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Cheap flights from Ontario to San Francisco from $39

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 10/6. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from Ontario to San Francisco

Cheap round-trip flights

Frontier Logo
9:46 pm - 11:15 pmONT-SFO
1h 29mnonstop
Frontier Logo
10:11 pm - 11:38 pmSFO-ONT
1h 27mnonstop
$77Frontier
Find Deal
Mon, Sep 22 - Thu, Sep 25
Frontier Logo
9:46 pm - 11:15 pmONT-SFO
1h 29mnonstop
Frontier Logo
10:11 pm - 11:38 pmSFO-ONT
1h 27mnonstop
$78Frontier
Find Deal
Thu, Sep 4 - Mon, Sep 8
Frontier Logo
9:46 pm - 11:15 pmONT-SFO
1h 29mnonstop
Frontier Logo
10:11 pm - 11:38 pmSFO-ONT
1h 27mnonstop
$79Frontier
Find Deal
Thu, Sep 11 - Mon, Sep 15
Frontier Logo
9:41 pm - 11:14 pmONT-SFO
1h 33mnonstop
Frontier Logo
10:11 pm - 11:40 pmSFO-ONT
1h 29mnonstop
$85Frontier
Find Deal
Mon, Aug 25 - Thu, Aug 28
Frontier Logo
9:46 pm - 11:15 pmONT-SFO
1h 29mnonstop
Frontier Logo
10:11 pm - 11:38 pmSFO-ONT
1h 27mnonstop
$93Frontier
Find Deal
Thu, Sep 18 - Sun, Sep 21
Frontier Logo
9:41 pm - 11:14 pmONT-SFO
1h 33mnonstop
Frontier Logo
10:11 pm - 11:40 pmSFO-ONT
1h 29mnonstop
$94Frontier
Find Deal
Thu, Aug 28 - Sun, Aug 31
Frontier Logo
9:46 pm - 11:15 pmONT-SFO
1h 29mnonstop
Frontier Logo
10:11 pm - 11:38 pmSFO-ONT
1h 27mnonstop
$95Frontier
Find Deal
Thu, Sep 4 - Sun, Sep 7
Frontier Logo
9:46 pm - 11:15 pmONT-SFO
1h 29mnonstop
Frontier Logo
10:11 pm - 11:38 pmSFO-ONT
1h 27mnonstop
$96Frontier
Find Deal
Thu, Sep 4 - Sun, Sep 7
Frontier Logo
9:46 pm - 11:15 pmONT-SFO
1h 29mnonstop
Frontier Logo
10:11 pm - 11:38 pmSFO-ONT
1h 27mnonstop
$97Frontier
Find Deal
Thu, Sep 4 - Sun, Sep 7
Frontier Logo
9:46 pm - 11:15 pmONT-SFO
1h 29mnonstop
Frontier Logo
10:11 pm - 11:38 pmSFO-ONT
1h 27mnonstop
$98Frontier
Find Deal
Thu, Sep 4 - Sun, Sep 7

Frontier flights from Ontario to San Francisco

Our best Frontier deals on Ontario to San Francisco flight tickets
Frontier
Sep 22
ONT9:46 pmOntario
1h 29m
SFO11:15 pmSan Francisco
Sep 25
SFO10:11 pmSan Francisco
1h 27m
ONT11:38 pmOntario
$77
Find similar
Frontier
Sep 4
ONT9:46 pmOntario
1h 29m
SFO11:15 pmSan Francisco
Sep 8
SFO10:11 pmSan Francisco
1h 27m
ONT11:38 pmOntario
$78
Find similar
Frontier
Sep 11
ONT9:46 pmOntario
1h 29m
SFO11:15 pmSan Francisco
Sep 15
SFO10:11 pmSan Francisco
1h 27m
ONT11:38 pmOntario
$79
Find similar

United Airlines flights from Ontario to San Francisco

Our best United Airlines deals on Ontario to San Francisco flight tickets
United Airlines
Aug 6
ONT6:10 amOntario
1h 27m
SFO7:37 amSan Francisco
Aug 12
SFO10:45 amSan Francisco
1h 29m
ONT12:14 pmOntario
$157
Find similar
United Airlines
Aug 12
ONT6:10 amOntario
1h 27m
SFO7:37 amSan Francisco
Aug 12
SFO10:45 amSan Francisco
1h 29m
ONT12:14 pmOntario
$182
Find similar

momondo 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, momondo users made 832,500 searches. Data last updated August 5, 2025.
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

Mon 9/22

9:46 pm-11:15 pm

Nonstop1h 29m

San Francisco

Thu 9/25

10:11 pm-11:38 pm

Nonstop1h 27m

$77

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/4

9:46 pm-11:15 pm

Nonstop1h 29m

San Francisco

Mon 9/8

10:11 pm-11:38 pm

Nonstop1h 27m

$78

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/11

9:46 pm-11:15 pm

Nonstop1h 29m

San Francisco

Mon 9/15

10:11 pm-11:38 pm

Nonstop1h 27m

$79

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Mon 8/25

9:41 pm-11:14 pm

Nonstop1h 33m

San Francisco

Thu 8/28

10:11 pm-11:40 pm

Nonstop1h 29m

$85

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/18

9:46 pm-11:15 pm

Nonstop1h 29m

San Francisco

Sun 9/21

10:11 pm-11:38 pm

Nonstop1h 27m

$93

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 8/28

9:41 pm-11:14 pm

Nonstop1h 33m

San Francisco

Sun 8/31

10:11 pm-11:40 pm

Nonstop1h 29m

$94

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/4

9:46 pm-11:15 pm

Nonstop1h 29m

San Francisco

Sun 9/7

10:11 pm-11:38 pm

Nonstop1h 27m

$95

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/4

9:46 pm-11:15 pm

Nonstop1h 29m

San Francisco

Sun 9/7

10:11 pm-11:38 pm

Nonstop1h 27m

$96

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/4

9:46 pm-11:15 pm

Nonstop1h 29m

San Francisco

Sun 9/7

10:11 pm-11:38 pm

Nonstop1h 27m

$97

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 9/4

9:46 pm-11:15 pm

Nonstop1h 29m

San Francisco

Sun 9/7

10:11 pm-11:38 pm

Nonstop1h 27m

$98

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to San Francisco from

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

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 September is also cheap. Prices for this month can be found on momondo for an average of $98.

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 $179. The most expensive day to fly to San Francisco is Sunday, with ticket prices averaging around $298.

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 $156. Flights in the evening are often more expensive with an average ticket price of $580.

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 $117 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 $94 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 August 2025, prices for Ontario to San Francisco flights are approximately 5% 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

$39

Fastest flight time

1h 19m

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 $39. The best round-trip flight deal from Ontario to San Francisco found on momondo in the last 72 hours is $77.
The fastest flight from Ontario to San Francisco takes 1h 19m
Direct flights go from Ontario to San Francisco every day.
There is 1 airport near San Francisco: San Francisco (SFO)
Search flight deals

  • 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?

  • 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?

  • 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
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $35Free CancellationRating
5.8
3,232 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $37Free CancellationRating
6.3
8,052 reviews
Search Spirit Airlines flights
United AirlinesPriceFrom $58Free CancellationRating
7.4
8,910 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $67Free CancellationRating
8.0
10,000 reviews
Search Alaska Airlines flights
DeltaPriceFrom $85Free CancellationRating
8.0
7,990 reviews
Search Delta flights
SouthwestPriceFrom $116Free CancellationRating
8.0
4,247 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 15 United Airlines flights for this route in a normal week, average airfare is usually $199 round-trip - but some users have found much cheaper deals with momondo.

Traveling to a place near San Francisco?

Book flights to San Francisco if you plan to visit one of these locations
Santa Cruz
Carmel-by-the-Sea
Modesto
Calistoga
Hayward
Sonoma
Bodega Bay
Roseville
Santa Clara
Big Sur
Daly City
Berkeley
Fremont
Walnut Creek
Half Moon Bay
South San Francisco
Vallejo
Redwood City
Sunnyvale
Pacific Grove

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.
Start using Trips
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