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$39+ Cheap flights from Ontario (ONT) to San Francisco Bay Area

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 3/20. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
Mar 15 — Mar 221
Sat 3/15
Sat 3/22
1 adult, Economy
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Cheap flight deals from Ontario to San Francisco Bay Area

Keep the following information in mind while searching for Ontario to San Francisco Bay Area flight deals. Data was last updated March 10, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$57
(United Airlines)

One-way from

$39
(CheapOair)

Popular in

March

Cheapest in

October

Average price

$153
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From Ontario to San Francisco Bay Area
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One-way flight from Ontario to San Francisco Bay Area
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Highest demand for flights based on searches. 5% potential increase in price ($7 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($2 potential savings vs. average RT price).
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Average for round-trip flights in March 2025
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Find flight deals from Ontario to San Francisco Bay Area

Cheapest flights from Ontario to San Francisco Bay Area
Explore the most affordable flight options available from Ontario to San Francisco Bay Area. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 10, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 3/9. 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 3/278:26 amONT - SFO
Nonstop1h 36mFrontier
Thu 4/38:35 amSFO - ONT
Nonstop1h 28mFrontier
Deal found 3/9$63
This United Airlines deal was found by Cheapflights users on 3/9. 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.
Mon 5/56:00 amONT - SFO
Nonstop1h 27mUnited Airlines
Mon 5/510:54 amSFO - ONT
Nonstop1h 30mUnited Airlines
Deal found 3/9$112
This Southwest deal was found by Cheapflights users on 3/10. 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.
Mon 4/78:50 amONT - SJC
1 stop5h 05mSouthwest
Wed 4/94:30 pmSJC - ONT
1 stop3h 40mSouthwest
Deal found 3/10$117
This CheapOair deal was found by Cheapflights users on 3/9. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/82:43 pmONT - SJC
1 stop3h 55mFrontier
Tue 4/157:28 pmSJC - ONT
1 stop24h 51mFrontier
Deal found 3/9$150
This Southwest deal was found by Cheapflights users on 3/10. 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.
Tue 4/110:40 amONT - OAK
Nonstop1h 25mSouthwest
Tue 4/15:35 pmOAK - ONT
Nonstop1h 25mSouthwest
Deal found 3/10$191
This Southwest deal was found by Cheapflights users on 3/10. 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.
Mon 5/123:55 pmONT - SFO
1 stop4h 20mSouthwest
Tue 5/205:15 amSFO - ONT
2 stops7h 15mSouthwest
Deal found 3/10$216
This American Airlines deal was found by Cheapflights users on 3/9. 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.
Fri 4/1810:00 amONT - STS
1 stop5h 46mAmerican Airlines
Mon 4/214:17 pmSTS - ONT
1 stop5h 41mAmerican Airlines
Deal found 3/9$257
This Alaska Airlines deal was found by Cheapflights users on 3/10. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/155:44 pmONT - OAK
1 stop14h 59mAlaska Airlines
Wed 4/1610:50 amOAK - ONT
1 stop13h 09mAlaska Airlines
Deal found 3/10$263
This Alaska Airlines deal was found by Cheapflights users on 3/9. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/96:55 amONT - SJC
1 stop9h 22mAlaska Airlines
Tue 4/227:00 amSJC - ONT
1 stop16h 58mAlaska Airlines
Deal found 3/9$263
This American Airlines deal was found by Cheapflights users on 3/9. 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.
Sat 4/194:35 pmONT - SJC
1 stop6h 12mAmerican Airlines
Mon 4/217:20 pmSJC - ONT
1 stop16h 39mAmerican Airlines
Deal found 3/9$321
This Delta deal was found by Cheapflights users on 3/9. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/55:30 pmONT - SJC
1 stop17h 25mDelta
Wed 5/711:40 amSJC - ONT
1 stop6h 39mDelta
Deal found 3/9$333
This Delta deal was found by Cheapflights users on 3/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/117:05 pmONT - OAK
2 stops28h 42mDelta
Wed 5/146:00 amOAK - ONT
2 stops16h 35mDelta
Deal found 3/10$349

Find flights from Ontario to San Francisco Bay Area within your budget

Customize your flight search to find flights from Ontario to San Francisco Bay Area 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 10, 2025.

Fly from

Ontario

Fly to

San Francisco Bay Area

Route

Depart

Return

Price

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sun 4/6

6:00 am-7:28 am

Nonstop1h 28m

San Francisco

Tue 4/8

1:20 pm-2:50 pm

Nonstop1h 30m

$57

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 5/2

8:24 am-10:02 am

Nonstop1h 38m

San Francisco

Sun 5/4

8:34 am-10:02 am

Nonstop1h 28m

$58

OntarioSan Jose

ONT - SJC

ONTSJC

Ontario

Wed 4/9

7:00 pm-8:10 pm

Nonstop1h 10m

San Jose

Wed 4/16

6:35 am-10:35 am

1 stop4h 00m

$107

OntarioSan Jose

ONT - SJC

ONTSJC

Ontario

Thu 4/3

3:02 pm-8:09 pm

1 stop5h 07m

San Jose

Sat 4/5

12:03 pm-9:12 pm

1 stop9h 09m

$145

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 4/29

3:40 pm-10:40 pm

2 stops7h 00m

San Francisco

Thu 5/1

5:40 am-9:50 am

1 stop4h 10m

$156

OntarioOakland

ONT - OAK

ONTOAK

Ontario

Tue 4/1

10:40 am-12:05 pm

Nonstop1h 25m

Oakland

Tue 4/1

5:35 pm-7:00 pm

Nonstop1h 25m

$191

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 4/17

7:00 am-10:14 pm

2 stops15h 14m

San Francisco

Sun 4/20

8:35 am-10:03 am

Nonstop1h 28m

$221

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 5/10

10:00 am-4:03 pm

1 stop6h 03m

San Francisco

Sun 5/11

12:04 pm-6:23 pm

1 stop6h 19m

$229

OntarioSanta Rosa

ONT - STS

ONTSTS

Ontario

Fri 4/18

10:00 am-3:46 pm

1 stop5h 46m

Santa Rosa Sonoma County

Mon 4/21

4:17 pm-9:58 pm

1 stop5h 41m

$257

OntarioOakland

ONT - OAK

ONTOAK

Ontario

Tue 4/15

5:44 pm-8:43 am

1 stop14h 59m

Oakland

Wed 4/16

10:50 am-11:59 pm

1 stop13h 09m

$263

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/10

Showing 1-10 of 42 results
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Best time to book a flight from Ontario to San Francisco Bay Area

Have a flexible travel schedule? Discover the best time to fly to San Francisco Bay Area 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.

Travel insights for flights from Ontario to San Francisco Bay Area

Get recent, data-driven insights about flights from Ontario to San Francisco Bay Area including ideal travel times, pricing trends, and more.

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

Currently, January is the cheapest month in which you can book a flight from Ontario to San Francisco Bay Area (average of $276). Flying from Ontario to San Francisco Bay Area in June is currently the most expensive (average of $400). 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 XIH?

Find hourly flight availability from Ontario to San Francisco Bay Area. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 10, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Ontario to San Francisco Bay Area as you normally would.

Weekly flight availability from Ontario to San Francisco Bay Area

Explore weekly flight availability from Ontario to San Francisco Bay Area. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated March 10, 2025.

The most flights from ONT to zzXIH are scheduled on a Sunday (11 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (6 on average).

Rainfall in San Francisco Bay Area by month

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

In terms of precipitation, rainfall in San Francisco Bay Area 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 Bay Area when rainfall is around 0.0 in.

Temperature in San Francisco Bay Area by month

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

If weather is an important factor for your trip to San Francisco Bay Area, 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 Bay Area

Get insights into the airlines that provide service to San Francisco Bay Area. 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 San Francisco Bay Area. Reviews last updated March 10, 2025.
Read reviews from past customers who have flown Southwest, Alaska Airlines and Delta from Ontario to San Francisco Bay Area. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,300 reviews

Boarding

8.2

Comfort

8.1

Entertainment

7.6

Overall

8.1

Food

7.1

Crew

8.7

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
4,300 reviews
Southwest
8.1
Very good
4,300 reviews

Boarding

8.2

Comfort

8.1

Entertainment

7.6

Overall

8.1

Food

7.1

Crew

8.7

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
9,731 reviews
Southwest
8.1
Very good
4,300 reviews

Boarding

8.2

Comfort

8.1

Entertainment

7.6

Overall

8.1

Food

7.1

Crew

8.7

Reviews

1 / 20

10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

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

Delta
8.0
Very good
7,973 reviews
Southwest
8.1
Very good
4,300 reviews

Boarding

8.2

Comfort

8.1

Entertainment

7.6

Overall

8.1

Food

7.1

Crew

8.7

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
2,320 reviews
Southwest
8.1
Very good
4,300 reviews

Boarding

8.2

Comfort

8.1

Entertainment

7.6

Overall

8.1

Food

7.1

Crew

8.7

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
8,631 reviews
Southwest
8.1
Very good
4,300 reviews

Boarding

8.2

Comfort

8.1

Entertainment

7.6

Overall

8.1

Food

7.1

Crew

8.7

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 Ontario to San Francisco Bay Area. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Ontario to San Francisco Bay Area?

    Ontario (ONT), located 3.1 mi from the city center, is the airport you fly out of when you book flights from Ontario to San Francisco Bay Area.

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

    Within the past month, 193 users have taken a look at flights from Ontario to San Francisco Bay Area.

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

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $39. Southwest flights start at $49 while deals on United Airlines start at $59 one-way.

  • What are the most popular routes from Ontario to San Francisco Bay Area?

    The most popular route from Ontario to San Francisco Bay Area is Ontario - San Francisco. You may also consider Ontario - San Jose or Ontario - Oakland.

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

    Consider Frontier (93%), SkyWest Airlines (89%) or United Airlines (88%) when booking your flight. These represent the most reliable airlines when flying from Ontario to San Francisco Bay Area.

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

    The cheapest flight price from Ontario to San Francisco Bay Area is $19. On average you can expect to pay $1,694. The most popular route, (Ontario - San Francisco), can usually be booked for $57.

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

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

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

    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 Bay Area.

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

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

    Currently, January is the cheapest month in which you can book a flight from Ontario to San Francisco Bay Area (average of $276). Flying from Ontario to San Francisco Bay Area in June is currently the most expensive (average of $400). 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.

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Alternative routes for Ontario to San Francisco Bay Area

See prices for flight routes from nearby airports that may be better suited for you.
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Top 9 airlines flying from Ontario to San Francisco Bay Area

Discover the top 9 airlines that operate flights from Ontario to San Francisco Bay Area. 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 10, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$26Average$82FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$31Average$91FlexibilityNo cancel feeOn-time65%
DeltaCheapest$45Average$201FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$67Average$338FlexibilityNo cancel feeOn-time75%
Avelo AirlinesCheapest$67Average$86FlexibilityNo cancel feeOn-timeN/A
Breeze AirwaysCheapest$78Average$136FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$86Average$242FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$116Average$279FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$232Average$397FlexibilityNo cancel feeOn-time71%
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