HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$39+ 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 6/21. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ONT
Apr 2 — Apr 91
Wed 4/2
Wed 4/9
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

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”
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 San Francisco to Ontario are usually found in May or July, booked 55 days in advance, depart on a Monday or Wednesday and return on a Friday

Cheap 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 March 28, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$72
(United Airlines)

One-way from

$39
(United Airlines)

Popular in

December

Cheapest in

May

Average price

$147

Good round-trip deal

$75 or less

Good one-way deal

$57 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. 26% potential increase in price ($43 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 8% potential price decrease ($11 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 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

Find 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 March 28, 2025.

This United Airlines deal was found by Cheapflights users on 3/28. 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.
Sat 5/310:54 amSFO - ONT
Nonstop1h 30mUnited Airlines
Sat 5/31:45 pmONT - SFO
Nonstop1h 28mUnited Airlines
Deal found 3/28$72
This Cheapflightsfares deal was found by Cheapflights users on 3/27. 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.
Thu 4/248:35 amSFO - ONT
Nonstop1h 28mFrontier
Fri 4/258:10 amONT - SFO
Nonstop1h 41mFrontier
Deal found 3/27$98
This Southwest deal was found by Cheapflights users on 3/26. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/105:40 amSFO - ONT
1 stop4h 10mSouthwest
Mon 4/147:35 pmONT - SFO
1 stop3h 50mSouthwest
Deal found 3/26$174
This American Airlines deal was found by Cheapflights users on 3/27. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/1012:06 pmSFO - ONT
1 stop6h 14mAmerican Airlines
Thu 4/107:25 pmONT - SFO
1 stop4h 33mAmerican Airlines
Deal found 3/27$193

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 March 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 5/3

10:54 am-12:24 pm

Nonstop1h 30m

Ontario

Sat 5/3

1:45 pm-3:13 pm

Nonstop1h 28m

$72

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 4/24

8:35 am-10:03 am

Nonstop1h 28m

Ontario

Fri 4/25

8:10 am-9:51 am

Nonstop1h 41m

$98

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 5/3

10:45 am-3:35 pm

1 stop4h 50m

Ontario

Tue 5/6

3:40 pm-10:40 pm

2 stops7h 00m

$156

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 4/10

12:06 pm-6:20 pm

1 stop6h 14m

Ontario

Thu 4/10

7:25 pm-11:58 pm

1 stop4h 33m

$193

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 6/21

9:18 pm-10:45 pm

Nonstop1h 27m

$39

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 7/24

10:11 pm-11:40 pm

Nonstop1h 29m

$47

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 4/24

5:10 am-11:00 am

1 stop5h 50m

$76

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 4/3

12:14 pm-6:33 pm

1 stop6h 19m

$100

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Tue 4/29

10:49 am-8:29 pm

2 stops9h 40m

$167

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 7/24

7:05 pm-11:59 pm

1 stop4h 54m

$421

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/28

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 March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*2 stars
Kiwi.comPrice Accuracy3 starsTrust Score*2 stars
Justfly.comPrice Accuracy3 starsTrust Score*3 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy1 starTrust Score*3 stars
CheapOairPrice Accuracy1 starTrust Score*3 stars
Trip.comPrice Accuracy1 starTrust Score*3 stars

*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 FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on San Francisco-Ontario flight deals on Cheapflights vs. FlightHub >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 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 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 March 21, 2025.

Booking 55 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, August is the cheapest month in which you can book a flight from San Francisco to Ontario (average of $246). Flying from San Francisco to Ontario in March is currently the most expensive (average of $326). 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 March 28, 2025.

Unlike in the evening, when flights are generally more expensive, you can save up to 38% on flights from San Francisco to Ontario by exploring options for tickets at noon.

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 March 23, 2025.

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

Rainfall in Ontario by month

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

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

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

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

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 March 28, 2025.
Get a feel of what it's like to fly with Southwest, Alaska Airlines and Hawaiian Airlines from San Francisco to Ontario by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,274 reviews

Food

7.1

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.7

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
Southwest
8.1
Very good
4,274 reviews
Southwest
8.1
Very good
4,274 reviews

Food

7.1

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.7

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
Alaska Airlines
8.0
Very good
9,797 reviews
Southwest
8.1
Very good
4,274 reviews

Food

7.1

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.7

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
Hawaiian Airlines
7.9
Good
2,335 reviews
Southwest
8.1
Very good
4,274 reviews

Food

7.1

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.7

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
United Airlines
7.4
Good
8,604 reviews
Southwest
8.1
Very good
4,274 reviews

Food

7.1

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.7

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,274 reviews

Food

7.1

Comfort

8.1

Overall

8.1

Entertainment

7.6

Crew

8.7

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.

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 3 daily flights to Ontario from 6 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, 109 users have taken a look at flights from San Francisco to Ontario.

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

    Flying on United Airlines is currently your cheapest option to Ontario, with prices starting at $72. Additional round-trip tickets that might be worth considering are offered by Frontier and Southwest, with the lowest prices starting at $98 and $156, respectively. You may be able to fly from San Francisco to Ontario for 41% 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 United Airlines, which is currently one of the cheapest options available, starting at $39. Frontier flights start at $47 while deals on Southwest start at $76 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 Copa Airlines (100%), United Airlines (91%) or Frontier (90%) 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 $180 for a flight from San Francisco to Ontario. The cheapest flight overall is $27 while the most popular route, (San Francisco - Ontario) is currently priced at $52.

  • 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, August is the cheapest month in which you can book a flight from San Francisco to Ontario (average of $246). Flying from San Francisco to Ontario in March is currently the most expensive (average of $326). 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for San Francisco to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
San Jose to Los Angeles flights
Burbank to Las Vegas flights
Los Angeles to Las Vegas flights
San Francisco to Los Angeles flights
Oakland to Los Angeles flights
Los Angeles to San Francisco flights
San Francisco to Las Vegas flights
Santa Ana to Las Vegas flights
Los Angeles to San Jose flights
Los Angeles to Oakland flights
San Francisco to Santa Ana flights
Oakland to Santa Ana flights
Oakland to Las Vegas flights
San Jose to Las Vegas flights
Ontario to San Francisco flights
Santa Ana to Oakland flights
Santa Ana to San Francisco flights
Oakland to San Diego flights
San Francisco to San Diego flights
San Jose to San Diego flights
San Francisco to Burbank flights
Ontario to Las Vegas flights
Los Angeles to Sacramento flights
San Jose to Santa Ana flights
Sacramento to Los Angeles flights
Burbank to San Francisco flights
Burbank to Oakland flights
San Diego to Las Vegas flights
San Diego to San Francisco flights
Sacramento to Las Vegas flights
Oakland to Burbank flights
San Francisco to Palm Springs flights
Sacramento to San Diego flights
Los Angeles to Reno flights
San Jose to Ontario flights
Las Vegas to Los Angeles flights
Santa Ana to San Jose flights
Ontario to Sacramento flights
San Diego to San Jose flights
San Diego to Oakland flights
Fresno to Las Vegas flights
Santa Ana to Sacramento flights
Burbank to Sacramento flights
Sacramento to Santa Ana flights
San Francisco to Long Beach flights
Las Vegas to Burbank flights
Santa Rosa to Las Vegas flights
Las Vegas to Santa Ana flights
San Diego to Sacramento flights

Top 6 airlines flying from San Francisco to Ontario

Discover the top 6 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 March 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$32Average$123FlexibilityNo cancel feeOn-time65%
FrontierCheapest$38Average$90FlexibilityNo cancel feeOn-time62%
DeltaCheapest$45Average$124FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$59Average$197FlexibilityNo cancel feeOn-time75%
Breeze AirwaysCheapest$78Average$110FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$93Average$243FlexibilityNo cancel feeOn-time69%
100% Free
Cheapflights is completely free to use, so you can start saving the moment you arrive.
Book with Flexibility
Our users can plan ahead with confidence and find flights with no change fees
Travel Smart
Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.