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Fremont

$39+ Cheap flights from Ontario (ONT) to Fremont, CA

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 11/19. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
out 15 — out 221
qua 10/15
qua 10/22
1 adult, Economy
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Cheapflights Tip: The best prices from Ontario to Fremont are usually found in May or February, booked 85 days in advance, depart on a Friday or Thursday and return on a Monday

Cheap flight deals from Ontario to Fremont

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

Round-trip from

$77
(United Airlines)

One-way from

$39
(United Airlines)

Popular in

November

Cheapest in

May

Average price

$137
From Ontario to Fremont
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One-way flight from Ontario to Fremont
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Highest demand for flights based on searches. 6% potential increase in price ($9 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($3 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 Ontario to Fremont

Cheapest flights from Ontario to Fremont
Explore the most affordable flight options available from Ontario to Fremont. Find the lowest fares from popular airlines and budget airlines, with prices last updated on setembro 15, 2025.

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.
sáb 10/116:51 pmONT - SFO
Nonstop1h 19mUnited Airlines
seg 10/1310:45 amSFO - ONT
Nonstop1h 28mUnited Airlines
Deal found 9/14$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.
sex 10/1010:50 pmONT - SFO
Nonstop1h 29mFrontier
sex 10/1710:43 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 9/14$78
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sex 10/1010:50 pmONT - SFO
Nonstop1h 29mFrontier
dom 10/1910:38 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 9/14$79
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
seg 10/1310:50 pmONT - SFO
Nonstop1h 29mFrontier
seg 10/2010:43 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 9/14$82
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.
sex 10/1010:50 pmONT - SFO
Nonstop1h 29mFrontier
dom 10/1210:38 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 9/14$83
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.
seg 9/229:46 pmONT - SFO
Nonstop1h 29mFrontier
seg 9/2910:11 pmSFO - ONT
Nonstop1h 27mFrontier
Deal found 9/13$86
This Cheapflightsfares deal was found by Cheapflights users on 9/15. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
qui 10/29:46 pmONT - SFO
Nonstop1h 29mFrontier
dom 10/510:11 pmSFO - ONT
Nonstop1h 27mFrontier
Deal found 9/15$91
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
qui 10/1610:40 pmONT - SFO
Nonstop1h 29mFrontier
qui 10/3010:11 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 9/14$92
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.
sex 10/2410:50 pmONT - SFO
Nonstop1h 29mFrontier
sáb 10/253:50 pmSFO - ONT
1 stop4h 52mFrontier
Deal found 9/13$97
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb 11/112:05 pmONT - SFO
1 stop10h 22mFrontier
seg 11/310:21 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 9/14$98

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to Fremont 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 setembro 15, 2025.
Use the filters below to find and compare flights from Ontario to Fremont that are best for you.

Fly from

Ontario

Fly to

Fremont

Route

Depart

Return

Price

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

sáb 10/4

6:51 pm-8:10 pm

Nonstop1h 19m

San Francisco

sáb 10/11

10:45 am-12:13 pm

Nonstop1h 28m

$77

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

dom 12/14

6:00 am-7:24 am

Nonstop1h 24m

San Francisco

dom 12/14

9:28 pm-10:49 pm

Nonstop1h 21m

$99

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

qua 10/8

6:40 am-12:20 pm

2 stops5h 40m

San Francisco

qua 10/15

5:30 am-12:20 pm

2 stops6h 50m

$129

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

seg 10/27

5:55 pm-11:45 pm

1 stop5h 50m

San Francisco

qua 10/29

3:50 pm-10:05 pm

1 stop6h 15m

$130

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

ter 9/30

6:20 am-11:25 am

1 stop5h 05m

San Francisco

ter 10/7

5:30 am-10:35 am

1 stop5h 05m

$135

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

sex 10/24

5:55 pm-11:35 pm

1 stop5h 40m

San Francisco

sáb 10/25

4:35 pm-8:50 pm

1 stop4h 15m

$135

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

qua 10/8

6:36 pm-7:55 pm

Nonstop1h 19m

San Francisco

qua 10/15

9:30 pm-10:52 pm

Nonstop1h 22m

$137

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

sáb 11/1

6:00 am-7:24 am

Nonstop1h 24m

San Francisco

sáb 11/8

9:30 pm-10:51 pm

Nonstop1h 21m

$137

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

sáb 11/1

6:38 pm-8:02 pm

Nonstop1h 24m

San Francisco

ter 11/4

9:30 pm-10:51 pm

Nonstop1h 21m

$137

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

qui 9/25

1:53 pm-3:11 pm

Nonstop1h 18m

San Francisco

seg 9/29

9:30 pm-10:52 pm

Nonstop1h 22m

$137

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/14

Showing 1-10 of 19 results
1
2

Best time to book a flight from Ontario to Fremont

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

Cheapflights Insights

Everything you need to know about your flight from Ontario to Fremont

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

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

The best time to book flights from Ontario to Fremont is 85 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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

Currently, January is the cheapest month in which you can book a flight from Ontario to Fremont (average of $276). Flying from Ontario to Fremont in June is currently the most expensive (average of $357). 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 FR8?

Find hourly flight availability from Ontario to Fremont. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated setembro 15, 2025.

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

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

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

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

Weekly flight availability from Ontario to Fremont

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

The most flights from ONT to FR8 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 (4 on average).

Reviews of airlines servicing Fremont

Get insights into the airlines that provide service to Fremont. 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 Fremont. Reviews last updated setembro 15, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest, and Delta from Ontario to Fremont by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Boarding

8.1

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

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

Comfort

7.8

Boarding

8.1

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

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.
Southwest
8.0
Very good
4,242 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Boarding

8.1

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

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

Comfort

7.8

Boarding

8.1

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

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

Comfort

7.8

Boarding

8.1

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

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

Comfort

7.8

Boarding

8.1

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

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 Ontario to Fremont. 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 Fremont?

    Located just 3.1 mi from the city center, Ontario is the airport most travelers will use when flying to Fremont from Ontario. Booking flights from Ontario (ONT) to Fremont should be relatively easy as there are 7 daily outbound flights to Fremont from 6 different airlines.

  • How popular is this Ontario to Fremont flight route?

    Within the past month, 158 users have taken a look at flights from Ontario to Fremont.

  • How long is the flight from Ontario to Fremont?

    Departing from Ontario to Fremont will take you 1h 19m. Airlines will cover a distance of 363 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    No one likes to see their flight delayed. When booking a flight from Ontario to Fremont consider choosing Emirates (87%), SkyWest Airlines (83%) or Air Canada (77%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Ontario to Fremont?

    Looking for the cheapest flight from Ontario to Fremont? While on average our users pay $556, our data indicates the cheapest price to be $39. The most popular route (Ontario - San Francisco), is priced around $53.

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

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

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

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

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

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

    Currently, January is the cheapest month in which you can book a flight from Ontario to Fremont (average of $276). Flying from Ontario to Fremont in June is currently the most expensive (average of $357). 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 6 airlines flying from Ontario to Fremont

Discover the top 6 airlines that operate flights from Ontario to Fremont. 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 setembro 15, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$31Average$86FlexibilityNo cancel feeOn-time65%
FrontierCheapest$36Average$100FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$58Average$190FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$67Average$200FlexibilityNo cancel feeOn-time75%
DeltaCheapest$97Average$207FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$101Average$288FlexibilityNo cancel feeOn-time63%

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