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$64+ Cheap flights from San Francisco to Ontario (SFO - ONT)

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 1/21. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ONT
Jan 27 — Feb 31
Tue 1/27
Tue 2/3
1 adult, Economy
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Find cheap flights from San Francisco to Ontario 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”

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Cheapflights Tip: The best prices from San Francisco to Ontario are usually found in February or May, booked 69 days in advance, depart on a Monday or Thursday and return on a Friday

Cheap flight deals from San Francisco to Ontario

Cheapest flights from San Francisco to Ontario
Explore the most affordable flight options available from San Francisco to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 28, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 12/26. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/2910:44 pmSFO - ONT
Nonstop1h 28mFrontier
Mon 1/510:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/26$274
This Cheapflightsfares deal was found by Cheapflights users on 12/26. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/2910:44 pmSFO - ONT
Nonstop1h 28mFrontier
Fri 1/210:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/26$284
This Booking.com deal was found by Cheapflights users on 12/26. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/2910:44 pmSFO - ONT
Nonstop1h 28mFrontier
Sun 1/410:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/26$286
This Booking.com deal was found by Cheapflights users on 12/26. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/2910:44 pmSFO - ONT
Nonstop1h 28mFrontier
Fri 1/96:00 amONT - SFO
1 stop18h 24mFrontier
Deal found 12/26$295
This Cheapflightsfares deal was found by Cheapflights users on 12/26. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/2910:44 pmSFO - ONT
Nonstop1h 28mFrontier
Tue 1/67:52 amONT - SFO
1 stop4h 02mFrontier
Deal found 12/26$320
This Cheapflightsfares deal was found by Cheapflights users on 12/27. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2810:31 pmSFO - ONT
Nonstop1h 28mFrontier
Mon 1/510:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/27$324

Find flight deals from San Francisco to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from San Francisco (SFO) to Ontario (ONT). 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 December 28, 2025.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$118
(CheapOair)

One-way from

$64
(Frontier)

Popular in

December

Cheapest in

February

Average price

$226

Good round-trip deal

$166 or less

Good one-way deal

$84 or less
Provider with most accurate pricing for San Francisco-Ontario flight deals.
Search Deals
Provider most trusted by Cheapflights users for San Francisco-Ontario flights.
Search Deals
From San Francisco to Ontario
Search Deals
One-way flight from San Francisco to Ontario
Search Deals
Highest demand for flights based on searches. 12% potential increase in price ($24 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($6 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals
Price to beat on a round-trip flight from San Francisco to Ontario.
Search Deals
Price to beat on a one-way flight from San Francisco to Ontario.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from San Francisco to Ontario 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 December 28, 2025.
Use the filters below to find and compare flights from San Francisco to Ontario that are best for you.

Fly from

San Francisco

Fly to

Ontario

Route

Depart

Return

Price

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 1/24

2:35 pm-10:51 pm

1 stop8h 16m

Ontario

Mon 1/26

7:30 am-11:30 pm

1 stop16h 00m

$225

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 3/4

4:13 pm-5:41 pm

Nonstop1h 28m

Ontario

Wed 3/11

6:00 am-7:33 am

Nonstop1h 33m

$229

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 1/21

2:35 pm-11:58 pm

2 stops9h 23m

Ontario

Tue 1/27

7:30 am-1:43 pm

1 stop6h 13m

$230

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 1/22

4:20 pm-5:43 pm

Nonstop1h 23m

Ontario

Wed 1/28

1:53 pm-3:25 pm

Nonstop1h 32m

$252

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 1/31

9:30 pm-10:53 pm

Nonstop1h 23m

Ontario

Tue 2/3

1:53 pm-3:25 pm

Nonstop1h 32m

$252

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 1/28

9:30 pm-10:53 pm

Nonstop1h 23m

Ontario

Sat 1/31

6:00 am-7:32 am

Nonstop1h 32m

$252

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Tue 1/27

2:30 pm-8:36 pm

1 stop6h 06m

Ontario

Tue 2/3

11:53 am-5:59 pm

1 stop6h 06m

$264

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 1/28

9:00 am-5:03 pm

2 stops8h 03m

Ontario

Mon 2/9

6:00 am-11:03 pm

1 stop17h 03m

$269

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 2/4

9:30 pm-10:53 pm

Nonstop1h 23m

Ontario

Sun 2/8

6:00 am-7:32 am

Nonstop1h 32m

$274

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sun 2/15

9:30 pm-10:57 pm

Nonstop1h 27m

Ontario

Wed 2/18

6:09 am-7:42 am

Nonstop1h 33m

$274

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/28

Showing 1-10 of 23 results
1
2
3

Compare providers for flights from San Francisco to Ontario

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 San Francisco to Ontario in December.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*2 stars
JustAirTicketPrice Accuracy-Trust Score*1 star
PricelinePrice Accuracy1 starTrust Score*3 stars
MytripPrice 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 San Francisco-Ontario flights, users find the pricing of Mytrip to be most consistent on Cheapflights vs. Mytrip Users can find the same prices on San Francisco-Ontario flight deals on Cheapflights vs. Mytrip >95% of the time. Price accuracy is based on data collected from San Francisco-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on San Francisco-Ontario 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 San Francisco-Ontario 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 San Francisco to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from San Francisco 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 San Francisco to Ontario

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

Use this chart to determine the optimal time to book a round-trip flight from San Francisco to Ontario. Price data was last updated on December 26, 2025.

Booking 69 days in advance of your planned departure date is, on average, the best time to get cheap flights from San Francisco to Ontario. 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 San Francisco to Ontario?

Currently, February is the cheapest month in which you can book a flight from San Francisco to Ontario (average of $19). Flying from San Francisco to Ontario in July is currently the most expensive (average of $57). 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 SFO to ONT?

Find hourly flight availability from San Francisco to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 28, 2025.

Unlike at noon, when flights are generally more expensive, you can save up to 43% on flights from San Francisco to Ontario by exploring options for tickets in the evening.

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

Use this chart to determine the cheapest time to fly round-trip from San Francisco to Ontario. Price data was last updated on December 20, 2025.

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

The best insider tips for San Francisco to Ontario flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your San Francisco to Ontario trip
Airports
SFO

Save time by using the SFO2Go program to order meals for pickup during busy times.

Read more about SFOBy Harriet Baskas
ONT

Consider renting a car at ONT for convenient travel in the L.A. area.

Read more about ONTBy Bill Fink
Our travel experts
Bill Fink

Bill Fink

Expert on ONT

Bill Fink

Bill Fink

Bill is an award-winning travel writer with extensive credits covering airlines and the aviation industry for publications including AARP, AFAR, The Points Guy and Yahoo. Based in Portland, Oregon, Bill has traveled to more than 75 countries - and been late for his flight in most of them. He once achieved top-level frequent flier status for all of American, Delta and United Airlines during a single year.

Read more
Harriet Baskas

Harriet Baskas

Expert on SFO

Harriet Baskas

Harriet Baskas

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Read more

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated December 28, 2025.
Peruse reviews from past customers who have flown with Alaska Airlines, Delta, and United Airlines from San Francisco to Ontario to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
11,552 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Alaska Airlines
8.0
Very good
11,552 reviews
Alaska Airlines
8.0
Very good
11,552 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Delta
7.9
Good
8,017 reviews
Alaska Airlines
8.0
Very good
11,552 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
United Airlines
7.4
Good
9,114 reviews
Alaska Airlines
8.0
Very good
11,552 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
American Airlines
7.2
Good
11,070 reviews
Alaska Airlines
8.0
Very good
11,552 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Frontier
5.8
Fair
3,064 reviews
Alaska Airlines
8.0
Very good
11,552 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.

Related info for your journey

Find useful and relevant information for your journey from San Francisco to Ontario. 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 San Francisco to Ontario?

    Ontario is the airport most travelers will use when flying to Ontario from San Francisco. Booking flights from San Francisco (SFO) to Ontario (ONT) should be relatively easy as there are 6 daily flights to Ontario from 5 different airlines. 1h 23m is how long a flight from San Francisco to Ontario will take if you book a nonstop flight.

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

    Within the past month, 54 users have taken a look at flights from San Francisco to Ontario.

  • How long is the flight from San Francisco to Ontario?

    A quick flight from San Francisco to Ontario can take about 1h 28m. Delta provides one of the quickest options available for as low as $229. San Francisco and Ontario are separated by a distance of 363 mi. This flight may include one or multiple stops.

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

    Flying on Frontier is currently your cheapest option to Ontario, with prices starting at $32. Additional round-trip tickets that might be worth considering are offered by United Airlines and Alaska Airlines, with the lowest prices starting at $58 and $59, respectively. You may be able to fly from San Francisco to Ontario for 80% less than the average price by searching for these airlines.

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

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $25. United Airlines flights start at $28 while deals on Alaska Airlines start at $58 one-way.

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

    No one likes to see their flight delayed. When booking a flight from San Francisco to Ontario consider choosing SkyWest Airlines (100%), Emirates (86%) or United Airlines (86%) as they are the most reliable in getting you off to your destination on time.

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

    On average you can expect to pay $176 for a flight from San Francisco to Ontario. The cheapest flight overall is $44 while the most popular route, (San Francisco - Ontario) is currently priced at $139.

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

    Yes. In addition to deals on San Francisco to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

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

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from San Francisco to Ontario.

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

    Yes. Cheapflights offers flight deals from San Francisco to Ontario 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 San Francisco to Ontario?

    Currently, February is the cheapest month in which you can book a flight from San Francisco to Ontario (average of $19). Flying from San Francisco to Ontario in July is currently the most expensive (average of $57). 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

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Alternative routes for San Francisco to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Top 5 airlines flying from San Francisco to Ontario

Discover the top 5 airlines that operate flights from San Francisco to Ontario. 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 December 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$38Average$121FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$58Average$212FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$59Average$169FlexibilityNo cancel feeOn-time75%
DeltaCheapest$108Average$201FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$186Average$206FlexibilityNo cancel feeOn-time71%

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