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Cheap flights from San Francisco to Ontario

SFO — ONT
15 Oct — 22 Oct1
1 adult
1 adult, Economy

Cheap flight deals from San Francisco to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from San Francisco (SFO) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 15 September 2025.

Popular in

December

Cheapest in

February

Average price

C$ 189
Highest demand for flights based on searches. 11% potential increase in price (C$ 37 potential increase over avg. RT price).
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Cheapest flight prices on average. 6% potential price decrease (C$ 17 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Best time to book a flight from San Francisco to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from San Francisco with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

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

Use this chart to determine the optimal time to book a round-trip flight from San Francisco to Ontario. Price data was last updated on 12 September 2025.

The best time to book flights from San Francisco to Ontario is 89 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from San Francisco to Ontario?

Currently, September is the cheapest month in which you can book a flight from San Francisco to Ontario (average of C$ 290). Flying from San Francisco to Ontario in December is currently the most expensive (average of C$ 461). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SFO to ONT?

Find hourly flight availability from San Francisco to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 15 September 2025.

One of the essential ways to save on airfare from San Francisco to Ontario is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at noon could potentially save you up to 16% on airfare.

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated 15 September 2025.
Get a feel of what it's like to fly with United Airlines from San Francisco to Ontario by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,929 reviews
Check prices

Crew

8.1

Overall

7.4

Boarding

7.7

Entertainment

7.1

Comfort

7.3

Food

6.6

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
United Airlines
7.4
Good
8,929 reviews
United Airlines
7.4
Good
8,929 reviews
Check prices

Crew

8.1

Overall

7.4

Boarding

7.7

Entertainment

7.1

Comfort

7.3

Food

6.6

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??

Related info for your journey

Find useful and relevant information for your journey from San Francisco to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How popular is this San Francisco to Ontario flight route?

    Flights from San Francisco to Ontario have been viewed 16 times in the past calendar month.

  • What is the cheapest airline to fly from San Francisco to Ontario round-trip?

    According to our current data, United Airlines (C$ 369), offers the cheapest pricing from San Francisco to Ontario.

  • What are the most reliable airlines from San Francisco to Ontario?

    Consider SkyWest Airlines (83%), United Airlines (82%) or Air Canada (79%) when booking your flight. These represent the most reliable airlines when flying from San Francisco to Ontario.

  • Can I find deals for flights from San Francisco to Ontario that include hotel bookings?

    Yes. In addition to deals on San Francisco to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from San Francisco to Ontario?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from San Francisco to Ontario.

  • Can I find deals for business class flights from San Francisco to Ontario?

    Yes. Cheapflights offers flight deals from San Francisco to Ontario by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

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

    Currently, September is the cheapest month in which you can book a flight from San Francisco to Ontario (average of C$ 290). Flying from San Francisco to Ontario in December is currently the most expensive (average of C$ 461). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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Browse thousands of different options on Cheapflights for your next trip

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Top airline flying from San Francisco to Ontario

Discover the top airline that operate flights from San Francisco to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 629,999 searches. Data last updated 15 September 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapestC$ 369AverageC$ 438FlexibilityNo cancel feeOn-time69%
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Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from San Francisco to Ontario?

Cheapflights makes it easy to find San Francisco to Ontario flights by helping our users search from 900+ travel sites for deals. We also provide you with filters for cabin, price, airline, airports, number of stops, and many more to narrow down that perfect flight.

Why should you use Cheapflights to find cheap flight tickets from San Francisco to Ontario?

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from San Francisco to Ontario for you. Better yet — we are completely free to use.

Can Cheapflights find flights from San Francisco to Ontario with no change fees?

Yes! Cheapflights helps users easily find flights from San Francisco to Ontario with no change fees.

Can Cheapflights notify me if prices for flights from San Francisco to Ontario become cheaper?

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

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