SFO - ONT

$84 Find Cheap Flights from San Francisco to Ontario

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from San Francisco to Ontario departing on 3/20. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
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
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Everything you should know

Cheapest round-trip
$93
Overall average: $152
Frontier
Fri 4/3Mon 4/6
SFO - ONT • Non-stop
Cheapest one-way
$84
Typical prices: $58-$140
Frontier
Fri 3/20
SFO - ONT • Non-stop
Our travelers' advice
AI-powered summary based on content written by travel experts. AI can make mistakes.
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
Video guide: How to find cheap flights to Ontario
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Top airlines
Frontier
Cheapest • from $93 (round-trip)
Alaska Airlines
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
2 weeks
in advance
Our data shows that travelers who book at least 2 weeks in advance save around 26% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
May
Cheapest • 37% price drop
May
Most popular
Good to know
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+1
+1
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We hope you love your trip to Ontario!
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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

Fri, Apr 3 - Mon, Apr 6
Frontier Logo
8:48 am - 10:20 am
SFO
-
ONT
1h 32mnonstop
Frontier Logo
8:49 am - 10:30 am
ONT
-
SFO
1h 41mnonstop
$93Frontier
Fri, Mar 13 - Mon, Mar 16
Frontier Logo
8:53 am - 10:22 am
SFO
-
ONT
1h 29mnonstop
Frontier Logo
9:06 am - 10:48 am
ONT
-
SFO
1h 42mnonstop
$95Frontier
Fri, Mar 13 - Mon, Mar 16
Frontier Logo
8:53 am - 10:22 am
SFO
-
ONT
1h 29mnonstop
Frontier Logo
9:06 am - 10:48 am
ONT
-
SFO
1h 42mnonstop
$97Frontier
Fri, Mar 20 - Mon, Mar 23
Frontier Logo
8:53 am - 10:22 am
SFO
-
ONT
1h 29mnonstop
Frontier Logo
9:06 am - 10:48 am
ONT
-
SFO
1h 42mnonstop
$101Frontier
Thu, Apr 30 - Sun, May 3
Frontier Logo
9:23 am - 10:52 am
SFO
-
ONT
1h 29mnonstop
Frontier Logo
9:02 am - 10:37 am
ONT
-
SFO
1h 35mnonstop
$102Frontier
Fri, Mar 20 - Mon, Mar 23
Frontier Logo
8:53 am - 10:22 am
SFO
-
ONT
1h 29mnonstop
Frontier Logo
9:06 am - 10:48 am
ONT
-
SFO
1h 42mnonstop
$103Frontier
Thu, Apr 16 - Sun, Apr 19
Frontier Logo
9:23 am - 10:52 am
SFO
-
ONT
1h 29mnonstop
Frontier Logo
9:02 am - 10:37 am
ONT
-
SFO
1h 35mnonstop
$104Frontier
Fri, Apr 3 - Sun, Apr 5
Frontier Logo
8:48 am - 10:20 am
SFO
-
ONT
1h 32mnonstop
Frontier Logo
8:49 am - 10:30 am
ONT
-
SFO
1h 41mnonstop
$106Frontier
Tue, Mar 3 - Fri, Mar 6
Frontier Logo
8:25 am - 9:34 pm
SFO
-
ONT
13h 09m
1 stop
Frontier Logo
9:06 am - 10:48 am
ONT
-
SFO
1h 42mnonstop
$108Frontier
Thu, Apr 16 - Mon, Apr 20
Frontier Logo
9:23 am - 10:52 am
SFO
-
ONT
1h 29mnonstop
Frontier Logo
11:44 am - 2:26 pm
ONT
-
SFO
26h 42m
1 stop
$109Frontier
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.

Find cheap flights to Ontario
Find cheap flights to Ontario

Planning a trip from San Francisco to Ontario? KAYAK’s data-powered insights will help you find cheap flights. Learn the best time to fly, how early to book your ticket, and other tips to secure great prices.

What’s the cheapest day of the week to fly from San Francisco to Ontario?

The average price of all round-trip flights from San Francisco to Ontario clicked on KAYAK for each day over the last 12 months.

When flying from San Francisco to Ontario, you should consider leaving on a Monday and avoid Tuesdays if you are looking for the best rates. For your return to San Francisco, you’ll find the best rates on Fridays and the most expensive ones on Mondays.

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 May, where tickets cost $117 (return) on average. On the other hand, the most expensive months are February and January, where the average cost of round-trip tickets is $271 and $252 respectively.

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 26% 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

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on United Airlines and Frontier

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.

Jennifer Simonson

Jennifer Simonson

Expert on ONT

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.

Blane Bachelor

Blane Bachelor

Expert on SFO

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.

Good to know

Low seasonJanuary
Cheapest flight$84
Best time to beat the crowds but there is an average 35% increase in price.
Most popular time to fly and prices are also 38% lower on average.
Flight from San Francisco to Ontario

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.

  • What is the cheapest flight from San Francisco to Ontario?

    In the last 3 days, the lowest price for a flight from San Francisco to Ontario was $84 for a one-way ticket and $93 for a round-trip.

  • Do I need a passport to fly between San Francisco and Ontario?

    Even though you are not required to have a passport, keep in mind that an official ID is needed to board the airplane.

  • Which airports will I be using when flying from San Francisco to Ontario?

    On your way to Ontario, you’ll fly out from San Francisco. You’ll be landing at Ontario.

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

    Alaska Airlines, Delta, American Airlines, and JetBlue 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 A320-100/200 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?

    SkyTeam, oneworld, and Star Alliance are the airline alliances operating flights between San Francisco and Ontario, with SkyTeam being the most commonly used for this route.

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

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

  • Which is the best airline for flights from San Francisco to Ontario, Alaska Airlines or Delta?

    The two airlines most popular with KAYAK users for flights from San Francisco to Ontario are Alaska Airlines and Delta. With an average price for the route of $267 and an overall rating of 8.0, Alaska Airlines is the most popular choice. Delta is also a great choice for the route, with an average price of $231 and an overall rating of 7.9.

  • 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. Booking your flights between San Francisco and ONT can sometimes prove cheaper using this method.

  • 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 $139 or less one-way and $237 or less round-trip.
  • 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

United Airlines, Frontier

United Airlines, Frontier

Friday

Frontier, United Airlines

Frontier, United Airlines

Saturday

United Airlines

United Airlines

Sunday

United Airlines, Frontier

United Airlines, Frontier

See more direct 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

United Airlines, Frontier

United Airlines, Frontier

Friday

Frontier, United Airlines

Frontier, United Airlines

Saturday

United Airlines

United Airlines

Sunday

United Airlines, Frontier

United Airlines, Frontier

See more direct flights

Reviews of the top 5 airlines serving 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.
8.0
Alaska AirlinesOverall score based on 11874 reviews
7.1Food
8.1Boarding
7.0Entertainment
7.8Comfort
8.5Crew
Airline reviews

The he whole flight was very smooth on every aspects.

10.0 ExcellentPhilip, Feb 2026
SFO - SAN
Read more Alaska Airlines reviews

The he whole flight was very smooth on every aspects.

I paid for wifi and it never worked... it was miserable. I couldn't access my shared files to work on the plane, it didn't work on my phone. I paid for nothing but frustration and continual refreshing, hoping it would work

The flight was excellent and very friendly and helpful staff. Will travel again and recommend to friends. Thank you

Did not have In flight service on my round trip due to turbulence. I did not partake in In flight entertainment. Flight descending into LAX was very turbulent. It would have been nice if the pilot communicated with us during that rough descent into LAX to ease the minds of some of us more nervous flyers.

They canceled my flight with only a couple hours before checking in at the airport and offered no alternatives to get home.

The food selections were not good, and entertainment was non existent.

The ground crew did not supply drink or snacks during the layover in SFO. So there weren't many options. Otherwise, it was all great.

Staff inside Portland terminal were rude, made us fell rushed and not at all accommodating to seniors. For this alone I will probably never booked from them again.

Loved the staff ease of flying snacks and free movies and WiFi

boarding was late worst was going back LAX to SFO delayed not once ? but TWICE😡I was at the airport practically almost 5 hours of previous time , very inconvenient! i would have spend longer time with family , I was wanting to avoid TSA line? but it just got me to spend unwanted time @ d airport

Was forced to check in my small carry on, even though I informed the crew it has very fragile items inside

They double booked seats, the gate staff changed my ticket as I was boarding she went over to the computer and changed it without telling me. She messed up an entire three row section for me and others. Other travelers were outraged but the gate staff were so rude, so condescending saying it wasn't their problem to solve. I would rate this a zero if I could. Will not fly Delta again I'll stick with United and American.

Delta’s staff is unmatched. From the gate agents, to the pilots, to the flight attendants… all top of the industry.

I usually get upgraded so my experience is usually amazing. I did not get upgraded this time - which was fine - but the wifi had issues, the monitors were going in & out, & (though not Delta's fault) one of the gentlemen next to me desperately needed a shower.

I really liked the legroom. I am 6’4”.a at For some reason our seats were not together and using the app to fix it didn’t work. Passengers were nice enough to move for us but you should absolutely ensure a parent sits with their child.

Our flight from SFO to MSP was right on time on 11/15/2025. No delays. As we approached MSP at about 8 pm, we circled in the air until 8:40 pm so I don't call that efficient for MSP. I think the captain should announce the delay and why. (as if we all don't know that we are just circling around the area, slowing down, speeding up, slowing down.) Thank you. Marilyn Fischer

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

They changed planes and the new plane couldn’t carry enough fuel to fly across the country so we had to stop in Kansas City to refuel. Flight was delayed .

Flight was too crowded and seats are too small, especially since passengrs are getting larger. Having a middle seat is ALWAYS tough! Woman on my left was large & kept creeping in to my space. Flight personnel were great! Have more savory rather than sweet snacks please.

The crew took good care of us. The flight from ATL to SFO is a longer one, and there were multiple beverage offerings. I like the 757's that Delta uses. Good airplane that is comfortable. I do wish Delta would separate Priority boarding from the better seats. I would gladly take a smaller seat in an open row than be jammed into Comfort just to get priority boarding, just to make sure I don't have to check a bag.

The flight crew where really good. Better then the crew from BNE to SFO

Food should be changed in menu Many muslims travels in this airlime they need to add one Halal meal

left on time, reasonable boarding process arrived early luggage came out quickly

Some flight attendants were great others were cranky. Seats were very tight and sitting on an aisle was very hard as the carts and people walking constantly bumped shoulder and arm.

Pushed back only to get deplaned due to a tire damaged by ground crew. They did at least go pretty fast. The bathrooms should be banned under the Geneva convention. No room to even sit straight on the toilet. The under-seat entertainment units block what little leg room there is.

United airlines has the best customer experience from booking to arrival. I always fly United airlines. The mileage program is excellent

from SFO-> FRA flight, AVML meal was significantly less compared to regular meal, especially no Desert, no Bread, no sides.

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?

Premium Plus is a really good idea for longer flights

The flight was significantly delayed for 6.5 hours because of snow. There was no communication once the plane returned to the gate regarding when the flight would resume. Other flights were departing while our flight was being unloaded for reasons unknown. Our flight also seemed out of the queue regarding further deicing, refueling, and waiting to Taxi to the runway.

They are always late and seats was also not having working charger

We flew in first class. The crew did not offer drinks before the flight took off, but they treated us well during the flight. The food was excellent. There was actually too much food served, but it was nice to have all the options.

did not have enough meal for first class passengers so offer us snack

Amazing I love American. I’ll never fly anyone else if I can help it.

Everything about the flight was lovely. My only suggestion would be to offer a few more options of tv series from Apple TV or HBO.

After the door had been closed, the cockpit makes an announcement that catering is running late and it is not the airline's fault. It is their fault in the sense that we had to sit for 2 hours or more when we could have stayed in the terminal. Poor communications between catering and airline. This caused a young man to lose his temper and he went storming out hitting objects. He had complained to the gate agent that he had already waited at the gate 7 hours and when can the airplane leave? Airilnes do a poor job of explaining delays, maintenance issues, etc. whereas being truthful may gain more sympathy or understanding.

We were told the flight was delayed 5 times, then it was moved to the next day.

The experience with American Airlines was good, although the Philippines Airlines flight was much better (better seats, better food, better entertainment options, overall better). Again, the MIA to LAX flight was fine, but nothing in comparison to the comfort and accommodations of the Philippines Airlines flight from LAX to MNL.

Loved the crew . Absolutely no complaints. Except for luggage lost

It was ok. It was expensive to check 2 bags ($75.00 per bag), and then it took a long time to wait for shuttle to take us from one terminal to the terminal where the plane was taking off at LAX. And all of this for a flight where we had to pay for any food or drink that was not water.

Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.

i was unable to check in the flight. refund requested

I think Frontier was very good at communication. Their app worked very well. Loading was great and the flight was nice and easy.

Great for the price. No wifi or entertainment, but gate agents and crew were fantastic and we boarded quickly and left on time.

Decent clean onboard experience. Okay discount airline experience. Unfortunately, any customer service interactions are difficult and unhelpful. There is no service. Also, a premium seat only gets you premium boarding if you line up first. Once they start general boarding you must go to the back of the line. Not very premium

The crew was mostly okay. The flight attendant who answered our questions was curt and unhelpful unfortunately. He seemed upset and I understand having off days.

Very bad! No good service delayed my second connection flight

They canceled flight. Hard to believe there was even a plane incoming for us to get on

Plane was down graded and I lost my uncharged exit row with more leg room. No mention or offer of refund from podium. Flight attendant was nice to explain this happens often and that I could request a refund via online form submission. I did this and have heard nothing back.

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

Information on your arrival and departure airports