SFO - ONT

$63 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 6/1. 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.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from San Francisco to Ontario.
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Everything you should know

Cheapest round-trip
$98
Typical prices: $237-$99
Frontier
Wed 4/15Thu 4/16
SFO - ONT • 1 stop
Cheapest non-stop
$115
Typical prices: $190-$70
Frontier
Wed 5/6Wed 5/13
SFO - ONT • Non-stop
Advice from real travelers
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
Top airlines
Cheapest • from $98 (round-trip)
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
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Airline reviews
Airline reviews
+1
Nonstop flights
You can fly direct with Frontier and United Airlines. Average duration is 1h 35m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
Avoid delays
Most punctual • 87% on-time
Best time • Fewest delays
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 2 weeks in advance save around 24% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 41% price drop
Most popular
Good to know
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+1
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Ontario!
Flight Deals
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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

Wed, Apr 15 - Thu, Apr 16
Frontier Logo
2:47 pm - 6:49 pm
SFO
-
ONT
4h 02m
1 stop
Frontier Logo
9:10 am - 10:50 am
ONT
-
SFO
1h 40mnonstop
$98Frontier
Tue, May 5 - Tue, May 5
Frontier Logo
11:26 am - 1:05 pm
SFO
-
ONT
1h 39mnonstop
Frontier Logo
4:39 pm - 10:41 am
ONT
-
SFO
18h 02m
1 stop
$108Frontier
Tue, Apr 14 - Thu, Apr 16
Frontier Logo
2:47 pm - 10:44 am
SFO
-
ONT
19h 57m
1 stop
Frontier Logo
9:10 am - 10:50 am
ONT
-
SFO
1h 40mnonstop
$109Frontier
Thu, Apr 23 - Fri, Apr 24
Frontier Logo
9:18 am - 10:52 am
SFO
-
ONT
1h 34mnonstop
Frontier Logo
9:12 am - 9:33 pm
ONT
-
SFO
12h 21m
1 stop
$114Frontier
Wed, May 6 - Wed, May 13
Frontier Logo
11:26 am - 1:05 pm
SFO
-
ONT
1h 39mnonstop
Frontier Logo
8:17 pm - 9:55 pm
ONT
-
SFO
1h 38mnonstop
$115Frontier
Tue, May 5 - Wed, May 6
Frontier Logo
11:26 am - 1:05 pm
SFO
-
ONT
1h 39mnonstop
Frontier Logo
8:17 pm - 9:55 pm
ONT
-
SFO
1h 38mnonstop
$116Frontier
Thu, Apr 23 - Thu, Apr 23
Frontier Logo
9:18 am - 10:52 am
SFO
-
ONT
1h 34mnonstop
Frontier Logo
5:33 pm - 12:27 am
ONT
-
SFO
6h 54m
1 stop
$120Frontier
Tue, May 26 - Sat, May 30
Frontier Logo
11:15 am - 12:54 pm
SFO
-
ONT
1h 39mnonstop
Frontier Logo
8:17 pm - 9:55 pm
ONT
-
SFO
1h 38mnonstop
$121Frontier
Thu, Apr 16 - Fri, Apr 17
Frontier Logo
9:18 am - 10:52 am
SFO
-
ONT
1h 34mnonstop
Frontier Logo
9:12 am - 9:13 pm
ONT
-
SFO
12h 01m
1 stop
$123Frontier
Sat, May 2 - Sun, May 3
Frontier Logo
2:47 pm - 6:49 pm
SFO
-
ONT
4h 02m
1 stop
Frontier Logo
9:19 am - 10:59 am
ONT
-
SFO
1h 40mnonstop
$124Frontier
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.

How much is a round-trip flight from San Francisco to Ontario?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from San Francisco to Ontario departing in April.

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 $317 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 24% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 15 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$63
Best time to beat the crowds but there is an average 27% increase in price.
Most popular time to fly and prices are also 41% 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 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 $63 for a one-way ticket and $98 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, JetBlue, and American 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 Boeing 737 MAX 9 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, Southwest or Delta?

    The two airlines most popular with KAYAK users for flights from San Francisco to Ontario are Southwest and Delta. With an average price for the route of $236 and an overall rating of 8.0, Southwest 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 $78 or less one-way and $187 or less round-trip.

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,Frontier

United Airlines,Frontier

Wednesday

United Airlines,Frontier

United Airlines,Frontier

Thursday

Frontier,United Airlines

Frontier,United Airlines

Friday

Frontier,United Airlines

Frontier,United Airlines

Saturday

United Airlines,Frontier

United Airlines,Frontier

Sunday

Frontier,United Airlines

Frontier,United Airlines

See more direct flights

Direct returns

Ontario to San Francisco

Monday

Frontier,United Airlines

Frontier,United Airlines

Tuesday

United Airlines,Frontier

United Airlines,Frontier

Wednesday

United Airlines,Frontier

United Airlines,Frontier

Thursday

Frontier,United Airlines

Frontier,United Airlines

Friday

Frontier,United Airlines

Frontier,United Airlines

Saturday

United Airlines,Frontier

United Airlines,Frontier

Sunday

Frontier,United Airlines

Frontier,United Airlines

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.
7.9
Alaska AirlinesOverall score based on 12121 reviews
7.0Entertainment
8.1Boarding
7.0Food
7.8Comfort
8.5Crew
Airline reviews

Four hour delay. Missed our event. And they offered me $75. Absolutely shameful.

2.0 MediocreEric, Mar 2026
SFO - SAN
Read more Alaska Airlines reviews

Four hour delay. Missed our event. And they offered me $75. Absolutely shameful.

I have been flying commercial for decades. I was in one of the ladder boarding groups, had my bag tagged because they thought there was not going to be enough space for it in the overhead bins. I politely asked one of the attendance if I could try to find a space- she said I could and I did. I then took the bag tag off and gave it to one of the other attendants as I was told to do by the first one. He, in a curt, anal, and disrespectful manner, told me that I needed to take my bag down from the overhead bin and check it. This was a situation I’ve never encountered before. The attendant’s attitude was confrontational and belittling in front of other onlooking passengers as if daring me to challenge him. I am a physician who takes care of patients day in and day out. Not wanting to make a scene, I calmly told him, “do what you need to do.” he took my bag down from the overhead bin, put the back tag back on it, and checked it only to make room for another bag that was also supposed to be technically checked by a following passenger. The same male attendant later came up to me and said “you shouldn’t have showed me the bag tag,” as if conveying that he was just following protocol was a justification for treating me like a kid out of line. I cared about this because it took 15 minutes from my life to then retrieve the bag at baggage claim and it also felt like really poor customer service. I understand the need for protocols. This is also a service industry, and we the passengers are the clients. We should be made to feel welcome and respected and our life in transit made as easy as it can be within reason. This attendant clearly needs to be reminded of that. Of note, an older female fellow passenger sitting next to me agreed with this assessment.

I love Alaska! We arrived on the later side without seat assignments only to find the had oversold the flight by 1. The attendants worked extra hard to find a way for our party of 7 to stay together and we made it on the flight! Loved the free WiFi also!

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.

The cabin temperature was nice and cool. The wifi was not working.

As previously noted, this flight was great: departure was timely, the crew was friendly and attentive, and wifi connectivity was seamless. In particular, I appreciated that the flight attendant just told me to stow the laptop right before takeoff/landing, and trusted me to do so (which I did!).

Left a few minutes early. Got in 15 minutes early. Very attentive service on board. Very organized boarding.

There’s not much to say about a one hour flight. This is a connection from LA to RNO that I missed the previous night due to a mechanical check delay on my originating flight from JFK to LAX. The short flight itself was fine. Instructions from the pilot and crew were per usual. The coffee was barely lukewarm, which possibly was purposeful so we would down it quickly. Bags were already on carousel upon reaching baggage claim, which was excellent.

Delta continues to set the benchmark for traveler-friendly service with minimal disruption and clear communication within the mainland US (coast to coast). I am consistently pleased to be a Delta customer, and this experience once again met my expectations. There was a brief delay departing from MIA due to a technical issue that required the aircraft to return to the gate. However, the situation was handled professionally and transparently. Fortunately, my planned layover allowed ample buffer time, so the adjustment caused no stress. Overall, another smooth and reassuring experience.

The plane was an older model, so it wasn’t as comfortable as others. The flight attendants were not helpful during onboarding. It was a full flight so there was chaos finding space for baggage.

Awesome! On time flight, early arrival, and a complimentary upgrade!

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.

They delayed the flight from 9:00 to 11:55 At 11:45 they canceled the flight. I paid a premium price for the tickets with poor service

Seats are uncomfortable. This has been a trend in the industry for decades. Trying to fit more seats on each plane to increase profits at the expense of the passenger.

Staff were good. My seat was in need of repair, but for a short flight was not problematic. Usual basic snack and drink setup that you'll find on any US carrier. Over, a decent, basic flight.

Flight delayed for more than 16 hrs and no effort was spent to provide an alternate

it was a very short flight so my expectations were low.

Very disappointing given gate agent behavior. Filed a formal complaint with United.

Terrible. No customer service, no food, no drinks on a 6 hour premier economy booking.

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

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

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.

Delayed for mechanical and no updates on what was happening and how long the delay might be.

A first class seat should fit a fat person, and this doesn't. The trays in the armrest are less functional than an ordinary tray in the back of the seat.

The experience at checkin for my American Airlines flight from Sacramento to LAX was very good including the assistance I received in getting my bags checked in and boarding passes printed. Was pleasantly surprised the my bags were checked through all the way to my destination at Clark International Airport in Angeles, Philippines.

Not good. One of my luggage is missing. And until now they can’t find it

Dloght delayed by 2.5 hrs . Common theme in my last four american floghts

The worst Airline ever. They centered my second flight and leave me in NY. They don’t have any representatives at the airport and they don’t respond to calls. Basically I got stuck. I will never purchase through there again.

The chicken wrap was tiny ($13 for what looked like a 1/3 of a normal wrap?) and disgusting.

Smooth flight. From the early boarding and all were on board before departure time and arrived early in ONT. Great crew. Thank you!!!!

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

Remind customers of the need to have passport or new ID for boarding.

The flight never took off and we spent 7 hours at the airport

Our flight was canceled. I will never use Kayak nor Frontier for travel again. The entire experience was a headache.

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.

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

Information on your arrival and departure airports