SFO - ONT

Find cheap flights from San Francisco to Ontario

1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Ontario

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from San Francisco to Ontario, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from San Francisco to Ontario, as well as popular online travel agencies
Travellers love KAYAK
41.299.237 searches in the past 7 days on KAYAK

Save 24% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Free to useThere are no hidden charges or fees.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Everything you should know

Cheapest round-trip
Multiple Airlines
Thu 20/11
SFO - ONT • multi-stop
Cheapest one-way flights
Multiple Airlines
Thu 20/11
SFO - ONT • multi-stop
Our travellers' advice
AI-generated summary based on content written by travel experts
United's Economy Plus offers extra legroom on this route.
Frontier's Premium Bundle adds priority boarding for $20.
Expert advice
Expert advice
Expert advice
Expert advice
When to book
2 weeks
in advance
Our data shows that travellers who book at least 2 weeks in advance save around 11% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
February
Cheapest • 34% price drop
November
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to Ontario!
Flight Deals
Booking Insights
Expert advice
Flight Deals

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

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from San Francisco to Ontario that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from San Francisco to Ontario

Multiple Airlines Logo
SFO-ONT
941 kmmulti-stop
Multiple Airlines Logo
ONT-SFO
941 kmmulti-stop
Multiple Airlines
Find Deal
Booking Insights

KAYAK's insights & trends for San Francisco to Ontario flights

Get data-powered insights and trends into flights from San Francisco to Ontario to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest month to fly from San Francisco to Ontario?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from San Francisco to Ontario, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from San Francisco to Ontario is February, where tickets cost C$ 147 (return) on average. On the other hand, the most expensive months are December and July, where the average cost of round-trip tickets is C$ 320 and C$ 287 respectively.

Can I save money by flying with a layover from San Francisco to Ontario?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of C$ 203, prices are generally cheapest when you fly direct.

How far in advance should I book a flight from San Francisco to Ontario?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from San Francisco to Ontario, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from San Francisco to Ontario, you should book around 2 weeks before departure, which saves you about 11% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 10 weeks before departure.

Expert advice

Expert advice for your flight from San Francisco to Ontario

 
Snippets provided in this section are AI-generated based on a summarisation of KAYAK-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.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Airlines
Frontier

Frontier's Premium Bundle offers priority boarding and extra legroom for just $20 more than Economy.


Avoid middle seats by selecting Economy Bundle for free Standard seat selection and carry-on bag.

United Airlines

United's Economy Plus offers up to six inches more legroom than standard economy seats.


United offers free messaging on most flights, with additional Wi-Fi options available.

Airports
SFO

SFO offers curbside check-in for United, Delta, and Southwest, making it convenient for travelers with kids or heavy luggage.

ONT

For a budget-friendly arrival, use Omnitrans Bus Route 61 from ONT to nearby transit centers, operating frequently during peak hours.

Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on Frontier and United Airlines

Stefanie Waldek

Stefanie Waldek

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Read more
Jennifer Simonson

Jennifer Simonson

Expert on ONT

Jennifer Simonson

Jennifer Simonson

Jennifer Simonson is driven by her lifelong commitment to exploring the globe. Her insatiable curiosity had led her to immerse herself into diverse locations like Oklahoma City and Pismo. Her hotel recommendations are the result of the myriad hotels she's stayed at across her travels. Along her journey, she cherishes engaging conversations with locals, indulging in the finest ice cream, trying her hand at surfing, and embarking on nature-filled hikes.

Read more
Blane Bachelor

Blane Bachelor

Expert on SFO

Blane Bachelor

Blane Bachelor

Blane Bachelor is a journalist and editor specializing in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favorite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history. She will always choose the window seat.

Read more

Good to know

Low seasonFebruary
Best time to beat the crowds (34% less expensive on average)
Most popular time to fly (19% more expensive on average)

When to book flights from San Francisco to Ontario

Are your dates flexible? Find out the best times to travel from San Francisco to Ontario based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from San Francisco to Ontario

  • What happens upon losing an item at ONT?

    If you have lost your item when traveling to ONT, you can visit the lost and found offices. The offices are in terminal 2 just behind the information desk. The lost and found offices operate from Monday through Friday from 7am to 3:30pm.

  • Are there any electric vehicle charging stations at SFO?

    Yes, there are several electric vehicles charging stations that are easily accessible. The charging stations are located at the domestic garage level 1, Long-term garage 2, and the international garage level 2. The charging stations are available on a first-come, first-served basis.

  • Is SFO safe for kids?

    Yes, SFO airport is child-friendly and you can travel with your children easily. Several nursery spots are located at terminals 1, 2, and 3, international terminal A gates, international terminal main hall, and international terminal G gates. There are shower facilities at the entire airport to enable you to freshen up before traveling with your child.

  • Is safety assured at ONT?

    At ONT airport, there are security screening procedures to guarantee your safety. The security screening commences upon your arrival at the airport. It is advisable to declare all your electronics at the security screening center to avoid inconveniences. The security screening procedures often change; hence it’s advisable to be flexible and adjust accordingly.

  • Which airlines offer Wi-Fi service onboard planes from San Francisco to Ontario?

    Alaska Airlines, Delta, American Airlines, JetBlue, and Hawaiian Airlines offer inflight Wi-Fi service on the San Francisco to Ontario flight route.

  • Which aircraft models fly most regularly from San Francisco to Ontario?

    The Airbus A320neo is the aircraft model that flies most regularly on the San Francisco to Ontario flight route.

  • Which airline alliances offer flights from San Francisco to Ontario?

    Star Alliance is the only airline alliance operating flights between San Francisco and Ontario.

  • On which days can I fly direct from San Francisco to Ontario?

    There are direct flights from San Francisco to Ontario on a daily basis.

  • How does KAYAK find such low prices on flights from San Francisco to Ontario?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from San Francisco to Ontario.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from San Francisco to Ontario?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario from San Francisco is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from San Francisco to Ontario?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Ontario with an airline and back to San Francisco with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from San Francisco to Ontario?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Ontario from San Francisco up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from San Francisco to Ontario

  • Looking for a cheap flight? 25% of our users found flights on this route for C$ 96 or less one-way.
  • Want to secure a parking spot in advance when traveling to Ontario International Airport (ONT)? It is advisable to book early via the online system. This will enable you to choose your parking spot and ideal date and time. With this booking, there is an assurance your parking spot will be vacant before your arrival. There is tightened security at the parking lot; hence no need to worry about the security of your vehicle.
  • Upon arriving at San Francisco International Airport (SFO), you can get access to free Wi-Fi. The Wi-Fi is strong in all terminals enabling you to watch your favorite movie or game while waiting to catch your flight. You only need to select the SFO Wi-Fi network and launch your browser.
  • You can only travel with your pet at SFO airport if it is kenneled. Your pet will be delivered to the baggage claim area if traveling with it. Before your flight commences, you can take your pet to the relief areas located in terminals 1, 2, and 3. If you wish to import or export a pet at SFO, it is advisable to make prior arrangements to minimize any inconveniences.
  • There is a medical clinic onsite at SFO where you can visit in case you feel unwell. The clinic features state-of-the-art equipment to aid in your treatment. Upon diagnosis, you will be provided with travel medicine to make you feel better. The average wait time is less than 15min, but you can book an appointment before arrival.
  • SFO features an AirTrain that connects all the airport terminals at the airport. Some of the items allowed on the AirTrain include animals, bicycles, and airport luggage carts. The departure time is always indicated on the screens

Prefer to fly direct from San Francisco to Ontario?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from San Francisco to Ontario.
Find which airlines fly direct from San Francisco Airport to Ontario Airport, which days they fly and book direct flights.

Direct departures

San Francisco to Ontario

Monday

Frontier,United Airlines

Frontier,United Airlines

Tuesday

United Airlines

United Airlines

Wednesday

United Airlines

United Airlines

Thursday

Frontier,United Airlines

Frontier,United Airlines

Friday

Frontier,United Airlines

Frontier,United Airlines

Saturday

United Airlines

United Airlines

Sunday

Frontier,United Airlines

Frontier,United Airlines

See more nonstop flights

Direct returns

Ontario to San Francisco

Monday

Frontier,United Airlines

Frontier,United Airlines

Tuesday

United Airlines

United Airlines

Wednesday

United Airlines

United Airlines

Thursday

Frontier,United Airlines

Frontier,United Airlines

Friday

Frontier,United Airlines

Frontier,United Airlines

Saturday

United Airlines

United Airlines

Sunday

Frontier,United Airlines

Frontier,United Airlines

See more nonstop flights

Reviews of the top airline flying from San Francisco to Ontario

 
See real verified KAYAK customer reviews for airlines flying from San Francisco to Ontario. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from San Francisco to Ontario? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
United AirlinesOverall score based on 9029 reviews
6.6Food
7.7Boarding
8.1Crew
7.3Comfort
7.1Entertainment
Airline reviews

Older aircraft, no meal, only food was for purchase. Not impressed United.

4.0 OkayThomas, Nov 2025SFO - KOA
Read more United Airlines reviews

Older aircraft, no meal, only food was for purchase. Not impressed United.

Not pleasant trip cross country when the entertainment and WiFi system not working. No entertainment for entirety of route. Staff was rather nonchalant in that they dismissed the problem due to age of plane. It would have been nice to know this up front so I could have come prepared to read or download movies before boarding Coincidentally or not, there was a similar issue with the entertainment system on my previous flight I took on my fist leg of the trip. There are no seat TVs, so you must rely on the app when it works. United can do better. Also, what use it it to pay for boarding group 2 when half of the passengers are in the same line as you?

My experience on this United Airlines flight was highly uncomfortable, primarily due to two issues: Cabin Temperature: The temperature on the Boeing 737 MAX 8 was unacceptably high, feeling consistently around 80 degrees throughout the flight. This made sleeping impossible and significantly detracted from the experience. Seating Arrangement: Being stuck in a middle seat for a six-and-a-half-hour overnight flight compounded the discomfort. Moving forward, I will always purchase a seat assignment to avoid this situation.

Premium Plus is a really good idea for longer flights

Same as last comment. Food sucks. Quality. Not surprising most people have no clue about nourishment Clearly

We were in business class. the angled seats in that class do not have a real window view & the placement of the controls are bad. But we knew that. But the food options were mediocre. The taste was fine, but the size was for a child. It’s just really feels like United is skimping on everything. Even when we were in the Polaris lounge they did not have diet sodas. They said they were out no Coke zero no Diet Coke, etc. I do not think the portion of nuts they serve on the plane could get any smaller. Really a minimal service and offer for what you’re paying for in business.

We had to deboard 2 times due to maintenance issues. They changed the plane, and then we got deviated to LAX due to maibtenance issues on the other plane, had to sleep at LAX and los a full day.

From the first moment you interact with United Airlines, you can expect nothing less but extreme frustration. The baggage handler at the bag drop seems completely unbothered by the presence of customers waiting in line. No help was extended to load the baggage whatsoever. And if any of your bags is overweight by 0.01 pound they will make you re-distribute everything in your suitcase just to play power trip. When it was time to board no help was extended to customers to locate their seats. Moreover. It was a chaotic mess at the gate when it was unclear who should board first and everyone just bunched up, trying to get on the plane. I am sure the crew was doing their best to perform their jobs while being paid their wages however it shouldn’t be that hard to smile once or twice when you’re in the business if serving customers. It is a shame for the United States of America to have a flagship carrier of such low caliber. Our flight was also delayed by about an hour and a half due to further delays prior to our inbound flight. Being someone who has travelled for both business and leisure in Asia, Europe, and South America I have never experienced such poor quality of service.

The pilots were late and it made us 1 hour late. The meat was tough and bok choy was also tough.

Stuck on tarmac for two hours plus a 5.5 hour flight. Rude flight attendant. And no meals, not even for purchase!

Everything you need to know for your flight from San Francisco to Ontario

Information on your arrival and departure airports