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$44+ Cheap flights from Fremont, CA to Ontario (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 1/5. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ONT
Jan 17 — Jan 241
Sat 1/17
Sat 1/24
1 adult, Economy
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Cheapflights Tip: The best prices from Fremont to Ontario are usually found in February or January, booked 69 days in advance, depart on a Monday or Thursday and return on a Friday

Cheap flight deals from Fremont to Ontario

Cheapest flights from Fremont to Ontario
Explore the most affordable flight options available from Fremont to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 18, 2025.

This Frontier deal was found by Cheapflights users on 12/16. 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 Frontier 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 12/16$139
This Frontier deal was found by Cheapflights users on 12/17. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/2610:44 pmSFO - ONT
Nonstop1h 28mFrontier
Mon 1/510:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/17$149
This Mytrip deal was found by Cheapflights users on 12/17. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/2910:44 pmSFO - ONT
Nonstop1h 28mFrontier
Wed 1/710:45 amONT - SFO
1 stop4h 21mFrontier
Deal found 12/17$165
This Frontier deal was found by Cheapflights users on 12/17. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/2610:44 pmSFO - ONT
Nonstop1h 28mFrontier
Wed 1/77:00 amONT - SFO
1 stop10h 59mFrontier
Deal found 12/17$175
This CheapOair deal was found by Cheapflights users on 12/17. 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.
Mon 12/2910:44 pmSFO - ONT
Nonstop1h 28mFrontier
Fri 1/210:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/17$180
This Gotogate deal was found by Cheapflights users on 12/15. 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 Gotogate 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 1/137:15 amONT - SFO
1 stop13h 31mFrontier
Deal found 12/15$184
This Super.com deal was found by Cheapflights users on 12/17. 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 Super.com 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 12/2910:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/17$186
This Expedia deal was found by Cheapflights users on 12/18. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/2610:44 pmSFO - ONT
Nonstop1h 28mFrontier
Sun 12/2810:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/18$188
This Frontier deal was found by Cheapflights users on 12/18. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/2610:44 pmSFO - ONT
Nonstop1h 28mFrontier
Mon 12/2910:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/18$189
This Super.com deal was found by Cheapflights users on 12/16. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2810:31 pmSFO - ONT
Nonstop1h 28mFrontier
Fri 1/210:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/16$196
This CheapOair deal was found by Cheapflights users on 12/16. 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.
Mon 12/2210:44 pmSFO - ONT
Nonstop1h 28mFrontier
Mon 1/510:12 pmONT - SFO
Nonstop1h 40mFrontier
Deal found 12/16$204

Find flight deals from Fremont to Ontario

Keep the following information in mind while searching for Fremont to Ontario flight deals. Data was last updated December 18, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$109
(CheapOair)

One-way from

$44
(Frontier)

Popular in

December

Cheapest in

February

Average price

$221
Provider with most accurate pricing for San Francisco-Los Angeles flight deals.
Search Deals
Provider most trusted by Cheapflights users for San Francisco-Los Angeles flights.
Search Deals
From Fremont to Ontario
Search Deals
One-way flight from Fremont to Ontario
Search Deals
Highest demand for flights based on searches. 12% potential increase in price ($23 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

Cheapflights Fare Finder

 
Customize your flight search to find flights from Fremont 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 18, 2025.
Use the filters below to find and compare flights from Fremont to Ontario that are best for you.

Fly from

Fremont

Fly to

Ontario

Route

Depart

Return

Price

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 2/5

10:30 am-11:58 pm

2 stops13h 28m

Ontario

Sat 2/7

6:00 am-11:30 pm

2 stops17h 30m

$236

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 1/7

9:30 pm-10:53 pm

Nonstop1h 23m

Ontario

Sat 1/10

6:32 pm-8:19 pm

Nonstop1h 47m

$252

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Mon 3/9

9:30 pm-10:57 pm

Nonstop1h 27m

Ontario

Thu 3/12

6:37 pm-8:10 pm

Nonstop1h 33m

$259

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 1/31

2:30 pm-8:36 pm

1 stop6h 06m

Ontario

Sat 2/7

11:53 am-5:59 pm

1 stop6h 06m

$264

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Fri 1/30

2:30 pm-11:56 pm

1 stop9h 26m

Ontario

Mon 2/2

6:00 am-5:59 pm

1 stop11h 59m

$264

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 1/24

9:30 pm-10:53 pm

Nonstop1h 23m

Ontario

Sat 1/31

1:53 pm-3:25 pm

Nonstop1h 32m

$273

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 1/17

10:55 am-12:17 pm

Nonstop1h 22m

Ontario

Thu 1/22

1:53 pm-3:25 pm

Nonstop1h 32m

$273

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Thu 1/8

9:30 pm-10:53 pm

Nonstop1h 23m

Ontario

Sat 1/10

6:00 am-7:32 am

Nonstop1h 32m

$273

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 1/31

9:30 pm-10:53 pm

Nonstop1h 23m

Ontario

Mon 2/2

1:53 pm-3:25 pm

Nonstop1h 32m

$273

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Fri 2/27

6:30 am-11:32 pm

1 stop17h 02m

Ontario

Fri 3/6

6:14 am-10:56 pm

1 stop16h 42m

$284

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/17

Showing 1-10 of 22 results
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Best time to book a flight from Fremont to Ontario

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

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

Use this chart to determine the optimal time to book a round-trip flight from Fremont to Ontario. Price data was last updated on December 12, 2025.

The price you pay for your flight from Fremont to Ontario may vary depending on when you book. For the best chance of a lower fare, look to book 69 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Fremont to Ontario?

Currently, February is the cheapest month in which you can book a flight from Fremont to Ontario (average of $19). Flying from Fremont to Ontario in September is currently the most expensive (average of $60). 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 FR8 to ONT?

Find hourly flight availability from Fremont 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 18, 2025.

One of the essential ways to save on airfare from Fremont to Ontario is to remain as flexible as possible. Flights that are in the afternoon tend to be the most expensive. A flight in the morning could potentially save you up to 21% on airfare.

What is the cheapest day to fly from Fremont to Ontario?

Use this chart to determine the cheapest time to fly round-trip from Fremont to Ontario. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Fremont to Ontario flight should consider departing on Saturday mornings 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.

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 18, 2025.
See what other customers who have flown with Alaska Airlines, Delta, and United Airlines from Fremont to Ontario have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
11,477 reviews

Entertainment

7.0

Boarding

8.1

Overall

8.0

Food

7.1

Crew

8.5

Comfort

7.8

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
11,477 reviews
Alaska Airlines
8.0
Very good
11,477 reviews

Entertainment

7.0

Boarding

8.1

Overall

8.0

Food

7.1

Crew

8.5

Comfort

7.8

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
8,005 reviews
Alaska Airlines
8.0
Very good
11,477 reviews

Entertainment

7.0

Boarding

8.1

Overall

8.0

Food

7.1

Crew

8.5

Comfort

7.8

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
9,092 reviews
Alaska Airlines
8.0
Very good
11,477 reviews

Entertainment

7.0

Boarding

8.1

Overall

8.0

Food

7.1

Crew

8.5

Comfort

7.8

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
11,055 reviews
Alaska Airlines
8.0
Very good
11,477 reviews

Entertainment

7.0

Boarding

8.1

Overall

8.0

Food

7.1

Crew

8.5

Comfort

7.8

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
3,081 reviews
Alaska Airlines
8.0
Very good
11,477 reviews

Entertainment

7.0

Boarding

8.1

Overall

8.0

Food

7.1

Crew

8.5

Comfort

7.8

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 Fremont to Ontario. 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 into for flights to Ontario from Fremont?

    For a flight from Fremont to Ontario, you will be flying into Ontario. Ontario (ONT) is just 3.1 mi from the center of the city. Ontario is the only Ontario airport and it handles 1 inbound flight from Fremont per day. 7 airlines have flights to Ontario from Fremont on a regular basis.

  • How popular is this Fremont to Ontario flight route?

    The Fremont to Ontario flight path was viewed by 55 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • How long is the flight from Fremont to Ontario?

    For as low as $252, Delta can have you in Ontario from Fremont in 1h 23m. The distance from Fremont to Ontario is about 363 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $26. Users have also found prices from $28 and $58 on United Airlines and Alaska Airlines, respectively.

  • What are the most reliable airlines from Fremont to Ontario?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Fremont to Ontario on time: SkyWest Airlines (100%), Emirates (86%), United Airlines (86%).

  • What are the cheapest flights from Fremont to Ontario?

    While on average a flight from Fremont to Ontario is generally $158, our data shows the cheapest flight currently is $34. When looking at the most popular route, (San Francisco - Ontario), you can expect to pay $130 for that flight.

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

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

  • How can I find direct flights from Fremont to Ontario?

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

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

    Yes. Cheapflights offers flight deals from Fremont 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 Fremont to Ontario?

    Currently, February is the cheapest month in which you can book a flight from Fremont to Ontario (average of $19). Flying from Fremont to Ontario in September is currently the most expensive (average of $60). 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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Top 7 airlines flying from Fremont to Ontario

Discover the top 7 airlines that operate flights from Fremont 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 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$27Average$125FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$46Average$88FlexibilityNo cancel feeOn-time65%
United AirlinesCheapest$58Average$216FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$59Average$215FlexibilityNo cancel feeOn-time75%
DeltaCheapest$98Average$200FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$112Average$272FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$186Average$206FlexibilityNo cancel feeOn-time71%

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