$39 Cheap United flights San Francisco (SFO) to Ontario (ONT)

View $39 flight on Wed, Oct 8, 2025Opens in a new window

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$39 Cheap United flights San Francisco (SFO) to Ontario (ONT)

Prices were available within the past 7 days and start at $39 for one-way flights and $90 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Tue, Sep 23 - Sun, Sep 28
SFO
San Francisco
ONT
Ontario
$90 Roundtrip, found 21 hours ago
$90
Roundtrip
found 21 hours ago
Select United flight, departing Tue, Sep 23 from San Francisco to Ontario, returning Sun, Sep 28, priced at $90 found 21 hours ago
United
Sun, Sep 21 - Wed, Sep 24
SFO
San Francisco
ONT
Ontario
$97 Roundtrip, found 1 hour ago
$97
Roundtrip
found 1 hour ago
Select United flight, departing Sun, Sep 21 from San Francisco to Ontario, returning Wed, Sep 24, priced at $97 found 1 hour ago
United
Sat, Sep 27 - Sun, Sep 28
SFO
San Francisco
ONT
Ontario
$100 Roundtrip, found 6 hours ago
$100
Roundtrip
found 6 hours ago
Select United flight, departing Sat, Sep 27 from San Francisco to Ontario, returning Sun, Sep 28, priced at $100 found 6 hours ago
United
Mon, Oct 27 - Thu, Oct 30
SFO
San Francisco
ONT
Ontario
$102 Roundtrip, found 1 hour ago
$102
Roundtrip
found 1 hour ago
Select United flight, departing Mon, Oct 27 from San Francisco to Ontario, returning Thu, Oct 30, priced at $102 found 1 hour ago
United
Mon, Oct 6 - Thu, Oct 9
SFO
San Francisco
ONT
Ontario
$104 Roundtrip, found 1 hour ago
$104
Roundtrip
found 1 hour ago
Select United flight, departing Mon, Oct 6 from San Francisco to Ontario, returning Thu, Oct 9, priced at $104 found 1 hour ago
United
Sat, Nov 8 - Tue, Nov 11
SFO
San Francisco
ONT
Ontario
$111 Roundtrip, found 1 hour ago
$111
Roundtrip
found 1 hour ago
Select United flight, departing Sat, Nov 8 from San Francisco to Ontario, returning Tue, Nov 11, priced at $111 found 1 hour ago
Flights from San Francisco (SFO) to Ontario (ONT)
Origin airport
San Francisco Intl.
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Popular airline
United
Distance
363 mi
Average flight time
1 hour 25 mins

Frequently asked questions

How much is a United Airlines flight from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
Apply the "Price (lowest to highest)" filter on Expedia to find cheap United Airlines round-trip flights from $90 from SFO to ONT. Affordable one-way fares from $39 are available as well.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.
What is the cheapest month to fly from SFO to ONT with United Airlines?
January is one of the least expensive months to jet off to Ontario with United Airlines. You could also find great prices on one-way and return tickets in April.
What is the cheapest time to book flights from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT) with United Airlines?
Begin your search one to three months ahead of your departure date to find cheaper fares on United Airlines flights from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT). You can save 25% by booking your domestic flight 34 to 86 days in advance versus last-minute reservations made 6 to 12 days out. You could also reduce costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Get the timing right, and you can enjoy significant savings on domestic trips.*Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.
Does United Airlines fly nonstop from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
Easily travel from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT) on any of United Airlines's 18 direct weekly flights. Apply our "Nonstop" and "Airline" filters to find the United Airlines flight that'll take you to ONT at your preferred time.
How long does it take to fly from SFO to ONT with United Airlines?
On average, it takes 1h 29m to travel nonstop from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT) with United Airlines.
Which day of the week has the most United Airlines flights from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
United Airlines operates the most flights from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT) on Thursday. With up to 3 daily departures, you'll get the most flexibility on this day.
What is the earliest United Airlines flight from SFO to ONT?
The first United Airlines flight from SFO to ONT departs at 8:25AM UTC-8, touching down at 9:51AM UTC-8. If you prefer to jet off later in the day, the last United Airlines flight leaves SFO at 7:00PM UTC-8 and lands at ONT at 8:29PM UTC-8. Flying earlier is often a wise choice as morning flights tend to experience fewer cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports does United Airlines fly into in Ontario?
Los Angeles - Ontario Intl. Airport (ONT) is the main Ontario hub for United Airlines flights from San Francisco Intl. Airport (SFO). Los Angeles Intl. Airport (LAX) and John Wayne Airport (SNA) are alternative possibilities. When organizing your trip through Expedia, check the "All Airports" option for your destination to see all available choices.
Why fly with United Airlines from SFO to ONT?
Travel from SFO to ONT with United Airlines and you'll enjoy a range of benefits including a rewarding loyalty program. When booking through Expedia as a United Mileage Plus and One Key™ member, you may also earn OneKeyCash™* to spend on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.
What type of plane does United Airlines fly from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
United Airlines generally flies Embraer 175 planes for flights from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT). This carrier also operates the Airbus A320 on this route. Remember that aircraft type can vary due to operational reasons, so the plane you catch might be different when you leave.
Can I change or cancel my United Airlines flight from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
It's generally possible to modify or cancel your flight, although additional fees may apply if you made your booking more than 24 hours ago. Prefer to keep your options open? Use Expedia's "Changes included" or "No cancel fee" filter to find flights that won't charge extra if you need to adjust your plans. To make changes, head to "Trips," select your flight and click on "Manage Booking" for further information.

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