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$49+ 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 10/8. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
Aug 5 — Aug 121
Tue 8/5
Tue 8/12
1 adult, Economy
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Cheapflights Tip: The best prices from Ontario to Fremont are usually found in May or September, booked 89 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 July 31, 2025.

Round-trip from

$88
(Cheapflightsfares)

One-way from

$49
(United Airlines)

Popular in

November

Cheapest in

May

Average price

$135
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. 10% potential increase in price ($14 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($4 potential savings vs. average RT price).
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Average for round-trip flights in July 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 July 31, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 7/29. 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 10/129:41 pmONT - SFO
Nonstop1h 32mFrontier
Mon 10/1310:11 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 7/29$88
This United Airlines deal was found by Cheapflights users on 7/29. 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 8/196:00 amONT - SFO
Nonstop1h 19mUnited Airlines
Tue 8/194:17 pmSFO - ONT
Nonstop1h 20mUnited Airlines
Deal found 7/29$97

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 July 31, 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

Sun 10/12

9:41 pm-11:13 pm

Nonstop1h 32m

San Francisco

Mon 10/13

10:11 pm-11:40 pm

Nonstop1h 29m

$88

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 8/19

1:42 pm-3:01 pm

Nonstop1h 19m

San Francisco

Wed 8/20

7:10 pm-8:33 pm

Nonstop1h 23m

$97

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 10/8

1:53 pm-3:11 pm

Nonstop1h 18m

$49

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Mon 8/11

9:41 pm-11:14 pm

Nonstop1h 33m

$54

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 8/12

5:45 am-9:50 am

1 stop4h 05m

$99

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/31

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 July 25, 2025.

The best time to book flights from Ontario to Fremont is 89 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 $358). 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 July 31, 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 Wednesday evenings when fares are most often at their lowest. Sunday at noon 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 July 31, 2025.

The most flights from ONT to FR8 are scheduled on a Thursday (8 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (2 on average).

How much does it cost to fly round-trip from Ontario to Fremont?

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 July 31, 2025.
Get a feel of what it's like to fly with Southwest, United Airlines, and Frontier 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.
Southwest
8.0
Very good
4,244 reviews

Crew

8.6

Overall

8.0

Food

7.0

Boarding

8.1

Comfort

8.0

Entertainment

7.5

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
8.0
Very good
4,244 reviews
Southwest
8.0
Very good
4,244 reviews

Crew

8.6

Overall

8.0

Food

7.0

Boarding

8.1

Comfort

8.0

Entertainment

7.5

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
8,902 reviews
Southwest
8.0
Very good
4,244 reviews

Crew

8.6

Overall

8.0

Food

7.0

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
Frontier
5.9
Fair
3,238 reviews
Southwest
8.0
Very good
4,244 reviews

Crew

8.6

Overall

8.0

Food

7.0

Boarding

8.1

Comfort

8.0

Entertainment

7.5

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 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 3 daily outbound flights to Fremont from 6 different airlines.

  • How popular is this Ontario to Fremont flight route?

    Within the past month, 176 users have taken a look at flights from Ontario to Fremont.

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

    $49 is the cheapest one-way deal found within the past few days, from United Airlines. You may also be able to find cheap deals on Frontier and Southwest, with prices starting from $54 and $99, respectively.

  • 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 (91%), SkyWest Airlines (89%) or Copa Airlines (88%) 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 $376, our data indicates the cheapest price to be $41. The most popular route (Ontario - San Francisco), is priced around $67.

  • 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 $358). 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 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 July 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$20Average$91FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$37Average$81FlexibilityNo cancel feeOn-time65%
United AirlinesCheapest$58Average$193FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$67Average$206FlexibilityNo cancel feeOn-time75%
DeltaCheapest$85Average$197FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$114Average$289FlexibilityNo cancel feeOn-time63%

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