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Cheap flights from Ontario to San Francisco from C$ 54

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 19/11. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
11 Oct — 18 Oct1
1 adult
1 adult, Economy

Cheapflights Tip: The best prices from Ontario to San Francisco are usually found in May or February, booked 89 days in advance, depart on a Thursday or Monday and return on a Monday

Cheap flight deals from Ontario to San Francisco

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to San Francisco (SFO). 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 11 September 2025.

Round-trip from

C$ 107

One-way from

C$ 54

Popular in

November

Cheapest in

May

Average price

C$ 148
United Airlines
  • United Airlines
  • 1/11-3/11
  • Nonstop
  • 2h 46m total
  • Ontario to San Francisco
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United Airlines
  • United Airlines
  • 19/11
  • Nonstop
  • 1h 24m total
  • Ontario to San Francisco
Search Deals
Highest demand for flights based on searches. 8% potential increase in price (C$ 20 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 7 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Ontario to San Francisco

Cheapest flights from Ontario to San Francisco
Explore the most affordable flight options available from Ontario to San Francisco. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 11 September 2025.

Sat 1/116:38 p.m.ONT - SFO
Nonstop1h 24mUnited Airlines
Mon 3/1111:15 a.m.SFO - ONT
Nonstop1h 22mUnited Airlines
Deal found 10/9C$ 107
Thu 6/116:00 a.m.ONT - SFO
Nonstop1h 24mUnited Airlines
Sat 8/119:30 p.m.SFO - ONT
Nonstop1h 21mUnited Airlines
Deal found 11/9C$ 141
Mon 29/98:59 p.m.ONT - SFO
1 stop25h 31mFrontier
Thu 2/1010:11 p.m.SFO - ONT
Nonstop1h 27mFrontier
Deal found 11/9C$ 144
Thu 23/109:36 a.m.ONT - SFO
Nonstop1h 19mUnited Airlines
Sun 26/109:30 p.m.SFO - ONT
Nonstop1h 21mUnited Airlines
Deal found 9/9C$ 151
Sat 27/96:51 p.m.ONT - SFO
Nonstop1h 19mUnited Airlines
Sat 27/99:30 p.m.SFO - ONT
Nonstop1h 22mUnited Airlines
Deal found 11/9C$ 155
Fri 24/109:36 a.m.ONT - SFO
Nonstop1h 19mUnited Airlines
Sun 26/109:30 p.m.SFO - ONT
Nonstop1h 21mUnited Airlines
Deal found 11/9C$ 159
Thu 25/91:53 p.m.ONT - SFO
Nonstop1h 18mUnited Airlines
Sat 27/99:30 p.m.SFO - ONT
Nonstop1h 22mUnited Airlines
Deal found 11/9C$ 162
Tue 7/104:25 p.m.ONT - SFO
1 stop6h 20mSouthwest
Wed 8/105:30 a.m.SFO - ONT
1 stop5h 05mSouthwest
Deal found 11/9C$ 168
Thu 25/91:53 p.m.ONT - SFO
Nonstop1h 18mUnited Airlines
Thu 25/94:20 p.m.SFO - ONT
Nonstop1h 20mUnited Airlines
Deal found 11/9C$ 182
Wed 12/116:00 a.m.ONT - SFO
Nonstop1h 24mUnited Airlines
Wed 12/1111:15 a.m.SFO - ONT
Nonstop1h 22mUnited Airlines
Deal found 10/9C$ 183
Tue 7/109:36 a.m.ONT - SFO
Nonstop1h 19mUnited Airlines
Wed 8/1010:45 a.m.SFO - ONT
Nonstop1h 28mUnited Airlines
Deal found 11/9C$ 187
Wed 1/101:53 p.m.ONT - SFO
Nonstop1h 18mUnited Airlines
Mon 6/109:30 p.m.SFO - ONT
Nonstop1h 22mUnited Airlines
Deal found 10/9C$ 190

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to San Francisco that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 629,999 searches. Data last updated 11 September 2025.
Use the filters below to find and compare flights from Ontario to San Francisco that are best for you.

Fly from

Ontario

Fly to

San Francisco

Route

Depart

Return

Price

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Mon 6/10

9:36 a.m.-10:55 a.m.

Nonstop1h 19m

San Francisco

Mon 10/11

9:30 p.m.-10:51 p.m.

Nonstop1h 21m

C$ 162

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 26/9

1:53 p.m.-3:11 p.m.

Nonstop1h 18m

San Francisco

Sat 27/9

9:30 p.m.-10:52 p.m.

Nonstop1h 22m

C$ 162

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 24/9

1:42 p.m.-3:01 p.m.

Nonstop1h 19m

San Francisco

Fri 26/9

9:30 p.m.-10:52 p.m.

Nonstop1h 22m

C$ 162

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 12/11

6:00 a.m.-7:24 a.m.

Nonstop1h 24m

San Francisco

Wed 12/11

11:15 a.m.-12:37 p.m.

Nonstop1h 22m

C$ 183

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 4/10

9:36 a.m.-10:55 a.m.

Nonstop1h 19m

San Francisco

Tue 11/11

11:15 a.m.-12:37 p.m.

Nonstop1h 22m

C$ 190

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 2/10

1:53 p.m.-3:11 p.m.

Nonstop1h 18m

San Francisco

Tue 7/10

10:45 a.m.-12:13 p.m.

Nonstop1h 28m

C$ 190

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 7/10

1:53 p.m.-3:11 p.m.

Nonstop1h 18m

San Francisco

Tue 11/11

11:15 a.m.-12:37 p.m.

Nonstop1h 22m

C$ 190

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 15/11

6:38 p.m.-8:02 p.m.

Nonstop1h 24m

San Francisco

Mon 17/11

9:30 p.m.-10:51 p.m.

Nonstop1h 21m

C$ 190

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/10

6:36 p.m.-7:55 p.m.

Nonstop1h 19m

San Francisco

Sat 11/10

10:45 a.m.-12:13 p.m.

Nonstop1h 28m

C$ 190

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 2/10

1:53 p.m.-3:11 p.m.

Nonstop1h 18m

San Francisco

Mon 6/10

9:30 p.m.-10:52 p.m.

Nonstop1h 22m

C$ 190

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/9

Showing 1-10 of 24 results
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Best time to book a flight from Ontario to San Francisco

Have a flexible travel schedule? Discover the best time to fly to San Francisco from Ontario 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 Ontario to San Francisco

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

Use this chart to determine the optimal time to book a round-trip flight from Ontario to San Francisco. Price data was last updated on 29 August 2025.

To ensure you get the cheapest price possible for a flight from Ontario to San Francisco, you should look to book at least 89 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, January is the cheapest month in which you can book a flight from Ontario to San Francisco (average of C$ 276). Flying from Ontario to San Francisco in December is currently the most expensive (average of C$ 368). 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 ONT to SFO?

Find hourly flight availability from Ontario to San Francisco. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 11 September 2025.

It’s typically best to fly out from Ontario to San Francisco at noon. Doing so could potentially save you 19% on the flight price compared to flying in the morning, which is usually more expensive.

Related info for your journey

Find useful and relevant information for your journey from Ontario to San Francisco. 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 Ontario to San Francisco flight route?

    Within the past month, 24 users have taken a look at flights from Ontario to San Francisco.

  • How long is the flight from Ontario to San Francisco?

    There are many flights that can get you from Ontario to San Francisco in 1h 24m. Fly via United Airlines or Southwest to get the fastest option. The distance from Ontario to San Francisco is about 584 km. This flight may include one or multiple stops.

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

    No one likes to see their flight delayed. When booking a flight from Ontario to San Francisco consider choosing Emirates (87%), SkyWest Airlines (83%) or Air Canada (77%) as they are the most reliable in getting you off to your destination on time.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Ontario to San Francisco 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 Ontario to San Francisco?

    Currently, January is the cheapest month in which you can book a flight from Ontario to San Francisco (average of C$ 276). Flying from Ontario to San Francisco in December is currently the most expensive (average of C$ 368). 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.

See more FAQs

Travelling to a place near San Francisco?

Book flights to San Francisco if you plan to visit one of these locations
Richmond
Newark
Alameda
Redwood City
Burlingame
San Bruno
South San Francisco
Scotts Valley
Belmont
Novato
Millbrae
Santa Clara
Vallejo

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Users can book flights with no change fees policies with our dedicated filters. Book flights from Ontario to San Francisco flexibly with Cheapflights today.

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Not ready to book yet? You can track prices for flights from Ontario to San Francisco on Cheapflights with our Price Alert feature and get notified when better prices are available.

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