HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
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 12/6. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
Dec 3 — Dec 101
Wed 12/3
Wed 12/10
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Ontario to Fremont with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Ontario to Fremont are usually found in May or February, booked 74 days in advance, depart on a Friday or Thursday and return on a Monday

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 November 3, 2025.

This United Airlines deal was found by Cheapflights users on 11/1. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/36:00 amONT - SFO
Nonstop1h 24mUnited Airlines
Sat 12/64:16 pmSFO - ONT
Nonstop1h 21mUnited Airlines
Deal found 11/1$77
This Frontier deal was found by Cheapflights users on 11/2. 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.
Thu 12/46:15 amONT - SFO
1 stop15h 48mFrontier
Mon 12/810:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/2$84
This Kiwi.com deal was found by Cheapflights users on 11/1. 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.
Fri 11/1410:42 pmONT - SFO
Nonstop1h 29mFrontier
Mon 12/810:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/1$87
This CheapOair deal was found by Cheapflights users on 11/2. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/1710:42 pmONT - SFO
Nonstop1h 29mFrontier
Tue 11/188:02 amSFO - ONT
1 stop13h 25mFrontier
Deal found 11/2$88
This CheapOair deal was found by Cheapflights users on 11/2. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/1410:42 pmONT - SFO
Nonstop1h 29mFrontier
Mon 11/1710:21 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 11/2$92
This Frontier deal was found by Cheapflights users on 11/1. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/229:59 pmONT - SFO
Nonstop1h 30mFrontier
Fri 12/510:20 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/1$94
This Mytrip deal was found by Cheapflights users on 11/2. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/510:12 pmONT - SFO
Nonstop1h 40mFrontier
Sun 12/76:30 amSFO - ONT
1 stop8h 36mFrontier
Deal found 11/2$98
This Frontier deal was found by Cheapflights users on 11/2. 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.
Mon 11/249:59 pmONT - SFO
Nonstop1h 30mFrontier
Fri 12/510:20 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/2$99
This CheapOair deal was found by Cheapflights users on 10/31. 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 11/1710:42 pmONT - SFO
Nonstop1h 29mFrontier
Sun 11/2310:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 10/31$102
This CheapOair deal was found by Cheapflights users on 10/31. 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 11/1010:42 pmONT - SFO
Nonstop1h 29mFrontier
Fri 11/1410:21 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 10/31$104
This CheapOair deal was found by Cheapflights users on 11/1. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/1110:12 pmONT - SFO
Nonstop1h 40mFrontier
Sun 12/1410:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/1$105
This CheapOair deal was found by Cheapflights users on 10/31. 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.
Thu 11/1310:42 pmONT - SFO
Nonstop1h 29mFrontier
Fri 11/1410:21 pmSFO - ONT
Nonstop1h 29mFrontier
Deal found 10/31$106

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 November 3, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$77
(United Airlines)

One-way from

$39
(United Airlines)

Popular in

November

Cheapest in

May

Average price

$167
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. 12% potential increase in price ($17 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($4 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2025
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 November 3, 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

Thu 12/4

6:00 am-7:24 am

Nonstop1h 24m

San Francisco

Mon 12/8

9:28 pm-10:49 pm

Nonstop1h 21m

$137

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Mon 12/15

1:50 pm-3:14 pm

Nonstop1h 24m

San Francisco

Wed 12/17

10:55 am-12:17 pm

Nonstop1h 22m

$137

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 12/3

1:50 pm-3:14 pm

Nonstop1h 24m

San Francisco

Thu 12/4

10:55 am-12:18 pm

Nonstop1h 23m

$137

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 12/6

6:00 am-7:24 am

Nonstop1h 24m

San Francisco

Mon 12/8

9:28 pm-10:49 pm

Nonstop1h 21m

$137

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 11/20

6:30 am-4:03 pm

1 stop9h 33m

San Francisco

Tue 11/25

10:03 pm-11:31 pm

Nonstop1h 28m

$140

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 12/10

6:50 am-3:05 pm

2 stops8h 15m

San Francisco

Sat 12/13

5:00 am-11:30 am

1 stop6h 30m

$156

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Wed 12/3

6:00 am-7:24 am

Nonstop1h 24m

San Francisco

Sat 12/13

9:28 pm-10:49 pm

Nonstop1h 21m

$184

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 11/14

6:00 am-7:24 am

Nonstop1h 24m

San Francisco

Wed 12/3

9:28 pm-10:49 pm

Nonstop1h 21m

$192

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Sat 12/13

6:00 am-7:24 am

Nonstop1h 24m

San Francisco

Sun 12/14

9:28 pm-10:49 pm

Nonstop1h 21m

$212

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Fri 1/16

6:00 am-7:32 am

Nonstop1h 32m

San Francisco

Sat 1/17

9:30 pm-10:53 pm

Nonstop1h 23m

$215

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/2

Showing 1-10 of 22 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 October 31, 2025.

The best time to book flights from Ontario to Fremont is 74 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, December is the cheapest month in which you can book a flight from Ontario to Fremont (average of $17). Flying from Ontario to Fremont in August is currently the most expensive (average of $57). 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 November 3, 2025.

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 19% versus a flight at noon.

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 Monday afternoons 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 November 3, 2025.

The most flights from ONT to FR8 are scheduled on a Sunday (9 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (5 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 November 3, 2025.
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
11,236 reviews

Entertainment

7.0

Overall

8.0

Comfort

7.8

Crew

8.5

Boarding

8.1

Food

7.1

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
11,236 reviews
Alaska Airlines
8.0
Very good
11,236 reviews

Entertainment

7.0

Overall

8.0

Comfort

7.8

Crew

8.5

Boarding

8.1

Food

7.1

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.
Southwest
8.0
Very good
4,238 reviews
Alaska Airlines
8.0
Very good
11,236 reviews

Entertainment

7.0

Overall

8.0

Comfort

7.8

Crew

8.5

Boarding

8.1

Food

7.1

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
8,996 reviews
Alaska Airlines
8.0
Very good
11,236 reviews

Entertainment

7.0

Overall

8.0

Comfort

7.8

Crew

8.5

Boarding

8.1

Food

7.1

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
3,117 reviews
Alaska Airlines
8.0
Very good
11,236 reviews

Entertainment

7.0

Overall

8.0

Comfort

7.8

Crew

8.5

Boarding

8.1

Food

7.1

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 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 5 different airlines.

  • How popular is this Ontario to Fremont flight route?

    Within the past month, 157 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 24m. Airlines will cover a distance of 363 mi. Generally, flights for this route are nonstop.

  • 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 (83%), United Airlines (71%) or Air Canada (66%) 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 $439, our data indicates the cheapest price to be $38. The most popular route (Ontario - San Francisco), is priced around $77.

  • 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, December is the cheapest month in which you can book a flight from Ontario to Fremont (average of $17). Flying from Ontario to Fremont in August is currently the most expensive (average of $57). 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Ontario to Fremont

See prices for flight routes from nearby airports that may be better suited for you.
San Francisco to Los Angeles flights
Los Angeles to San Francisco flights
San Francisco to Ontario flights
San Francisco to Las Vegas flights
Ontario to San Francisco flights
San Francisco to Santa Ana flights
Los Angeles to Las Vegas flights
Burbank to Las Vegas flights
San Jose to Los Angeles flights
Santa Ana to San Francisco flights
San Jose to Las Vegas flights
Santa Ana to Las Vegas flights
Los Angeles to San Jose flights
Sacramento to Los Angeles flights
San Francisco to San Diego flights
Ontario to Las Vegas flights
San Diego to San Francisco flights
Sacramento to Las Vegas flights
San Diego to Las Vegas flights
Oakland to Las Vegas flights
San Francisco to Burbank flights
Los Angeles to Sacramento flights
Burbank to San Francisco flights
San Francisco to Palm Springs flights
San Jose to Ontario flights
Las Vegas to Los Angeles flights
Fresno to Las Vegas flights
Reno to Las Vegas flights
Ontario to Sacramento flights
Sacramento to Ontario flights
Las Vegas to Burbank flights
Las Vegas to San Francisco flights
Ontario to San Jose flights
Las Vegas to San Diego flights
Los Angeles to Reno flights
San Diego to San Jose flights
Sacramento to San Diego flights
San Jose to Santa Ana flights
San Jose to San Diego flights
Palm Springs to San Francisco flights
Santa Ana to San Jose flights
Oakland to Los Angeles flights
Santa Ana to Sacramento flights
Stockton to Las Vegas flights
Las Vegas to Santa Ana flights
Sacramento to Santa Ana flights
Reno to Los Angeles flights
San Francisco to Long Beach flights
Long Beach to San Francisco flights
San Jose to Palm Springs flights

Top 5 airlines flying from Ontario to Fremont

Discover the top 5 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 November 3, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$34Average$104FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$48Average$85FlexibilityNo cancel feeOn-time65%
United AirlinesCheapest$58Average$184FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$67Average$187FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$97Average$289FlexibilityNo cancel feeOn-time63%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.
Site
©2025 Cheapflights