
Thu 9/2510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Sun 9/2810:13 pmONT - SFO
Nonstop1h 35mFrontier
Deal found 8/19![Frontier logo]()
$75
This Cheapflightsfares deal was found by Cheapflights users on 8/21. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/1010:38 pmSFO - ONT
Nonstop1h 29mFrontier
Mon 10/1310:50 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/21![Frontier logo]()
$76
This Cheapflightsfares deal was found by Cheapflights users on 8/21. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Sun 9/710:13 pmONT - SFO
Nonstop1h 35mFrontier
Deal found 8/21![Frontier logo]()
$77
This Frontier deal was found by Cheapflights users on 8/20. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/410:11 pmSFO - ONT
Nonstop1h 27mFrontier
Thu 9/189:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/20![Frontier logo]()
$78
This Cheapflightsfares deal was found by Cheapflights users on 8/19. 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.
Thu 9/410:11 pmSFO - ONT
Nonstop1h 27mFrontier
Thu 9/119:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 8/19![Frontier logo]()
$79
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 2,558,603 searches. Data last updated August 21, 2025.
Use the filters below to find and compare flights from San Francisco to Ontario that are best for you.
Fly from
San Francisco
Fly to
Ontario
Route
Depart
Return
Price
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Thu 9/25
10:11 pm-11:38 pm
Nonstop1h 27m
Ontario
Sun 9/28
10:13 pm-11:48 pm
Nonstop1h 35m
$68
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Fri 10/3
10:11 pm-11:38 pm
Nonstop1h 27m
Ontario
Mon 10/6
9:46 pm-11:15 pm
Nonstop1h 29m
$70
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Sat 10/4
4:29 pm-5:49 pm
Nonstop1h 20m
Ontario
Sat 10/4
6:51 pm-8:10 pm
Nonstop1h 19m
$72
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Fri 9/5
10:11 pm-11:38 pm
Nonstop1h 27m
Ontario
Mon 9/8
9:46 pm-11:15 pm
Nonstop1h 29m
$72
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Mon 9/29
10:11 pm-11:38 pm
Nonstop1h 27m
Ontario
Thu 10/2
9:46 pm-11:15 pm
Nonstop1h 29m
$74
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Fri 11/7
10:11 pm-11:40 pm
Nonstop1h 29m
Ontario
Sun 11/9
10:50 pm-12:19 am
Nonstop1h 29m
$76
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Sat 11/8
9:30 pm-10:51 pm
Nonstop1h 21m
Ontario
Wed 11/12
6:38 pm-8:02 pm
Nonstop1h 24m
$77
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Wed 10/29
9:30 pm-10:51 pm
Nonstop1h 21m
Ontario
Sat 11/1
6:38 pm-8:02 pm
Nonstop1h 24m
$77
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Mon 10/20
10:38 pm-12:07 am
Nonstop1h 29m
Ontario
Thu 10/23
10:40 pm-12:09 am
Nonstop1h 29m
$77
San FranciscoOntario
SFO - ONT
SFOONT
San Francisco
Mon 10/27
10:38 pm-12:07 am
Nonstop1h 29m
Ontario
Thu 10/30
10:40 pm-12:09 am
Nonstop1h 29m
$77
Showing 1-10 of 20 results
The best insider tips for San Francisco to Ontario flights
Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your San Francisco to Ontario trip
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.
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
Airlines
How far ahead should I book a flight from San Francisco to Ontario?
Use this chart to determine the optimal time to book a round-trip flight from San Francisco to Ontario. Price data was last updated on August 8, 2025.
Booking 89 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 $246). Flying from San Francisco to Ontario in March is currently the most expensive (average of $328). 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 August 21, 2025.
Unlike in the afternoon, when flights are generally more expensive, you can save up to 34% on flights from San Francisco to Ontario by exploring options for tickets at noon.
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 August 17, 2025.
Travelers seeking maximum savings on their San Francisco to Ontario flight should consider departing on Saturday at noon when fares are most often at their lowest. Friday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.
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 August 21, 2025.
Peruse reviews from past customers who have flown with Alaska Airlines, Delta, and United 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.
Boarding
8.1
Food
7.1
Overall
8.0
Crew
8.5
Entertainment
7.0
Comfort
7.8
Reviews
1 / 20
10.0
ExcellentJames,Apr 2025
LAX - SFO
Boarding
8.1
Food
7.1
Overall
8.0
Crew
8.5
Entertainment
7.0
Comfort
7.8
Reviews
1 / 20
10.0
ExcellentJames,Apr 2025
LAX - SFO
Boarding
8.1
Food
7.1
Overall
8.0
Crew
8.5
Entertainment
7.0
Comfort
7.8
Reviews
1 / 20
10.0
ExcellentJames,Apr 2025
LAX - SFO
Boarding
8.1
Food
7.1
Overall
8.0
Crew
8.5
Entertainment
7.0
Comfort
7.8
Reviews
1 / 20
10.0
ExcellentJames,Apr 2025
LAX - SFO
Boarding
8.1
Food
7.1
Overall
8.0
Crew
8.5
Entertainment
7.0
Comfort
7.8
Reviews
1 / 20
10.0
ExcellentJames,Apr 2025
LAX - SFO
Boarding
8.1
Food
7.1
Overall
8.0
Crew
8.5
Entertainment
7.0
Comfort
7.8
Reviews
1 / 20
10.0
ExcellentJames,Apr 2025
LAX - SFO
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.
Browse thousands of different options on Cheapflights for your next trip
Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
Alternative routes for San Francisco to Ontario
See prices for flight routes from nearby airports that may be better suited for you.
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 2,558,603 searches. Data last updated August 21, 2025.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$39 | Average$108 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$42 | Average$89 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$58 | Average$230 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$59 | Average$197 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$75 | Average$188 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$186 | Average$221 | FlexibilityNo cancel fee | On-time71% |