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Cheap flights from Ontario to San Francisco from C$ 41

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 7/9. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
26 Aug — 2 Sep1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Ontario to San Francisco are usually found in October or September, booked 54 days in advance, depart on a Monday or Tuesday and return on a Monday

Cheap flight deals from Ontario to San Francisco

Enter your travel dates to find the best prices.

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 27 July 2026.

Wed 19/89:01 a.m.
ONT
-
SFO
Nonstop1h 29m
United Airlines
Wed 2/94:45 p.m.
SFO
-
ONT
Nonstop1h 31m
United Airlines
Deal found 24/7C$ 165
Tue 1/126:00 a.m.
ONT
-
SFO
Nonstop1h 29m
United Airlines
Thu 3/129:30 p.m.
SFO
-
ONT
Nonstop1h 36m
United Airlines
Deal found 25/7C$ 178
Sat 26/98:03 a.m.
ONT
-
SFO
Nonstop1h 27m
United Airlines
Mon 28/910:43 a.m.
SFO
-
ONT
Nonstop1h 35m
United Airlines
Deal found 22/7C$ 193
Fri 18/912:07 p.m.
ONT
-
SFO
Nonstop1h 36m
Frontier
Mon 21/96:02 p.m.
SFO
-
ONT
Nonstop1h 34m
Frontier
Deal found 25/7C$ 194
Tue 11/81:38 p.m.
ONT
-
SFO
1 stop7h 34m
Frontier
Mon 17/89:33 a.m.
SFO
-
ONT
Nonstop1h 29m
Frontier
Deal found 25/7C$ 201
Sat 22/82:55 p.m.
ONT
-
SFO
1 stop3h 25m
Southwest
Tue 25/84:45 p.m.
SFO
-
ONT
1 stop4h 10m
Southwest
Deal found 27/7C$ 213
Thu 20/811:15 a.m.
ONT
-
SFO
1 stop5h 21m
Frontier
Mon 24/89:33 a.m.
SFO
-
ONT
Nonstop1h 29m
Frontier
Deal found 24/7C$ 216
Sat 22/811:00 a.m.
ONT
-
SFO
2 stops6h 30m
Southwest
Mon 24/85:10 a.m.
SFO
-
ONT
1 stop6h 15m
Southwest
Deal found 27/7C$ 220
Wed 19/88:35 a.m.
ONT
-
SFO
1 stop4h 40m
Southwest
Sat 22/85:00 a.m.
SFO
-
ONT
1 stop3h 45m
Southwest
Deal found 24/7C$ 221
Fri 30/105:30 a.m.
ONT
-
SFO
1 stop4h 35m
Southwest
Mon 2/113:15 p.m.
SFO
-
ONT
1 stop6h 40m
Southwest
Deal found 27/7C$ 231

Find 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 27 July 2026.

Round-trip from

C$ 165

One-way from

C$ 41

Popular in

February

Cheapest in

October

Average price

C$ 317

Good round-trip deal

C$ 679 or less

Good one-way deal

C$ 266 or less
United Airlines
  • United Airlines
  • 5/9-9/9
  • Nonstop
  • 2h 58m total
  • Ontario to San Francisco
Search Deals
Frontier
  • Frontier
  • 7/9
  • Nonstop
  • 1h 27m total
  • Ontario to San Francisco
Search Deals
Highest demand for flights based on searches. 20% potential increase in price (C$ 111 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (C$ 17 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2026
Search Deals
Price to beat on a round-trip flight from Ontario to San Francisco.
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Price to beat on a one-way flight from Ontario to San Francisco.
Search Deals

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 27 July 2026.
Use the filters below to find and compare flights from Ontario to San Francisco that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Mon 24/8

2:40 p.m.-9:40 p.m.

2 stops7h 00m

San Francisco

Mon 31/8

11:05 a.m.-3:15 p.m.

1 stop4h 10m

C$ 220

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Mon 24/8

4:50 p.m.-11:05 p.m.

1 stop6h 15m

San Francisco

Tue 25/8

2:35 p.m.-8:55 p.m.

2 stops6h 20m

C$ 220

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 28/10

5:00 p.m.-10:45 p.m.

1 stop5h 45m

San Francisco

Sat 31/10

8:10 a.m.-12:45 p.m.

1 stop4h 35m

C$ 221

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 1/9

5:45 a.m.-1:15 p.m.

2 stops7h 30m

San Francisco

Tue 1/9

2:35 p.m.-8:55 p.m.

2 stops6h 20m

C$ 227

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 22/8

10:15 a.m.-6:20 p.m.

2 stops8h 05m

San Francisco

Mon 24/8

2:50 p.m.-10:05 p.m.

2 stops7h 15m

C$ 227

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 18/8

1:10 p.m.-7:05 p.m.

2 stops5h 55m

San Francisco

Thu 20/8

5:10 a.m.-1:25 p.m.

2 stops8h 15m

C$ 249
Quickest round-trip

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 7/10

1:52 p.m.-3:21 p.m.

Nonstop1h 29m

San Francisco

Thu 8/10

9:25 p.m.-10:51 p.m.

Nonstop1h 26m

C$ 335

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 10/10

3:10 p.m.-9:35 p.m.

1 stop6h 25m

San Francisco

Sun 11/10

5:00 a.m.-9:05 a.m.

1 stop4h 05m

C$ 345

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 20/8

5:15 a.m.-1:10 p.m.

2 stops7h 55m

San Francisco

Sat 22/8

5:00 a.m.-11:15 a.m.

2 stops6h 15m

C$ 349

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 23/10

1:30 p.m.-6:45 p.m.

2 stops5h 15m

San Francisco

Wed 28/10

5:20 a.m.-3:40 p.m.

2 stops10h 20m

C$ 359

Flights are sorted by cheapest round-trip flights first.

Deals found on 24/7

Showing 1-10 of 23 resultsSorted by cheapest first
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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?

To ensure you get the cheapest price possible for a flight from Ontario to San Francisco, you should look to book at least 53 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, October is the cheapest month in which you can book a flight from Ontario to San Francisco (average of C$ 199). Flying from Ontario to San Francisco in February is currently the most expensive (average of C$ 431). 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 27 July 2026.

It’s typically best to fly out from Ontario to San Francisco in the evening. Doing so could potentially save you 93% on the flight price compared to flying in the afternoon, which is usually more expensive.

How much does it cost to fly round-trip from Ontario to San Francisco?

Airfare is typical for this route at the moment.

Ontario to San Francisco flights typically cost between C$ 154 and C$ 344 in August.
The cheapest round-trip price found within the last 5 days was C$ 165 on United Airlines (19 Aug-2 Sep).

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, 3 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 27m. 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 Air Canada (35%), United Airlines (31%) or Copa Airlines (22%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Ontario to San Francisco?

    While on average a flight from Ontario to San Francisco is generally C$ 593, our data shows the cheapest flight currently is C$ 265. When looking at the most popular route, (Ontario - San Francisco), you can expect to pay C$ 265 for that flight.

  • 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, October is the cheapest month in which you can book a flight from Ontario to San Francisco (average of C$ 199). Flying from Ontario to San Francisco in February is currently the most expensive (average of C$ 431). 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
Santa Clara
Burlingame
San Bruno
Roseville
Livermore
South San Francisco
Novato
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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