SFO - ONT

Find cheap flights from San Francisco to Ontario – Compare and Save

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

Direct flights
Every day
You can fly direct with Frontier and United Airlines. Average duration is 1h 36m
Direct flights
Direct flights
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Direct flights
Direct flights
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Avoid delays
Most punctual • 86% on-time
Best time • Fewest delays
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travellers who book at least 2 weeks in advance save around 16% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 31% price drop
Most popular
Good to know
Good to know
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Good to know
Good to know
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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
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
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SFO
941 kmmulti-stop
Multiple Airlines
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 August, where tickets cost C$ 216 (return) on average. On the other hand, the most expensive months are February and March, where the average cost of round-trip tickets is C$ 445 and C$ 391 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.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at C$ 203 on average.

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 16% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 17 weeks before departure.

Good to know

Low seasonJanuary
Best time to beat the crowds but there is an average 13% increase in price.
Most popular time to fly and prices are also 23% lower 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

  • 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 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$ 279 or less one-way.

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

Frontier,United Airlines

Frontier,United Airlines

Wednesday

Frontier,United Airlines

Frontier,United Airlines

Thursday

Frontier,United Airlines

Frontier,United Airlines

Friday

Frontier,United Airlines

Frontier,United Airlines

Saturday

Frontier,United Airlines

Frontier,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

Frontier,United Airlines

Frontier,United Airlines

Wednesday

Frontier,United Airlines

Frontier,United Airlines

Thursday

Frontier,United Airlines

Frontier,United Airlines

Friday

Frontier,United Airlines

Frontier,United Airlines

Saturday

Frontier,United Airlines

Frontier,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 9859 reviews
7.3Comfort
7.7Boarding
8.1Crew
7.1Entertainment
6.6Food
Airline reviews

Horrifying Almost 2 million miles. Bring your own food and drink. One coffee or drink every three hours. Have to order meals on app more than 24 hours ahead Tiny and dirty bathrooms

2.0 MediocreAnonymous, May 2026
SFO - TPA
Read more United Airlines reviews

Horrifying Almost 2 million miles. Bring your own food and drink. One coffee or drink every three hours. Have to order meals on app more than 24 hours ahead Tiny and dirty bathrooms

My service dog and I were asked to deplane just before they closed the door - clearly very last minute they couldn’t find the documentation that I have filled out many many times before that is for flying service animals. I purposely purchase 3seats (a whole row) since he is large and not all passengers want to sit next to a dog on a cross country flight. The plane departed with my husband on it!!! They made me fill out a hard copy of the same form and had to reschedule me on a later flight where they could find 3 seats together!! I’ve done this so many times before - clearly the error was on their part in a technology glitch - but really people - do better!! Very traumatic - and my husband had to wait for us when he landed ….so bad. Poor pup was confused and tired.

No screens or meal options. Freezing cold. Dirty seats. Left late.

Outstanding service, efficient & friendly crew, flight was safe, comfortable & on time

It was a red-eye, but the flight felt surprisingly quick. The seats were very comfortable, and that made resting much easier. I also want to thank the gentleman seated next to me, who graciously moved so my mom could sit beside me. We slept almost the entire way. The cabin crew was respectful in not disturbing us, while also being courteous and professional throughout. Thank you, United.

Boarding was again a "free for all". We were boarding group 4, and almost the entire plane was able to board before us. It's a shame that someone who follows the rules, gets the short end of the stick. Not fair.

It was perfect! I've never flown with United before, but I definitely will in the future

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.

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

Information on your arrival and departure airports