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$29+ Cheap flights from Ontario to San Francisco (ONT - SFO)

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 4/26. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
Jan 25 — Feb 11
Sat 1/25
Sat 2/1
1 adult, Economy
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The best prices from Ontario to San Francisco are usually found in April or July, booked 63 days in advance, depart on a Tuesday or Monday and return on a Wednesday

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 January 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$38
(Frontier)

One-way from

$29
(Cheapflightsfares)

Popular in

February

Cheapest in

April

Average price

$142
Provider with most accurate pricing for Ontario-San Francisco flight deals.
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Provider most trusted by Cheapflights users for Ontario-San Francisco flights.
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From Ontario to San Francisco
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One-way flight from Ontario to San Francisco
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High demand for flights, 25% potential price rise
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Best time to find cheap flights, 5% potential price drop
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Average for round-trip flights in January 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 January 20, 2025.

This Frontier deal was found by Cheapflights users on 1/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/26:45 amONT - SFO
Nonstop1h 35mFrontier
Mon 2/39:59 pmSFO - ONT
Nonstop1h 25mFrontier
Deal found 1/19$38
This United Airlines deal was found by Cheapflights users on 1/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/76:00 amONT - SFO
Nonstop1h 29mUnited Airlines
Sat 3/89:15 pmSFO - ONT
Nonstop1h 30mUnited Airlines
Deal found 1/20$57
This American Airlines deal was found by Cheapflights users on 1/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/236:10 amONT - SFO
1 stop6h 20mAmerican Airlines
Sat 1/259:15 amSFO - ONT
1 stop6h 14mAmerican Airlines
Deal found 1/20$199
This Southwest deal was found by Cheapflights users on 1/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 1/289:20 amONT - SFO
1 stop5h 10mSouthwest
Wed 1/296:05 amSFO - ONT
2 stops7h 20mSouthwest
Deal found 1/19$212
This Orbitz deal was found by Cheapflights users on 1/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/77:00 amONT - SFO
2 stops8h 43mMultiple Airlines
Sun 3/98:16 amSFO - ONT
Nonstop1h 28mMultiple Airlines
Deal found 1/18$216

Find flights from Ontario to San Francisco within your budget

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 2,558,603 searches. Data last updated January 20, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 2/7

6:00 am-7:35 am

Nonstop1h 35m

San Francisco

Sun 2/9

9:59 pm-11:24 pm

Nonstop1h 25m

$38

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 2/27

6:00 am-7:29 am

Nonstop1h 29m

San Francisco

Sat 3/1

7:10 pm-8:40 pm

Nonstop1h 30m

$57

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 2/13

8:15 am-3:10 pm

1 stop6h 55m

San Francisco

Mon 2/17

5:20 am-1:05 pm

1 stop7h 45m

$157

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 3/7

7:00 am-3:43 pm

2 stops8h 43m

San Francisco

Sun 3/9

8:16 am-9:44 am

Nonstop1h 28m

$206

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 4/26

8:20 am-10:01 am

Nonstop1h 41m

$29

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 2/6

10:47 am-12:20 pm

Nonstop1h 33m

$59

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 1/29

6:35 pm-10:15 pm

1 stop3h 40m

$79

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 1/25

12:48 pm-6:59 pm

1 stop6h 11m

$100

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 2/11

6:00 am-4:07 pm

2 stops10h 07m

$107

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 3/22

6:00 am-10:23 pm

2 stops16h 23m

$243

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/20

Compare providers for flights from Ontario to San Francisco

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to San Francisco in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
Kiwi.comPrice Accuracy3 starsTrust Score*3 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*1 star
CheapOairPrice Accuracy2 starsTrust Score*2 stars
CheapTicketsDealPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Ontario-San Francisco flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-San Francisco flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-San Francisco flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-San Francisco flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-San Francisco flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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.

Travel insights for flights from Ontario to San Francisco

Get recent, data-driven insights about flights from Ontario to San Francisco including ideal travel times, pricing trends, and more.

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 January 17, 2025.

Booking 63 days in advance of your planned departure date is, on average, the best time to get cheap flights from Ontario to San Francisco. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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 $276). Flying from Ontario to San Francisco in June is currently the most expensive (average of $405). 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 January 20, 2025.

One of the essential ways to save on airfare from Ontario to San Francisco is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the morning could potentially save you up to 47% on airfare.

What is the cheapest day to fly from Ontario to San Francisco?

Use this chart to determine the cheapest time to fly round-trip from Ontario to San Francisco. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Ontario to San Francisco flight should consider departing on Tuesday evenings when fares are most often at their lowest. Friday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Ontario to San Francisco

Explore weekly flight availability from Ontario to San Francisco. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated January 20, 2025.

The most flights from ONT to SFO are scheduled on a Monday (9 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (5 on average).

Rainfall in San Francisco by month

Plan your trip to San Francisco by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in San Francisco ranges from 0.0 - 4.4 inches per month. January is typically the wettest month, when rainfall can reach 4.4 in. July is typically the driest time to visit San Francisco when rainfall is around 0.0 in.

Temperature in San Francisco by month

Plan your trip to San Francisco by taking into account the average temperature totals by month.

If weather is an important factor for your trip to San Francisco, use this chart to help with planning. For those seeking warmer temperatures, September is the ideal time of year to visit, when temperatures reach an average of 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 51.8 F).

Reviews of airlines servicing San Francisco

Get insights into the airlines that provide service to San Francisco. 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 San Francisco. Reviews last updated January 20, 2025.
Read reviews from past customers who have flown Frontier, United Airlines and Southwest from Ontario to San Francisco. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,659 reviews

Boarding

8.2

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

Southwest
8.1
Very good
4,659 reviews
Southwest
8.1
Very good
4,659 reviews

Boarding

8.2

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

Alaska Airlines
8.0
Very good
9,696 reviews
Southwest
8.1
Very good
4,659 reviews

Boarding

8.2

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

Delta
8.0
Very good
8,521 reviews
Southwest
8.1
Very good
4,659 reviews

Boarding

8.2

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

United Airlines
7.4
Good
8,982 reviews
Southwest
8.1
Very good
4,659 reviews

Boarding

8.2

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,659 reviews

Boarding

8.2

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Overall

8.1

Reviews

1 / 10

No issues. I needed pre boarding and I was able to get it without issue

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.

  • What airports do I use to fly from Ontario to San Francisco?

    To fly from Ontario to San Francisco, you need to book a flight from Ontario (ONT) to San Francisco (SFO). Nonstop flights to San Francisco from Ontario take 1h 27m on average. When it comes time to book airfare, you have a few options: there are 6 outbound flights from Ontario to San Francisco offered by 6 different airlines.

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

    This flight path from Ontario to San Francisco was viewed by 184 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • What are the cheapest airlines flying from Ontario to San Francisco round-trip?

    Flying on Frontier is currently your cheapest option to San Francisco, with prices starting at $38. Additional round-trip tickets that might be worth considering are offered by United Airlines and Southwest, with the lowest prices starting at $57 and $202, respectively. You may be able to fly from Ontario to San Francisco for 67% less than the average price by searching for these airlines.

  • What are the cheapest airlines to fly from Ontario to San Francisco one-way?

    The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $29. However, be on the lookout for offers from United Airlines and Southwest, as they are both options that can get you from Ontario to San Francisco for a low price.

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

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Ontario to San Francisco on time: Air Canada (72%), SkyWest Airlines (70%), Copa Airlines (69%).

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

    On average you can expect to pay $756 for a flight from Ontario to San Francisco. The cheapest flight overall is $26 while the most popular route, (Ontario - San Francisco) is currently priced at $38.

  • 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 $276). Flying from Ontario to San Francisco in June is currently the most expensive (average of $405). 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

Traveling to a place near Ontario?

Book flights to Ontario if you plan to visit one of these locations
Mountain View
Roseville
Turlock
Santa Cruz
Fairfield
Manteca
Sausalito
Watsonville
Hayward
Richmond
Hollister
Antioch
South San Francisco
Milpitas
Elk Grove
Newark
Alameda
Campbell
Lathrop
Pacific Grove

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Top 6 airlines flying from Ontario to San Francisco

Discover the top 6 airlines that operate flights from Ontario to San Francisco. 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 2,558,603 searches. Data last updated January 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$31Average$65FlexibilityNo cancel feeOn-time65%
FrontierCheapest$38Average$86FlexibilityNo cancel feeOn-time62%
Breeze AirwaysCheapest$78Average$135FlexibilityNo cancel feeOn-timeN/A
DeltaCheapest$85Average$196FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$108Average$162FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$117Average$258FlexibilityNo cancel feeOn-time69%
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