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Fremont

$78+ 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 4/23. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
Mar 5 — Mar 121
Thu 3/5
Thu 3/12
1 adult, Economy
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1. Tell us where you want to go

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Cheapflights Tip: The best prices from Ontario to Fremont are usually found in May or April, booked 37 days in advance, depart on a Friday or Thursday and return on a Monday

Cheap 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 February 3, 2026.

This Kiwi.com deal was found by Cheapflights users on 2/3. 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.
Tue 2/248:35 am
ONT
-
SFO
1 stop13h 26m
Frontier
Sun 3/12:10 pm
SFO
-
ONT
1 stop23h 01m
Frontier
Deal found 2/3$143
This Expedia deal was found by Cheapflights users on 2/2. 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.
Tue 3/38:40 am
ONT
-
SFO
1 stop13h 21m
Frontier
Wed 4/110:14 pm
SFO
-
ONT
1 stop9h 50m
Frontier
Deal found 2/2$144
This Flightnetwork deal was found by Cheapflights users on 2/3. 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 2/233:28 pm
ONT
-
SFO
1 stop26h 52m
Frontier
Wed 2/257:20 am
SFO
-
ONT
1 stop26h 14m
Frontier
Deal found 2/3$145
This Gotogate deal was found by Cheapflights users on 2/2. 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.
Thu 2/263:24 pm
ONT
-
SFO
1 stop4h 15m
Frontier
Mon 3/29:03 am
SFO
-
ONT
1 stop4h 08m
Frontier
Deal found 2/2$147
This Mytrip deal was found by Cheapflights users on 2/3. 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.
Fri 3/69:06 am
ONT
-
SFO
Nonstop1h 42m
Frontier
Sat 3/76:00 am
SFO
-
ONT
1 stop17h 59m
Frontier
Deal found 2/3$149
This Mytrip deal was found by Cheapflights users on 2/3. 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 3/23:28 pm
ONT
-
SFO
1 stop26h 52m
Frontier
Wed 3/47:15 pm
SFO
-
ONT
1 stop17h 56m
Frontier
Deal found 2/3$150
This Frontier deal was found by Cheapflights users on 2/2. 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.
Tue 3/242:23 pm
ONT
-
SFO
1 stop4h 14m
Frontier
Fri 4/38:48 am
SFO
-
ONT
Nonstop1h 32m
Frontier
Deal found 2/2$151
This Super.com deal was found by Cheapflights users on 2/2. 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.
Wed 3/42:06 pm
ONT
-
SFO
1 stop19h 47m
Frontier
Wed 3/119:04 pm
SFO
-
ONT
1 stop26h 55m
Frontier
Deal found 2/2$152
This Frontier deal was found by Cheapflights users on 2/3. 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.
Tue 4/71:09 pm
ONT
-
SFO
1 stop4h 25m
Frontier
Mon 4/138:48 am
SFO
-
ONT
Nonstop1h 32m
Frontier
Deal found 2/3$154
This Frontier deal was found by Cheapflights users on 2/3. 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.
Thu 4/165:33 pm
ONT
-
SFO
1 stop6h 49m
Frontier
Sun 4/199:23 am
SFO
-
ONT
Nonstop1h 29m
Frontier
Deal found 2/3$155
This Kiwi.com deal was found by Cheapflights users on 2/1. 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.
Tue 3/38:40 am
ONT
-
SFO
1 stop13h 21m
Frontier
Fri 3/66:00 am
SFO
-
ONT
1 stop17h 59m
Frontier
Deal found 2/1$156

Find flight deals from Ontario to Fremont

Keep the following information in mind while searching for Ontario to Fremont flight deals. Data was last updated February 3, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$143
(Kiwi.com)

One-way from

$78
(Super.com)

Popular in

November

Cheapest in

May

Average price

$138
Provider with most accurate pricing for Los Angeles-San Francisco flight deals.
Search Deals
Provider most trusted by Cheapflights users for Los Angeles-San Francisco flights.
Search Deals
From Ontario to Fremont
Search Deals
One-way flight from Ontario to Fremont
Search Deals
Highest demand for flights based on searches. 21% potential increase in price ($39 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($6 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2026
Search Deals

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 February 3, 2026.
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

Fri 2/20

6:00 am-12:28 am

1 stop18h 28m

San Francisco

Sun 2/22

8:34 pm-5:48 pm

1 stop21h 14m

$253

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 3/7

6:37 pm-8:10 pm

Nonstop1h 33m

San Francisco

Sun 3/8

10:50 am-12:18 pm

Nonstop1h 28m

$259

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 4/25

1:27 pm-2:57 pm

Nonstop1h 30m

San Francisco

Mon 4/27

10:44 am-12:14 pm

Nonstop1h 30m

$275

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 3/11

1:40 pm-3:13 pm

Nonstop1h 33m

San Francisco

Wed 3/11

9:30 pm-10:57 pm

Nonstop1h 27m

$279

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 3/4

1:50 pm-3:23 pm

Nonstop1h 33m

San Francisco

Wed 3/4

9:30 pm-10:57 pm

Nonstop1h 27m

$279

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 2/28

6:10 am-7:43 am

Nonstop1h 33m

San Francisco

Sun 3/1

4:13 pm-5:41 pm

Nonstop1h 28m

$279

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 3/27

4:25 pm-9:35 pm

1 stop5h 10m

San Francisco

Mon 3/30

5:40 pm-11:35 pm

1 stop5h 55m

$289

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 3/18

6:00 am-6:44 pm

1 stop12h 44m

San Francisco

Tue 3/24

7:29 pm-11:18 am

1 stop15h 49m

$293

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 3/4

5:55 am-2:35 pm

2 stops8h 40m

San Francisco

Thu 3/5

9:25 am-3:45 pm

1 stop6h 20m

$294

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Tue 4/7

11:05 am-12:35 pm

Nonstop1h 30m

San Francisco

Fri 4/10

9:09 pm-10:45 pm

Nonstop1h 36m

$297

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/3

Showing 1-10 of 24 results
1
2
3

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 January 30, 2026.

The best time to book flights from Ontario to Fremont is 37 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, February is the cheapest month in which you can book a flight from Ontario to Fremont (average of $19). Flying from Ontario to Fremont in November is currently the most expensive (average of $62). 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 February 3, 2026.

When flying from Ontario to Fremont, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 26% versus a flight in the afternoon.

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 January 31, 2026.

Travelers seeking maximum savings on their Ontario to Fremont flight should consider departing on Saturday at noon 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 February 3, 2026.

The most flights from ONT to FR8 are scheduled on a Monday (4 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (1 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 February 3, 2026.
Get a feel of what it's like to fly with Alaska Airlines, Southwest, and United Airlines 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
11,835 reviews

Comfort

7.8

Crew

8.5

Overall

8.0

Entertainment

7.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
Alaska Airlines
8.0
Very good
11,835 reviews
Alaska Airlines
8.0
Very good
11,835 reviews

Comfort

7.8

Crew

8.5

Overall

8.0

Entertainment

7.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
Southwest
8.0
Very good
4,273 reviews
Alaska Airlines
8.0
Very good
11,835 reviews

Comfort

7.8

Crew

8.5

Overall

8.0

Entertainment

7.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
United Airlines
7.4
Good
9,235 reviews
Alaska Airlines
8.0
Very good
11,835 reviews

Comfort

7.8

Crew

8.5

Overall

8.0

Entertainment

7.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
Frontier
5.7
Fair
3,051 reviews
Alaska Airlines
8.0
Very good
11,835 reviews

Comfort

7.8

Crew

8.5

Overall

8.0

Entertainment

7.0

Boarding

8.1

Food

7.1

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading

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 4 different airlines.

  • How popular is this Ontario to Fremont flight route?

    Within the past month, 116 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 33m. 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 cheapest airlines to fly from Ontario to Fremont one-way?

    $27 is the cheapest one-way deal found within the past few days, from Frontier. You may also be able to find cheap deals on United Airlines and Delta, with prices starting from $38 and $51, 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 United Airlines (86%), SkyWest Airlines (82%) or Air Canada (74%) 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 $802, our data indicates the cheapest price to be $76. The most popular route (Ontario - San Francisco), is priced around $132.

  • 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, February is the cheapest month in which you can book a flight from Ontario to Fremont (average of $19). Flying from Ontario to Fremont in November is currently the most expensive (average of $62). 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 4 airlines flying from Ontario to Fremont

Discover the top 4 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 February 3, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$31Average$103FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$58Average$186FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$67Average$173FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$97Average$271FlexibilityNo cancel feeOn-time63%

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