HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$84+ 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 2/21. Fares are subject to change and may not be available on all flights or dates of travel.
SFO — ONT
Mar 5 — Mar 121
Thu 3/5
Thu 3/12
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Fremont to Ontario 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 Fremont to Ontario are usually found in May or June, booked 36 days in advance, depart on a Monday or Thursday and return on a Friday

Cheap 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 February 3, 2026.

This CheapOair 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/98:43 am
SFO
-
ONT
Nonstop1h 29m
Frontier
Tue 3/106:15 am
ONT
-
SFO
1 stop13h 54m
Frontier
Deal found 2/3$125
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.
Thu 4/239:23 am
SFO
-
ONT
Nonstop1h 29m
Frontier
Sun 4/269:02 am
ONT
-
SFO
Nonstop1h 35m
Frontier
Deal found 2/2$127
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.
Thu 4/239:23 am
SFO
-
ONT
Nonstop1h 29m
Frontier
Sun 5/109:02 am
ONT
-
SFO
Nonstop1h 35m
Frontier
Deal found 2/2$128
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.
Fri 3/208:53 am
SFO
-
ONT
Nonstop1h 29m
Frontier
Fri 3/279:06 am
ONT
-
SFO
Nonstop1h 42m
Frontier
Deal found 2/2$129
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.
Sat 4/182:01 pm
SFO
-
ONT
1 stop4h 22m
Frontier
Sun 4/199:02 am
ONT
-
SFO
Nonstop1h 35m
Frontier
Deal found 2/2$131
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.
Sun 4/58:33 am
SFO
-
ONT
Nonstop1h 32m
Frontier
Sun 4/128:49 am
ONT
-
SFO
Nonstop1h 41m
Frontier
Deal found 2/2$132
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 4/239:23 am
SFO
-
ONT
Nonstop1h 29m
Frontier
Sun 4/2612:59 am
ONT
-
SFO
1 stop8h 09m
Frontier
Deal found 2/3$133
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.
Sat 3/76:00 am
SFO
-
ONT
1 stop17h 59m
Frontier
Mon 3/99:06 am
ONT
-
SFO
Nonstop1h 42m
Frontier
Deal found 2/3$134
This CheapOair 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/68:43 am
SFO
-
ONT
Nonstop1h 29m
Frontier
Tue 3/106:15 am
ONT
-
SFO
1 stop13h 54m
Frontier
Deal found 2/3$135
This Expedia 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/2610:48 am
SFO
-
ONT
1 stop26h 38m
Frontier
Wed 3/47:17 pm
ONT
-
SFO
1 stop14h 36m
Frontier
Deal found 2/1$138
This Booking.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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/58:43 am
SFO
-
ONT
1 stop4h 28m
Frontier
Mon 3/99:06 am
ONT
-
SFO
Nonstop1h 42m
Frontier
Deal found 2/2$140

Find flight deals from Fremont to Ontario

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

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$118
(Frontier)

One-way from

$84
(Super.com)

Popular in

December

Cheapest in

May

Average price

$165
Provider with most accurate pricing for San Francisco-Los Angeles flight deals.
Search Deals
Provider most trusted by Cheapflights users for San Francisco-Los Angeles flights.
Search Deals
From Fremont to Ontario
Search Deals
One-way flight from Fremont to Ontario
Search Deals
Highest demand for flights based on searches. 18% potential increase in price ($38 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($5 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 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 February 3, 2026.
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

Tue 3/3

11:10 am-12:38 pm

Nonstop1h 28m

Ontario

Tue 3/10

6:15 am-7:48 am

Nonstop1h 33m

$219

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 3/4

4:13 pm-5:41 pm

Nonstop1h 28m

Ontario

Tue 3/10

6:15 am-7:48 am

Nonstop1h 33m

$219

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 3/25

9:30 pm-10:57 pm

Nonstop1h 27m

Ontario

Sat 3/28

6:15 am-7:48 am

Nonstop1h 33m

$239

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Mon 3/9

4:10 pm-5:35 pm

Nonstop1h 25m

Ontario

Thu 3/12

1:40 pm-3:13 pm

Nonstop1h 33m

$259

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 3/4

10:00 am-4:55 pm

2 stops6h 55m

Ontario

Tue 3/10

2:35 pm-10:05 pm

2 stops7h 30m

$269

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Mon 3/2

4:13 pm-5:41 pm

Nonstop1h 28m

Ontario

Mon 3/9

6:15 am-7:48 am

Nonstop1h 33m

$269

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 4/1

10:44 am-12:14 pm

Nonstop1h 30m

Ontario

Fri 4/3

1:27 pm-2:56 pm

Nonstop1h 29m

$274

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 4/29

9:09 pm-10:45 pm

Nonstop1h 36m

Ontario

Tue 5/5

6:00 am-7:29 am

Nonstop1h 29m

$275

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Tue 3/17

9:30 pm-10:57 pm

Nonstop1h 27m

Ontario

Tue 3/24

6:37 pm-8:10 pm

Nonstop1h 33m

$279

San FranciscoOntario

SFO - ONT

SFOONT

San Francisco

Wed 3/4

4:13 pm-5:41 pm

Nonstop1h 28m

Ontario

Wed 3/11

1:40 pm-3:13 pm

Nonstop1h 33m

$279

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/3

Showing 1-10 of 23 results
1
2
3

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 January 30, 2026.

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 36 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, February is the cheapest month in which you can book a flight from Fremont to Ontario (average of $19). Flying from Fremont to Ontario in September is currently the most expensive (average of $60). 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 February 3, 2026.

One of the essential ways to save on airfare from Fremont to Ontario is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the evening could potentially save you up to 26% on airfare.

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 January 31, 2026.

Travelers seeking maximum savings on their Fremont to Ontario flight should consider departing on Tuesday evenings when fares are most often at their lowest. Monday at noon 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 February 3, 2026.

The most flights from FR8 to ONT are scheduled on a Monday (6 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (2 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 February 3, 2026.
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
11,833 reviews

Food

7.1

Boarding

8.1

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

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
11,833 reviews
Alaska Airlines
8.0
Very good
11,833 reviews

Food

7.1

Boarding

8.1

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

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
Delta
7.9
Good
8,138 reviews
Alaska Airlines
8.0
Very good
11,833 reviews

Food

7.1

Boarding

8.1

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

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
9,236 reviews
Alaska Airlines
8.0
Very good
11,833 reviews

Food

7.1

Boarding

8.1

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

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
American Airlines
7.2
Good
11,218 reviews
Alaska Airlines
8.0
Very good
11,833 reviews

Food

7.1

Boarding

8.1

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

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
11,833 reviews

Food

7.1

Boarding

8.1

Entertainment

7.0

Crew

8.5

Comfort

7.8

Overall

8.0

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 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 3 inbound flights from Fremont per day. 6 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 46 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 $219, United Airlines can have you in Ontario from Fremont in 1h 28m. The distance from Fremont to Ontario is about 363 mi. Generally, flights for this route are nonstop.

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

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $28. Users have also found prices from $28 and $58 on United Airlines and Alaska Airlines, respectively.

  • 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: Air Canada (80%), Emirates (76%), United Airlines (70%).

  • What are the cheapest flights from Fremont to Ontario?

    While on average a flight from Fremont to Ontario is generally $216, our data shows the cheapest flight currently is $84. When looking at the most popular route, (San Francisco - Ontario), you can expect to pay $108 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, February is the cheapest month in which you can book a flight from Fremont to Ontario (average of $19). Flying from Fremont to Ontario in September is currently the most expensive (average of $60). 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 Fremont to Ontario

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

Top 6 airlines flying from Fremont to Ontario

Discover the top 6 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 February 3, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$27Average$126FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$59Average$216FlexibilityNo cancel feeOn-time69%
DeltaCheapest$97Average$215FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$107Average$264FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$113Average$276FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$186Average$206FlexibilityNo cancel feeOn-time71%

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.