What is the cheapest airline that flies from Ontario to San Francisco?

United Airlines is the most popular carrier operating from Ontario to San Francisco

How many flights depart from Ontario to San Francisco on average per day?

The number of flights available between Ontario and San Francisco is 5 per day as of January 2026. The most frequent departure time is 10:00AM, with 61% of daily flights leaving at noon.

How many flights depart from Ontario to San Francisco on average per week?

As of January 2026, there are 41 flights per week flying from Ontario to San Francisco. The most common day of the week flights depart is Fri, with 22% of flights taking off on this day.

What airlines fly to San Francisco?

Frontier, United Airlines and Southwest are the top three most popular airlines that fly to San Francisco from Ontario according to our data. Frontier is the first choice among our users, with 28% of people opting to fly with this airline when traveling to San Francisco. Keep in mind that there are 11 different airlines that fly to San Francisco on a routine basis, so you have a few additional options to choose from.

When did momondo last update prices for flights from Ontario Airport to San Francisco Airport?

Prices for flights from Ontario Airport to San Francisco Airport are updated daily.

How many operators does momondo search for flights from Ontario Airport to San Francisco Airport?

There are 4 operators available for flights from Ontario Airport to San Francisco Airport as of January 2026.

How old do you have to be to fly from Ontario Airport to San Francisco Airport?

The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario Airport to San Francisco Airport.

What documentation or ID do you need to fly to San Francisco Airport?

The necessary travel and health documents for your San Francisco Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

$37 Cheap Flights from Ontario to San Francisco in 2026

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6:39 pm - 8:16 pm

ONT

SFO

1h 37mnonstop

8:06 pm - 9:33 pm

SFO

ONT

1h 27mnonstop

$115Frontier

Thu, Jan 15 - Mon, Jan 19

6:39 pm - 8:16 pm

ONT

SFO

1h 37mnonstop

8:06 pm - 9:33 pm

SFO

ONT

1h 27mnonstop

$126Frontier

Thu, Jan 15 - Mon, Jan 19

3:07 pm - 3:56 pm

ONT

SFO

24h 49m1 stop

2:08 pm - 10:09 am

SFO

ONT

20h 01m1 stop

$129Frontier

Wed, Jan 21 - Wed, Jan 28

11:04 am - 3:56 pm

ONT

SFO

4h 52m1 stop

10:48 am - 7:32 pm

SFO

ONT

8h 44m1 stop

$130Frontier

Thu, Jan 29 - Sun, Feb 1

11:04 am - 3:56 pm

ONT

SFO

4h 52m1 stop

11:33 am - 7:53 pm

SFO

ONT

8h 20m1 stop

$131Frontier

Thu, Jan 29 - Thu, Feb 5

11:04 am - 3:56 pm

ONT

SFO

4h 52m1 stop

7:00 am - 11:24 pm

SFO

ONT

16h 24m1 stop

$132Frontier

Thu, Jan 29 - Sat, Feb 7

3:07 pm - 3:56 pm

ONT

SFO

24h 49m1 stop

7:00 am - 3:07 pm

SFO

ONT

8h 07m1 stop

$133Frontier

Wed, Jan 21 - Tue, Jan 27

10:18 am - 5:00 pm

ONT

SFO

6h 42m1 stop

7:00 am - 11:24 pm

SFO

ONT

16h 24m1 stop

$134Frontier

Fri, Jan 30 - Sat, Feb 7

6:39 pm - 8:16 pm

ONT

SFO

1h 37mnonstop

8:06 pm - 9:33 pm

SFO

ONT

1h 27mnonstop

$135Frontier

Fri, Jan 16 - Mon, Jan 19

6:39 pm - 8:16 pm

ONT

SFO

1h 37mnonstop

8:06 pm - 9:33 pm

SFO

ONT

1h 27mnonstop

$136Frontier

Fri, Jan 16 - Mon, Jan 19

Frontier flights from Ontario to San Francisco

Our best Frontier deals on Ontario to San Francisco flight tickets

Frontier

Feb 18

ONT7:17 pmOntario

14h 36m

1 stop

SFO9:53 amSan Francisco

Feb 28

SFO8:58 amSan Francisco

23h 01m

1 stop

ONT7:59 amOntario

$129

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Frontier

Jan 29

ONT11:04 amOntario

4h 52m

1 stop

SFO3:56 pmSan Francisco

Feb 10

SFO6:55 amSan Francisco

14h 39m

1 stop

ONT9:34 pmOntario

$132

Find similar

Frontier

Jan 21

ONT3:07 pmOntario

24h 49m

1 stop

SFO3:56 pmSan Francisco

Jan 27

SFO7:00 amSan Francisco

8h 07m

1 stop

ONT3:07 pmOntario

$133

Find similar

Fly from

Fly to

Route

Depart

Return

Price

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 1/15

6:39 pm-8:16 pm

Nonstop1h 37m

San Francisco

Mon 1/19

8:06 pm-9:33 pm

Nonstop1h 27m

$115

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 1/15

6:39 pm-8:16 pm

Nonstop1h 37m

San Francisco

Mon 1/19

8:06 pm-9:33 pm

Nonstop1h 27m

$126

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 1/21

3:07 pm-3:56 pm

1 stop24h 49m

San Francisco

Wed 1/28

2:08 pm-10:09 am

1 stop20h 01m

$129

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 1/29

11:04 am-3:56 pm

1 stop4h 52m

San Francisco

Sun 2/1

10:48 am-7:32 pm

1 stop8h 44m

$130

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 1/29

11:04 am-3:56 pm

1 stop4h 52m

San Francisco

Thu 2/5

11:33 am-7:53 pm

1 stop8h 20m

$131

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 1/29

11:04 am-3:56 pm

1 stop4h 52m

San Francisco

Sat 2/7

7:00 am-11:24 pm

1 stop16h 24m

$132

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 1/21

3:07 pm-3:56 pm

1 stop24h 49m

San Francisco

Tue 1/27

7:00 am-3:07 pm

1 stop8h 07m

$133

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 1/30

10:18 am-5:00 pm

1 stop6h 42m

San Francisco

Sat 2/7

7:00 am-11:24 pm

1 stop16h 24m

$134

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 1/16

6:39 pm-8:16 pm

Nonstop1h 37m

San Francisco

Mon 1/19

8:06 pm-9:33 pm

Nonstop1h 27m

$135

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 1/16

6:39 pm-8:16 pm

Nonstop1h 37m

San Francisco

Mon 1/19

8:06 pm-9:33 pm

Nonstop1h 27m

$136

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How to get the cheapest flight ticket from Ontario to San Francisco

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

Prices

Airlines

Other information

What is the cheapest month to fly to San Francisco?

If you aren’t able to travel to San Francisco during the month of May, then flying in February is also cheap. Prices for this month can be found on momondo for an average of $99.

What is the cheapest day to depart on your flight to San Francisco?

The cheapest day to depart from Ontario to San Francisco is on a Friday when prices can be found for as low as $198. The most expensive day to fly to San Francisco is Monday, with ticket prices averaging around $349.

What is the cheapest time of day to depart on your flight to San Francisco?

Our data shows that the cheapest Ontario to San Francisco flights are usually those with departure times in the afternoon. Our users have found flights to San Francisco in the afternoon for as low as $178. Flights in the evening are often more expensive with an average ticket price of $476.

What is the cheapest Ontario to San Francisco flight route?

Fly from Ontario to San Francisco for the best Ontario - San Francisco flight prices

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

You are more likely to see cheaper flights to San Francisco from Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to San Francisco for around $139 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to San Francisco from Ontario for as low as $105 on momondo.

What cabin class options are available on Ontario to San Francisco flights?

There are 4 cabin classes available to choose from on Ontario to San Francisco flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have Ontario to San Francisco flight prices changed over time?

As of January 2026, prices for Ontario to San Francisco flights are approximately 51% cheaper when compared to flights at the same time last year.

When to book flights from Ontario to San Francisco

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to San Francisco according to our flight data. Find out which month and days have the cheapest flights.

Estimated round-trip price

Cheap Ontario to San Francisco (ONT to SFO) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to San Francisco

Best Price Found	$113
Fastest flight time	1h 29m
Direct flights	Every day
Airports in San Francisco	1 airport

The best one-way flight to San Francisco from Ontario in the past 72 hours is $113. The best round-trip flight deal from Ontario to San Francisco found on momondo in the last 72 hours is $215.

The fastest flight from Ontario to San Francisco takes 1h 29m

Direct flights go from Ontario to San Francisco every day.

There is 1 airport in San Francisco. From Ontario there are direct flights to San Francisco (SFO).

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How far is Ontario to San Francisco by plane?
The straight-line distance from Ontario to San Francisco is 370.2 mi. In terms of flight time, this usually takes a little over 1h 29m.
When did momondo last update prices for flights from Ontario Airport to San Francisco Airport?
Prices for flights from Ontario Airport to San Francisco Airport are updated daily.
How many operators does momondo search for flights from Ontario Airport to San Francisco Airport?
There are 4 operators available for flights from Ontario Airport to San Francisco Airport as of January 2026.
How old do you have to be to fly from Ontario Airport to San Francisco Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario Airport to San Francisco Airport.
What documentation or ID do you need to fly to San Francisco Airport?
The necessary travel and health documents for your San Francisco Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from Ontario to San Francisco?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from Ontario to San Francisco is Boeing 737 MAX 8 (15.92% of total bookings). The next most popular plane models are Airbus A320neo (14.35%), Airbus A320-100/200 (13.77%), and Boeing 737-800 (8.81%).
What is the most popular airline from Ontario to San Francisco?
momondo data reveals that the most frequently booked airline on the route from Ontario to San Francisco is United Airlines, representing 57% of all bookings. The subsequent popular airlines are Frontier at 42%, Alaska Airlines at 1%, and Southwest at 0%.

Best airlines flying from Ontario to San Francisco

Compare and see reviews for airlines that fly from Ontario to San Francisco with momondo

Airline	Rating	Free Cancellation	Price
Frontier	PriceFrom $35	Free Cancellation	Rating 5.7 3,066 reviews	Search Frontier flights
United Airlines	PriceFrom $58	Free Cancellation	Rating 7.4 9,132 reviews	Search United Airlines flights
Alaska Airlines	PriceFrom $67	Free Cancellation	Rating 8.0 11,597 reviews	Search Alaska Airlines flights
Southwest	PriceFrom $116	Free Cancellation	Rating 8.0 4,252 reviews	Search Southwest flights

United Airlines Flights From Ontario to San Francisco
United Airlines flight deals from Ontario to San Francisco start from $58 round-trip. Over the 13 United Airlines flights for this route in a normal week, average airfare is usually $185 round-trip - but some users have found much cheaper deals with momondo.
Frontier Flights From Ontario to San Francisco
Across 3,066 Frontier reviews on momondo, the average score is 5.7/10. Frontier flies from Ontario to San Francisco about 3 times each week, with ticket deals ranging from $35 to $105. Price data is based on momondo searches in the last 72 hours.

Santa Cruz

Carmel-by-the-Sea

Modesto

Sonoma

Bodega Bay

Roseville

Hayward

Calistoga

Big Sur

Santa Clara

Berkeley

Walnut Creek

Fremont

Daly City

Half Moon Bay

Vallejo

Livermore

Salinas

Sunnyvale

Turlock

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to San Francisco?

It is quick and easy to find Ontario to San Francisco flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to San Francisco that suits you.

Can I find flights from Ontario to San Francisco with flexible booking policies on momondo?

Flights from Ontario to San Francisco with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from Ontario to San Francisco?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Ontario to San Francisco.

I’m not ready to book a flight from Ontario to San Francisco right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to San Francisco from Ontario. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

An easier way to manage your San Francisco trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

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Cheap flights from Ontario to San Francisco from $67

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to San Francisco departing on 1/21. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

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Frontier flights from Ontario to San Francisco

Our best Frontier deals on Ontario to San Francisco flight tickets

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

See travel insights to San Francisco from

How to get the cheapest flight ticket from Ontario to San Francisco

What is the cheapest month to fly to San Francisco?

If you aren’t able to travel to San Francisco during the month of May, then flying in February is also cheap. Prices for this month can be found on momondo for an average of $99.

What is the cheapest day to depart on your flight to San Francisco?

The cheapest day to depart from Ontario to San Francisco is on a Friday when prices can be found for as low as $198. The most expensive day to fly to San Francisco is Monday, with ticket prices averaging around $349.

What is the cheapest time of day to depart on your flight to San Francisco?

Our data shows that the cheapest Ontario to San Francisco flights are usually those with departure times in the afternoon. Our users have found flights to San Francisco in the afternoon for as low as $178. Flights in the evening are often more expensive with an average ticket price of $476.

What is the cheapest Ontario to San Francisco flight route?

Fly from Ontario to San Francisco for the best Ontario - San Francisco flight prices

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

What cabin class options are available on Ontario to San Francisco flights?

There are 4 cabin classes available to choose from on Ontario to San Francisco flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have Ontario to San Francisco flight prices changed over time?

As of January 2026, prices for Ontario to San Francisco flights are approximately 51% cheaper when compared to flights at the same time last year.

What is the cheapest airline that flies from Ontario to San Francisco?

United Airlines is the most popular carrier operating from Ontario to San Francisco

What airlines fly to San Francisco?

How many flights depart from Ontario to San Francisco on average per day?

The number of flights available between Ontario and San Francisco is 5 per day as of January 2026. The most frequent departure time is 10:00AM, with 61% of daily flights leaving at noon.

How many flights depart from Ontario to San Francisco on average per week?

As of January 2026, there are 41 flights per week flying from Ontario to San Francisco. The most common day of the week flights depart is Fri, with 22% of flights taking off on this day.

When to book flights from Ontario to San Francisco

Cheap Ontario to San Francisco (ONT to SFO) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to San Francisco

Best Price Found

Fastest flight time

Direct flights

Airports in San Francisco

How far is Ontario to San Francisco by plane?

When did momondo last update prices for flights from Ontario Airport to San Francisco Airport?

How many operators does momondo search for flights from Ontario Airport to San Francisco Airport?

How old do you have to be to fly from Ontario Airport to San Francisco Airport?

What documentation or ID do you need to fly to San Francisco Airport?

What is the most popular plane model from Ontario to San Francisco?

What is the most popular airline from Ontario to San Francisco?

Best airlines flying from Ontario to San Francisco

Compare and see reviews for airlines that fly from Ontario to San Francisco with momondo

United Airlines Flights From Ontario to San Francisco

Frontier Flights From Ontario to San Francisco

Traveling to a place near San Francisco?

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to San Francisco?

Can I find flights from Ontario to San Francisco with flexible booking policies on momondo?

How can momondo help me find flights from Ontario to San Francisco?

I’m not ready to book a flight from Ontario to San Francisco right now. Can momondo alert me if prices change?

An easier way to manage your San Francisco trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to the United States

Airports servicing California