Find flights
Deals
When to book
FAQs

Cheap flights from Ontario to San Francisco from C$ 103

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 21/4. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
10 Apr — 17 Apr1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Ontario to San Francisco are usually found in May or April, booked 74 days in advance, depart on a Monday or Wednesday 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 11 March 2026.

Mon 18/56:00 a.m.
ONT
-
SFO
Nonstop1h 29m
United Airlines
Tue 19/59:23 p.m.
SFO
-
ONT
Nonstop1h 36m
United Airlines
Deal found 9/3C$ 186
Tue 21/43:45 p.m.
ONT
-
SFO
1 stop7h 00m
Southwest
Tue 28/45:55 a.m.
SFO
-
ONT
1 stop3h 55m
Southwest
Deal found 10/3C$ 205
Tue 31/311:05 a.m.
ONT
-
SFO
Nonstop1h 29m
United Airlines
Tue 31/34:25 p.m.
SFO
-
ONT
Nonstop1h 37m
United Airlines
Deal found 9/3C$ 206
Wed 1/46:49 p.m.
ONT
-
SFO
Nonstop1h 29m
United Airlines
Wed 8/49:09 p.m.
SFO
-
ONT
Nonstop1h 36m
United Airlines
Deal found 10/3C$ 213
Sat 28/36:15 a.m.
ONT
-
SFO
Nonstop1h 33m
United Airlines
Tue 31/38:25 a.m.
SFO
-
ONT
Nonstop1h 31m
United Airlines
Deal found 7/3C$ 227
Sat 4/41:27 p.m.
ONT
-
SFO
Nonstop1h 30m
United Airlines
Sat 4/49:09 p.m.
SFO
-
ONT
Nonstop1h 36m
United Airlines
Deal found 9/3C$ 235
Sat 18/45:40 a.m.
ONT
-
SFO
1 stop6h 10m
Southwest
Wed 22/45:40 a.m.
SFO
-
ONT
1 stop4h 25m
Southwest
Deal found 10/3C$ 236
Thu 16/46:00 a.m.
ONT
-
SFO
Nonstop1h 29m
United Airlines
Sat 18/410:50 a.m.
SFO
-
ONT
Nonstop1h 30m
United Airlines
Deal found 10/3C$ 240
Tue 14/43:45 p.m.
ONT
-
SFO
2 stops7h 30m
Southwest
Thu 16/45:05 a.m.
SFO
-
ONT
1 stop6h 15m
Southwest
Deal found 9/3C$ 243
Tue 14/41:27 p.m.
ONT
-
SFO
Nonstop1h 29m
United Airlines
Thu 16/410:50 a.m.
SFO
-
ONT
Nonstop1h 30m
United Airlines
Deal found 6/3C$ 247

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 11 March 2026.

Round-trip from

C$ 186

One-way from

C$ 103

Popular in

February

Cheapest in

May

Average price

C$ 242
United Airlines
  • United Airlines
  • 9/4-14/4
  • Nonstop
  • 3h 00m total
  • Ontario to San Francisco
Search Deals
Southwest
  • Southwest
  • 10/6
  • 1 total stop
  • 4h 40m total
  • Ontario to San Francisco
Search Deals
Highest demand for flights based on searches. 29% potential increase in price (C$ 134 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 7% potential price decrease (C$ 22 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
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 11 March 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 18/5

10:37 a.m.-12:07 p.m.

Nonstop1h 30m

San Francisco

Wed 20/5

4:15 p.m.-5:52 p.m.

Nonstop1h 37m

C$ 186

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/4

11:05 a.m.-12:35 p.m.

Nonstop1h 30m

San Francisco

Tue 14/4

10:50 a.m.-12:20 p.m.

Nonstop1h 30m

C$ 213

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 21/4

1:27 p.m.-2:56 p.m.

Nonstop1h 29m

San Francisco

Wed 22/4

4:10 p.m.-5:47 p.m.

Nonstop1h 37m

C$ 213

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 21/4

2:10 p.m.-10:45 p.m.

2 stops8h 35m

San Francisco

Mon 27/4

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

2 stops7h 00m

C$ 250

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/4

5:05 p.m.-9:10 p.m.

1 stop4h 05m

San Francisco

Wed 15/4

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

2 stops7h 20m

C$ 288

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 30/4

6:00 a.m.-7:29 a.m.

Nonstop1h 29m

San Francisco

Mon 4/5

4:15 p.m.-5:52 p.m.

Nonstop1h 37m

C$ 295

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 19/5

1:30 p.m.-3:00 p.m.

Nonstop1h 30m

San Francisco

Sun 24/5

10:40 a.m.-12:12 p.m.

Nonstop1h 32m

C$ 337

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 9/5

3:26 p.m.-9:23 p.m.

1 stop5h 57m

San Francisco

Wed 13/5

6:00 a.m.-11:58 p.m.

1 stop17h 58m

C$ 357
Quickest round-trip

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 18/4

6:00 a.m.-7:29 a.m.

Nonstop1h 29m

San Francisco

Sun 19/4

10:50 a.m.-12:20 p.m.

Nonstop1h 30m

C$ 364

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 24/4

1:27 p.m.-2:56 p.m.

Nonstop1h 29m

San Francisco

Mon 27/4

10:50 a.m.-12:20 p.m.

Nonstop1h 30m

C$ 365

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/3

Showing 1-10 of 22 resultsSorted by cheapest first
1
2
3

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 6 March 2026.

To ensure you get the cheapest price possible for a flight from Ontario to San Francisco, you should look to book at least 74 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, May is the cheapest month in which you can book a flight from Ontario to San Francisco (average of C$ 38). Flying from Ontario to San Francisco in November is currently the most expensive (average of C$ 84). 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 March 2026.

It’s typically best to fly out from Ontario to San Francisco in the evening. Doing so could potentially save you 84% 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?

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, 12 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 30m. 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 SkyWest Airlines (79%), Copa Airlines (78%) or United Airlines (73%) 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, May is the cheapest month in which you can book a flight from Ontario to San Francisco (average of C$ 38). Flying from Ontario to San Francisco in November is currently the most expensive (average of C$ 84). 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
Burlingame
South San Francisco
Scotts Valley
Novato
Santa Clara
Vallejo

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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 Ontario to San Francisco?

Cheapflights makes it easy to find Ontario to San Francisco 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 Ontario to San Francisco?

Millions of users choose and trust Cheapflights to book the best flight deals from Ontario to San Francisco for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

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

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

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

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.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.