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$39+ 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 11/8. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ONT
Oct 15 — Oct 221
Wed 10/15
Wed 10/22
1 adult, Economy
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Cheapflights Tip: The best prices from Fremont to Ontario are usually found in February or October, booked 89 days in advance, depart on a Monday or Saturday and return on a Friday

Cheap flight deals from Fremont to Ontario

Keep the following information in mind while searching for Fremont to Ontario flight deals. Data was last updated September 15, 2025.

Round-trip from

$72
(Cheapflightsfares)

One-way from

$39
(United Airlines)

Popular in

December

Cheapest in

February

Average price

$137
From Fremont to Ontario
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One-way flight from Fremont to Ontario
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Highest demand for flights based on searches. 11% potential increase in price ($20 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($8 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find 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 September 15, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 9/12. 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 9/2910:11 pmSFO - ONT
Nonstop1h 27mFrontier
Thu 10/29:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/12$72
This Flightnetwork deal was found by Cheapflights users on 9/14. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/1510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 9/229:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/14$74
This United Airlines deal was found by Cheapflights users on 9/13. 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 10/69:30 pmSFO - ONT
Nonstop1h 22mUnited Airlines
Sat 10/116:51 pmONT - SFO
Nonstop1h 19mUnited Airlines
Deal found 9/13$77
This Cheapflightsfares deal was found by Cheapflights users on 9/14. 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 10/1210:38 pmSFO - ONT
Nonstop1h 29mFrontier
Sun 10/1910:40 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/14$78
This Frontier deal was found by Cheapflights users on 9/13. 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 10/1710:43 pmSFO - ONT
Nonstop1h 29mFrontier
Fri 10/2410:50 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/13$79
This Cheapflightsfares deal was found by Cheapflights users on 9/14. 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 9/2510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Thu 10/29:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/14$82
This Cheapflightsfares deal was found by Cheapflights users on 9/13. 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.
Fri 11/1410:21 pmSFO - ONT
Nonstop1h 29mFrontier
Sun 11/1610:50 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/13$83
This Cheapflightsfares deal was found by Cheapflights users on 9/14. 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.
Fri 9/2610:11 pmSFO - ONT
Nonstop1h 27mFrontier
Mon 9/299:46 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/14$86
This United Airlines deal was found by Cheapflights users on 9/14. 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.
Tue 11/184:13 pmSFO - ONT
Nonstop1h 21mUnited Airlines
Sat 11/226:00 amONT - SFO
Nonstop1h 24mUnited Airlines
Deal found 9/14$88
This Cheapflightsfares deal was found by Cheapflights users on 9/14. 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 11/610:11 pmSFO - ONT
Nonstop1h 29mFrontier
Mon 11/1010:40 pmONT - SFO
Nonstop1h 29mFrontier
Deal found 9/14$91

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 September 15, 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

Sat 10/25

9:30 pm-10:52 pm

Nonstop1h 22m

Ontario

Wed 10/29

6:38 pm-8:02 pm

Nonstop1h 24m

$77

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 11/15

5:00 am-11:30 am

1 stop6h 30m

Ontario

Mon 11/17

3:30 pm-9:50 pm

1 stop6h 20m

$135

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Mon 10/13

10:45 am-12:13 pm

Nonstop1h 28m

Ontario

Tue 10/14

9:36 am-10:55 am

Nonstop1h 19m

$137

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 10/29

9:30 pm-10:51 pm

Nonstop1h 21m

Ontario

Thu 10/30

1:40 pm-3:04 pm

Nonstop1h 24m

$137

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Mon 10/6

9:30 pm-10:52 pm

Nonstop1h 22m

Ontario

Wed 10/15

6:36 pm-7:55 pm

Nonstop1h 19m

$137

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 11/15

4:13 pm-5:34 pm

Nonstop1h 21m

Ontario

Sun 11/16

6:00 am-7:24 am

Nonstop1h 24m

$137

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 10/15

9:30 pm-10:52 pm

Nonstop1h 22m

Ontario

Thu 10/16

1:53 pm-3:11 pm

Nonstop1h 18m

$137

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Sat 10/11

9:30 pm-10:52 pm

Nonstop1h 22m

Ontario

Fri 10/17

9:36 am-10:55 am

Nonstop1h 19m

$137

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Tue 10/7

4:20 pm-5:40 pm

Nonstop1h 20m

Ontario

Thu 10/16

1:53 pm-3:11 pm

Nonstop1h 18m

$137

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Tue 10/7

4:20 pm-5:40 pm

Nonstop1h 20m

Ontario

Sat 10/11

1:53 pm-3:11 pm

Nonstop1h 18m

$137

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/15

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 September 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 89 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, August is the cheapest month in which you can book a flight from Fremont to Ontario (average of $246). Flying from Fremont to Ontario in March is currently the most expensive (average of $328). 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 September 15, 2025.

When flying from Fremont to Ontario, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

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 evenings when fares are most often at their lowest. Friday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Fremont to Ontario

Explore weekly flight availability from Fremont to Ontario. 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 September 15, 2025.

The most flights from FR8 to ONT are scheduled on a Friday (11 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (3 on average).

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 September 15, 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
10,000 reviews

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

Food

7.1

Boarding

8.1

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
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

Food

7.1

Boarding

8.1

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
8.0
Very good
7,954 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

Food

7.1

Boarding

8.1

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
8,929 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

Food

7.1

Boarding

8.1

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.
Spirit Airlines
6.3
Okay
8,015 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

Food

7.1

Boarding

8.1

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
3,172 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

Food

7.1

Boarding

8.1

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 6 inbound flights 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 72 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 $77, United Airlines can have you in Ontario from Fremont in 1h 22m. 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 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 (83%), United Airlines (82%), Air Canada (79%).

  • What are the cheapest flights from Fremont to Ontario?

    While on average a flight from Fremont to Ontario is generally $123, our data shows the cheapest flight currently is $38. When looking at the most popular route, (San Francisco - Ontario), you can expect to pay $53 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, August is the cheapest month in which you can book a flight from Fremont to Ontario (average of $246). Flying from Fremont to Ontario in March is currently the most expensive (average of $328). 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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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 September 15, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$24Average$109FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$42Average$89FlexibilityNo cancel feeOn-time65%
United AirlinesCheapest$58Average$186FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$59Average$229FlexibilityNo cancel feeOn-time75%
DeltaCheapest$75Average$193FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$134Average$275FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$186Average$221FlexibilityNo cancel feeOn-time71%

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