How popular is this Ontario to San Francisco flight route?

This flight path from Ontario to San Francisco was viewed by 192 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 $56. Additional round-trip tickets that might be worth considering are offered by United Airlines and Southwest, with the lowest prices starting at $112 and $196, respectively. You may be able to fly from Ontario to San Francisco for 47% 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 $37. 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 cheapest flights from Ontario to San Francisco?

On average you can expect to pay $762 for a flight from Ontario to San Francisco. The cheapest flight overall is $28 while the most popular route, (Ontario - San Francisco) is currently priced at $52.

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: Copa Airlines (87%), United Airlines (84%), SkyWest Airlines (83%).

What are the most popular airlines that fly from Ontario to San Francisco?

Before booking your flight from Ontario to San Francisco check out the most popular airlines for this route: Alaska Airlines, Delta or Frontier.

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

Users have found that flying from Ontario to San Francisco on a Tuesday typically leans towards higher prices. However, this doesn’t mean you still can’t find a deal. Flexibility with other aspects of your flight can still land a great price for your trip.

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

When searching for a good deal, it’s best to be prepared for potential fluctuations in price. We recommend booking at least 36 days in advance, which can save you up to 77% on flights from Ontario to San Francisco compared to booking the week you need them. Waiting 36 days out may not be for everyone, so we have options available for flights within the next two weeks, with the lowest price starting at $117. For sooner than that we have options available in the next 3 days from $179.

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

October can be a great time to fly to San Francisco from Ontario with a flight ticket averaging about $134. Cheapflights users have found deals in the month of October for as cheap as $34. The most expensive prices can be found in the month of April.

Most accurate provider : When it comes to deals on Ontario-San Francisco flights, users find the pricing of Mytrip to be most consistent on Cheapflights vs. Mytrip Users can find the same prices on Ontario-San Francisco flight deals on Cheapflights vs. Mytrip >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 Mytrip the most. Mytrip 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.

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 19m on average. When it comes time to book airfare, you have a few options: there are 4 outbound flights from Ontario to San Francisco offered by 7 different airlines.

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.

$37+ Flights from Ontario to San Francisco - Compare & Save Big

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Find cheap flights from Ontario to San Francisco with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Ontario to San Francisco are usually found in July or May, booked 87 days in advance, depart on a Friday or Saturday and return on a Monday

Cheap flight deals from Ontario to San Francisco

Most accurate provider	Mytrip 3 stars
Most trusted provider	Mytrip 3 stars
Round-trip from	$56 (Cheapflightsfares)
One-way from	$37 (Cheapflightsfares)
Popular in	November
Cheapest in	July
Average price	$120
Good round-trip deal	$91 or less
Good one-way deal	$58 or less

Provider with most accurate pricing for Ontario-San Francisco flight deals.

Search Deals

Provider most trusted by Cheapflights users for Ontario-San Francisco flights.

Search Deals

From Ontario to San Francisco

Search Deals

One-way flight from Ontario to San Francisco

Search Deals

Highest demand for flights based on searches. 16% potential increase in price ($20 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 3% potential price decrease ($4 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in April 2025

Search Deals

Price to beat on a round-trip flight from Ontario to San Francisco.

Search Deals

Price to beat on a one-way flight from Ontario to San Francisco.

Search Deals

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 April 29, 2025.

Fri 5/98:24 amONT - SFO

Nonstop1h 38mFrontier

Sat 5/1010:48 amSFO - ONT

Nonstop1h 27mFrontier

Deal found 4/28

$56

Wed 5/216:00 amONT - SFO

Nonstop1h 27mUnited Airlines

Thu 5/2210:45 amSFO - ONT

Nonstop1h 29mUnited Airlines

Deal found 4/28

$91

Wed 5/2111:51 amONT - SFO

1 stop7h 19mMultiple Airlines

Thu 5/2210:11 pmSFO - ONT

Nonstop1h 25mMultiple Airlines

Deal found 4/28

$195

Thu 5/297:35 pmONT - SFO

1 stop3h 50mSouthwest

Tue 6/35:40 amSFO - ONT

1 stop5h 20mSouthwest

Deal found 4/28

$196

Thu 5/14:35 pmONT - SFO

1 stop6h 04mAmerican Airlines

Fri 5/93:50 pmSFO - ONT

1 stop6h 07mAmerican Airlines

Deal found 4/28

$199

Best flights from Ontario to San Francisco
Discover carefully curated flight deals from Ontario to San Francisco that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 29, 2025.

Fri 5/98:24 amONT - SFO

Nonstop1h 38mFrontier

Sat 5/1010:48 amSFO - ONT

Nonstop1h 27mFrontier

Deal found 4/28

$56

Sat 7/126:10 amONT - SFO

Nonstop1h 27mUnited Airlines

Sat 7/1210:45 amSFO - ONT

Nonstop1h 29mUnited Airlines

Deal found 4/28

$112

Thu 6/128:05 pmONT - SFO

1 stop3h 20mSouthwest

Tue 6/175:25 amSFO - ONT

1 stop5h 35mSouthwest

Deal found 4/28

$196

Thu 5/14:35 pmONT - SFO

1 stop6h 04mAmerican Airlines

Sat 5/37:50 amSFO - ONT

1 stop4h 09mAmerican Airlines

Deal found 4/28

$199

Last-minute flights from Ontario to San Francisco
Discover last-minute flight deals from Ontario to San Francisco. Data last updated April 29, 2025 and is based on user searches.

Thu 5/14:35 pmONT - SFO

1 stop6h 04mAmerican Airlines

Fri 5/93:50 pmSFO - ONT

1 stop6h 07mAmerican Airlines

Deal found 4/28

$199

Sat 5/37:25 pmONT - SFO

1 stop4h 33mAmerican Airlines

Sun 5/45:55 amSFO - ONT

1 stop6h 04mAmerican Airlines

Deal found 4/27

$199

Mon 5/510:40 pmONT - SFO

1 stop13h 21mJetBlue

Thu 5/86:00 amSFO - ONT

1 stop15h 11mJetBlue

Deal found 4/28

$1,285

Tue 5/61:45 pmONT - SFO

Nonstop1h 28mUnited Airlines

Mon 5/127:05 pmSFO - ONT

Nonstop1h 29mUnited Airlines

Deal found 4/28

$127

Tue 5/61:20 pmONT - SFO

1 stop5h 01mDelta

Tue 5/136:05 amSFO - ONT

2 stops10h 12mDelta

Deal found 4/28

$1,462

Wed 5/73:40 pmONT - SFO

2 stops7h 00mSouthwest

Wed 5/145:15 amSFO - ONT

2 stops8h 45mSouthwest

Deal found 4/28

$237

Wed 5/79:56 amONT - SFO

1 stop6h 45mAlaska Airlines

Mon 5/127:59 pmSFO - ONT

1 stop13h 17mAlaska Airlines

Deal found 4/28

$507

Wed 5/73:10 pmONT - SFO

Nonstop1h 43mMultiple Airlines

Wed 5/148:00 amSFO - ONT

1 stop15h 58mMultiple Airlines

Deal found 4/28

$540

Thu 5/88:24 amONT - SFO

Nonstop1h 38mFrontier

Sat 5/1010:48 amSFO - ONT

Nonstop1h 27mFrontier

Deal found 4/28

$57

Fri 5/98:24 amONT - SFO

Nonstop1h 38mFrontier

Sat 5/1010:48 amSFO - ONT

Nonstop1h 27mFrontier

Deal found 4/28

$56

Wed 5/216:00 amONT - SFO

Nonstop1h 27mUnited Airlines

Thu 5/2210:45 amSFO - ONT

Nonstop1h 29mUnited Airlines

Deal found 4/28

$91

Wed 5/2111:51 amONT - SFO

1 stop7h 19mMultiple Airlines

Thu 5/2210:11 pmSFO - ONT

Nonstop1h 25mMultiple Airlines

Deal found 4/28

$195

One-way flights from Ontario to San Francisco
Search for one-way flight options from Ontario to San Francisco. Find affordable one-way fares based on user searches. Data last updated April 29, 2025.

Mon 5/269:41 pmONT - SFO

Nonstop1h 30mFrontier

Deal found 4/28

$37

Sat 7/126:10 amONT - SFO

Nonstop1h 27mUnited Airlines

Deal found 4/28

$59

Tue 6/105:25 pmONT - SFO

1 stop6h 00mSouthwest

Deal found 4/28

$76

Fri 5/210:00 amONT - SFO

1 stop6h 09mAmerican Airlines

Deal found 4/28

$100

Wed 5/214:45 pmONT - SFO

1 stop6h 59mAlaska Airlines

Deal found 4/28

$141

Tue 5/276:00 amONT - SFO

1 stop18h 04mDelta

Deal found 4/27

$147

Cheapflights Fare Finder

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

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 5/9

8:24 am-10:02 am

Nonstop1h 38m

San Francisco

Sat 5/10

10:48 am-12:15 pm

Nonstop1h 27m

$56

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 5/21

6:00 am-7:27 am

Nonstop1h 27m

San Francisco

Thu 5/22

10:45 am-12:14 pm

Nonstop1h 29m

$91

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 5/21

11:51 am-7:10 pm

1 stop7h 19m

San Francisco

Thu 5/22

10:11 pm-11:36 pm

Nonstop1h 25m

$195

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 5/29

7:35 pm-11:25 pm

1 stop3h 50m

San Francisco

Tue 6/3

5:40 am-11:00 am

1 stop5h 20m

$196

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 5/9

6:01 am-12:55 pm

1 stop6h 54m

San Francisco

Sun 5/11

12:04 pm-6:23 pm

1 stop6h 19m

$199

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Mon 5/26

9:41 pm-11:11 pm

Nonstop1h 30m

$37

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 7/16

6:39 pm-8:06 pm

Nonstop1h 27m

$59

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 5/13

3:40 pm-10:15 pm

1 stop6h 35m

$76

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 5/28

1:14 pm-6:58 pm

1 stop5h 44m

$100

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 5/28

6:00 am-5:00 pm

2 stops11h 00m

$137

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/28

Showing 1-10 of 11 results

Compare providers for flights from Ontario to San Francisco

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 April.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy1 star	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*2 stars
eDreams	Price Accuracy3 stars	Trust Score*3 stars
Cheapflightsfares	Price Accuracy3 stars	Trust Score*2 stars
Kiwi.com	Price Accuracy3 stars	Trust Score*3 stars
Mytrip	Price Accuracy3 stars	Trust Score*3 stars
CheapTicketsDeal	Price Accuracy3 stars	Trust Score*3 stars
JustAirTicket	Price Accuracy-	Trust Score*3 stars
Cheapfaremart	Price 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 Mytrip to be most consistent on Cheapflights vs. Mytrip Users can find the same prices on Ontario-San Francisco flight deals on Cheapflights vs. Mytrip >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 Mytrip the most. Mytrip 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.

The best insider tips for Ontario to San Francisco flights

Cheapflights partnered with top experts to bring you the best recommendations for your Ontario to San Francisco trip

Airlines

Frontier

Frontier's UpFront Plus guarantees an empty middle seat for extra comfort.

Early check-in helps secure your place onboard due to frequent overbooking.

Read more about Frontierby Marisa Garcia

United Airlines

Basic Economy allows a personal item only; no carry-on bags without extra fees.

Economy Plus offers extra legroom seats towards the front of the economy cabin.

Read more about United Airlinesby Harriet Baskas

Our travel experts

Marisa Garcia

Expert on Frontier

Harriet Baskas

Expert on United Airlines

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?

Booking 87 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 $393). 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?

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 evening could potentially save you up to 64% on airfare.

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

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. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Rainfall in San Francisco 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

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

Read reviews from past customers who have flown Alaska Airlines, Southwest and Delta 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.

Alaska Airlines

8.0

Very good

9,949 reviews

Reviews

1 / 20

10.0

Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot

Alaska Airlines

8.0

Very good

9,949 reviews

Alaska Airlines

8.0

Very good

9,949 reviews

Reviews

1 / 20

10.0

Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot

Southwest

8.0

Very good

4,292 reviews

Alaska Airlines

8.0

Very good

9,949 reviews

Reviews

1 / 20

10.0

Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot

Delta

8.0

Very good

7,929 reviews

Alaska Airlines

8.0

Very good

9,949 reviews

Reviews

1 / 20

10.0

Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot

United Airlines

7.4

Good

8,696 reviews

Alaska Airlines

8.0

Very good

9,949 reviews

Reviews

1 / 20

10.0

Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot

American Airlines

7.2

Good

10,000 reviews

Alaska Airlines

8.0

Very good

9,949 reviews

Reviews

1 / 20

10.0

Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot

Related info for your journey

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 19m on average. When it comes time to book airfare, you have a few options: there are 4 outbound flights from Ontario to San Francisco offered by 7 different airlines.
How popular is this Ontario to San Francisco flight route?
This flight path from Ontario to San Francisco was viewed by 192 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 $56. Additional round-trip tickets that might be worth considering are offered by United Airlines and Southwest, with the lowest prices starting at $112 and $196, respectively. You may be able to fly from Ontario to San Francisco for 47% 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 $37. 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: Copa Airlines (87%), United Airlines (84%), SkyWest Airlines (83%).
What are the cheapest flights from Ontario to San Francisco?
On average you can expect to pay $762 for a flight from Ontario to San Francisco. The cheapest flight overall is $28 while the most popular route, (Ontario - San Francisco) is currently priced at $52.
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 $393). 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

Roseville

Mountain View

Santa Cruz

Turlock

Livermore

South San Francisco

Fairfield

Manteca

Richmond

Watsonville

Hollister

Milpitas

Antioch

Sausalito

Vallejo

Newark

Hayward

Alameda

Sunnyvale

Campbell

Browse thousands of different options on Cheapflights for your next trip

Top 7 airlines flying from Ontario to San Francisco

Airline	Cheapest	Average	Flexibility	On-time
Spirit Airlines	Cheapest$31	Average$73	FlexibilityNo cancel fee	On-time65%
Frontier	Cheapest$36	Average$81	FlexibilityNo cancel fee	On-time62%
United Airlines	Cheapest$60	Average$227	FlexibilityNo cancel fee	On-time69%
Alaska Airlines	Cheapest$67	Average$200	FlexibilityNo cancel fee	On-time75%
Breeze Airways	Cheapest$78	Average$136	FlexibilityNo cancel fee	On-timeN/A
Delta	Cheapest$85	Average$197	FlexibilityNo cancel fee	On-timeN/A
Southwest	Cheapest$116	Average$303	FlexibilityNo cancel fee	On-time63%

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$37+ 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 5/26. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Ontario to San Francisco with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheapflights Tip: The best prices from Ontario to San Francisco are usually found in July or May, booked 87 days in advance, depart on a Friday or Saturday and return on a Monday

Cheap flight deals from Ontario to San Francisco

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Good round-trip deal

Good one-way deal

Find flight deals from Ontario to San Francisco

Cheapest flights from Ontario to San FranciscoExplore 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 April 29, 2025.

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 April 29, 2025.

Cheapflights Fare Finder

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

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 April.

The best insider tips for Ontario to San Francisco flights

Cheapflights partnered with top experts to bring you the best recommendations for your Ontario to San Francisco trip

Airlines

Frontier

United Airlines

Our travel experts

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.

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 April 25, 2025.

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

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 April 29, 2025.

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 March 30, 2025.

Rainfall in San Francisco by month

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

Temperature in San Francisco by month

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

Reviews of airlines servicing San Francisco

Read reviews from past customers who have flown Alaska Airlines, Southwest and Delta 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.

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?

How popular is this Ontario to San Francisco flight route?

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

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

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

What are the cheapest flights from Ontario to San Francisco?

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

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

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

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

Traveling to a place near Ontario?

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Alternative routes for Ontario to San Francisco

See prices for flight routes from nearby airports that may be better suited for you.

Top 7 airlines flying from Ontario to San Francisco

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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 April 29, 2025.