$29 Cheap Flights from San Francisco (SFO) to Ontario (ONT)

View $29 flight on Tue, Aug 12, 2025Opens in a new window

Popular airlines from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)

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Cheap Flights from San Francisco to Ontario (SFO-ONT)

Prices were available within the past 7 days and start at $29 for one-way flights and $57 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Thu, Aug 7 - Sun, Aug 10
SFO
San Francisco
ONT
Ontario
$57 Roundtrip, found 1 hour ago
$57
Roundtrip
found 1 hour ago
Select United flight, departing Thu, Aug 7 from San Francisco to Ontario, returning Sun, Aug 10, priced at $57 found 1 hour ago
United
Sat, Jul 12 - Thu, Jul 17
SFO
San Francisco
ONT
Ontario
$67 Roundtrip, found 12 hours ago
$67
Roundtrip
found 12 hours ago
Select United flight, departing Sat, Jul 12 from San Francisco to Ontario, returning Thu, Jul 17, priced at $67 found 12 hours ago
Frontier Airlines
Mon, Aug 4 - Fri, Aug 8
SFO
San Francisco
ONT
Ontario
$68 Roundtrip, found 3 hours ago
$68
Roundtrip
found 3 hours ago
Select Frontier Airlines flight, departing Mon, Aug 4 from San Francisco to Ontario, returning Fri, Aug 8, priced at $68 found 3 hours ago
Frontier Airlines
Mon, Aug 11 - Thu, Aug 21
SFO
San Francisco
ONT
Ontario
$69 Roundtrip, found 1 hour ago
$69
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Mon, Aug 11 from San Francisco to Ontario, returning Thu, Aug 21, priced at $69 found 1 hour ago
Frontier Airlines
Fri, Aug 8 - Tue, Aug 12
SFO
San Francisco
ONT
Ontario
$73 Roundtrip, found 14 hours ago
$73
Roundtrip
found 14 hours ago
Select Frontier Airlines flight, departing Fri, Aug 8 from San Francisco to Ontario, returning Tue, Aug 12, priced at $73 found 14 hours ago
United
Mon, Aug 4 - Mon, Aug 18
SFO
San Francisco
ONT
Ontario
$74 Roundtrip, found 1 day ago
$74
Roundtrip
found 1 day ago
Select United flight, departing Mon, Aug 4 from San Francisco to Ontario, returning Mon, Aug 18, priced at $74 found 1 day ago
Frontier Airlines
Mon, Jul 21 - Fri, Aug 8
SFO
San Francisco
ONT
Ontario
$79 Roundtrip, found 4 days ago
$79
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Mon, Jul 21 from San Francisco to Ontario, returning Fri, Aug 8, priced at $79 found 4 days ago
Southwest Airlines
Wed, Aug 6 - Mon, Aug 11
SFO
San Francisco
ONT
Ontario
$100 Roundtrip, found 12 hours ago
$100
Roundtrip
found 12 hours ago
Select Southwest Airlines flight, departing Wed, Aug 6 from San Francisco to Ontario, returning Mon, Aug 11, priced at $100 found 12 hours ago
Alaska Airlines
Tue, Aug 19 - Wed, Aug 27
SFO
San Francisco
ONT
Ontario
$282 Roundtrip, found 6 hours ago
$282
Roundtrip
found 6 hours ago
Select Alaska Airlines flight, departing Tue, Aug 19 from San Francisco to Ontario, returning Wed, Aug 27, priced at $282 found 6 hours ago
Delta
Tue, Aug 19 - Wed, Aug 27
SFO
San Francisco
ONT
Ontario
$283 Roundtrip, found 6 hours ago
$283
Roundtrip
found 6 hours ago
Select Delta flight, departing Tue, Aug 19 from San Francisco to Ontario, returning Wed, Aug 27, priced at $283 found 6 hours ago

Find the cheapest month to fly from San Francisco (SFO) to Ontario (ONT)

July is typically the cheapest month to fly

From $48 - $119 per traveler.

Graph displaying average flight prices per month

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, JetBlue Airways, Southwest Airlines, United
Roundtrip price
$51
Distance
363 mi
Average flight time
1 hour 28 mins

San Francisco to Ontario Flights

The cheapest times to fly from San Francisco to Ontario

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from San Francisco to Ontario are during the month of August. You can find some of the cheapest flights from San Francisco to Ontario with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from San Francisco to Ontario

Sunday is one of the best days to book for cheap flights from San Francisco to Ontario: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from San Francisco to Ontario

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from San Francisco to Ontario in 2025. You can also book with separate airlines for your outbound and return journeys, from $29 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap San Francisco to Ontario flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your San Francisco to Ontario airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT) cost?
Cheap return fares from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT) start at $48. This information is based on the cheapest price found on Expedia for this return journey departing within the next three months. This airfare is for a Frontier Airlines flight leaving SFO on July 28 2025 and touching down at ONT. The price was last updated on July 3 2025 and has not changed since.
What is the cheapest month to fly from SFO to ONT?
The cheapest flights from SFO to ONT are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
When jetting out of San Francisco Intl. Airport (SFO), you can board a nonstop flight to Los Angeles - Ontario Intl. Airport (ONT) with United Airlines.
What is the cheapest airline that flies from SFO to ONT?
At the moment, the cheapest airline offering one-way flights from SFO to ONT is Frontier Airlines. You can take off on this route from $24. This fare is based on the lowest price found on Expedia departing within the next three months. The flight takes off from SFO on August 11 2025. Prices were last updated on July 3 2025 and have not changed since.
How many flights per day from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
When departing from San Francisco Intl. Airport (SFO), you'll have a choice from an average of 3 daily direct flights to Los Angeles - Ontario Intl. Airport (ONT).
What are the most popular departure times for flights from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
Flights between SFO and ONT are their busiest at 4 PM. If you're after a more relaxed experience and potentially cheaper tickets, look for a departure outside the usual busy windows.
What day of the week has the most flights from SFO to ONT?
Friday offers the most flights from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT). Consider leaving on this day and you'll have a greater chance of finding a departure that fits your schedule.
What is the earliest flight from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
Take the earliest flight at around 8:25AM UTC-8, departing from San Francisco Intl. Airport (SFO). You'll be traveling for roughly 1h 26m, coming in to land at Los Angeles - Ontario Intl. Airport (ONT) at approximately 9:51AM UTC-8.
How long does it take to fly from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
Flights from SFO to ONT have an average travel time of 1 hour and 29 minutes. The total distance between the two is 360 mi.
What airline has the least delays from SFO to ONT?
United Airlines has the best performance for on-time direct flights from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT), with an on-time rating of 84%. Use the Expedia App to view your flight schedule before you leave and receive notifications about any trip changes.
What is the best time to fly from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
To avoid possible delays on the San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT) route, fly before 3 PM. Later departures have a 22% higher chance of cancellation.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for Ontario from San Francisco Intl. Airport (SFO)?
If you're catching a direct flight from San Francisco Intl. Airport (SFO) to Ontario, you can land at any one of these hubs:

  • Los Angeles Intl. Airport (LAX)
  • John Wayne Airport (SNA)
  • Bob Hope Airport (BUR)
  • Los Angeles - Ontario Intl. Airport (ONT)
  • San Bernardino, CA (SBD-San Bernardino Intl.)

Is it cheaper to buy a plane ticket from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT) last-minute?
Last-minute fares from SFO to ONT are usually more expensive. For the lowest rates, start looking for flights as soon as possible. That being said, if you're flexible with your travel plans, it's possible to score a cheap ticket right before your journey.
Is it cheaper to book a SFO to ONT flight and hotel package?
Compared with arranging flights and hotels separately, booking a SFO to ONT flight and hotel package with Expedia could lead to significant savings. Better yet, having everything in one easy place takes the hassle out of planning your trip. Just secure your flights and select from our extensive range of stays, then tailor your trip with extras like tours, car rentals and activities.
Can I cancel or change the date of my flight from San Francisco Intl. Airport (SFO) to Los Angeles - Ontario Intl. Airport (ONT)?
Typically, you can cancel or modify your SFO to ONT flight. However, there may be additional fees, especially if you booked more than 24 hours ago. Double-check your itinerary for the airline's fees and policies on flight changes, or if you'd like further details, visit our Customer Service portal.

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