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$49+ Cheap flights from San Jose to Ontario (SJC - 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 10/21. Fares are subject to change and may not be available on all flights or dates of travel.
SJC — ONT
Oct 19 — Oct 261
Sun 10/19
Sun 10/26
1 adult, Economy
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Cheapflights Tip: The best prices from San Jose to Ontario are usually found in January or August, booked 62 days in advance, depart on a Tuesday or Thursday and return on a Saturday

Cheap flight deals from San Jose to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from San Jose (SJC) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 19, 2025.

Round-trip from

$97
(Southwest)

One-way from

$49
(Southwest)

Popular in

December

Cheapest in

January

Average price

$259

Good round-trip deal

$179 or less

Good one-way deal

$178 or less
From San Jose to Ontario
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One-way flight from San Jose to Ontario
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Highest demand for flights based on searches. 2% potential increase in price ($6 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from San Jose to Ontario.
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Price to beat on a one-way flight from San Jose to Ontario.
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Find flight deals from San Jose to Ontario

Cheapest flights from San Jose to Ontario
Explore the most affordable flight options available from San Jose to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 19, 2025.

This Southwest deal was found by Cheapflights users on 9/17. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/2511:30 amSJC - ONT
Nonstop1h 15mSouthwest
Sat 10/253:50 pmONT - SJC
Nonstop1h 15mSouthwest
Deal found 9/17$97
This Southwest deal was found by Cheapflights users on 9/16. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/97:00 amSJC - ONT
Nonstop1h 15mSouthwest
Tue 10/141:30 pmONT - SJC
1 stop5h 30mSouthwest
Deal found 9/16$107
This Southwest deal was found by Cheapflights users on 9/17. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/108:45 amSJC - ONT
1 stop3h 25mSouthwest
Thu 12/118:40 amONT - SJC
1 stop5h 35mSouthwest
Deal found 9/17$117
This Southwest deal was found by Cheapflights users on 9/16. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/1612:15 pmSJC - ONT
2 stops9h 40mSouthwest
Thu 10/237:55 pmONT - SJC
Nonstop1h 15mSouthwest
Deal found 9/16$118
This Southwest deal was found by Cheapflights users on 9/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2112:00 pmSJC - ONT
2 stops8h 40mSouthwest
Thu 10/235:55 pmONT - SJC
1 stop5h 00mSouthwest
Deal found 9/18$122
This Southwest deal was found by Cheapflights users on 9/17. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/256:45 amSJC - ONT
2 stops5h 40mSouthwest
Tue 10/288:50 amONT - SJC
2 stops7h 10mSouthwest
Deal found 9/17$127
This Southwest deal was found by Cheapflights users on 9/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/237:00 amSJC - ONT
Nonstop1h 15mSouthwest
Sat 10/2511:25 amONT - SJC
Nonstop1h 15mSouthwest
Deal found 9/18$134
This CheapOair deal was found by Cheapflights users on 9/18. 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 9/2612:25 pmSJC - ONT
1 stop7h 29mFrontier
Sun 9/288:59 pmONT - SJC
1 stop14h 31mFrontier
Deal found 9/18$144
This Booking.com deal was found by Cheapflights users on 9/18. 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.
Mon 9/2212:30 pmSJC - ONT
1 stop7h 24mFrontier
Wed 9/248:59 pmONT - SJC
1 stop16h 15mFrontier
Deal found 9/18$156
This Booking.com deal was found by Cheapflights users on 9/18. 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.
Mon 10/276:43 pmSJC - ONT
1 stop3h 22mFrontier
Fri 10/316:00 amONT - SJC
1 stop11h 34mFrontier
Deal found 9/18$162

Cheapflights Fare Finder

 
Customize your flight search to find flights from San Jose 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 September 19, 2025.
Use the filters below to find and compare flights from San Jose to Ontario that are best for you.

Fly from

San Jose

Fly to

Ontario

Route

Depart

Return

Price

San JoseOntario

SJC - ONT

SJCONT

San Jose

Wed 12/10

6:45 pm-8:00 pm

Nonstop1h 15m

Ontario

Thu 12/11

11:10 am-12:25 pm

Nonstop1h 15m

$97

San JoseOntario

SJC - ONT

SJCONT

San Jose

Sat 11/1

3:35 pm-4:50 pm

Nonstop1h 15m

Ontario

Mon 11/3

6:50 pm-8:05 pm

Nonstop1h 15m

$134

San JoseOntario

SJC - ONT

SJCONT

San Jose

Sun 9/28

12:26 pm-7:59 pm

1 stop7h 33m

Ontario

Sun 9/28

10:28 pm-5:45 pm

1 stop19h 17m

$156

San JoseOntario

SJC - ONT

SJCONT

San Jose

Fri 10/17

12:27 pm-11:50 pm

1 stop11h 23m

Ontario

Sun 10/19

10:47 pm-5:48 pm

1 stop19h 01m

$156

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 10/23

7:00 am-8:15 am

Nonstop1h 15m

Ontario

Sun 10/26

7:00 am-8:15 am

Nonstop1h 15m

$188

San JoseOntario

SJC - ONT

SJCONT

San Jose

Sat 12/6

7:05 am-8:20 am

Nonstop1h 15m

Ontario

Sun 12/7

10:35 am-11:50 am

Nonstop1h 15m

$188

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 10/16

7:00 am-8:15 am

Nonstop1h 15m

Ontario

Thu 10/23

5:55 pm-10:55 pm

1 stop5h 00m

$188

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 10/30

7:00 am-8:15 am

Nonstop1h 15m

Ontario

Sun 11/2

5:25 am-6:40 am

Nonstop1h 15m

$188

San JoseOntario

SJC - ONT

SJCONT

San Jose

Thu 12/4

10:35 am-11:55 am

Nonstop1h 20m

$49

San JoseOntario

SJC - ONT

SJCONT

San Jose

Wed 12/10

7:00 am-12:10 pm

1 stop5h 10m

$59

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/18

Showing 1-10 of 20 results
1
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The best insider tips for San Jose to Ontario flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your San Jose to Ontario trip
Airports
SJC

SJC offers free Wi-Fi throughout the airport, making it easy to stay connected while waiting for your flight.

Read more about SJCby Daniel Scheffler
ONT

Consider renting a car at ONT for quick access to I-10, ideal for exploring Southern California.

Read more about ONTby Bill Fink
Our travel experts
Bill Fink

Bill Fink

Expert on ONT

Bill Fink

Bill Fink

Bill is an award-winning travel writer with extensive credits covering airlines and the aviation industry for publications including AARP, AFAR, The Points Guy and Yahoo. Based in Portland, Oregon, Bill has traveled to more than 75 countries - and been late for his flight in most of them. He once achieved top-level frequent flier status for all of American, Delta and United Airlines during a single year.

Read more
Daniel Scheffler

Daniel Scheffler

Expert on SJC

Daniel Scheffler

Daniel Scheffler

Daniel Scheffler is a travel writer, podcaster, and producer. Born in Africa, bred in Europe and now living in America he has traveled to 140 countries (and all 50 U.S. states). Plus he has stayed at over 2500 hotels across the globe. His original shows Everywhere and Without Maps (available on Spotify) showcase his beliefs, travel is about humanity and sharing that beauty. And thus it reminds you that you shouldn’t believe everything you think.

Read more

Best time to book a flight from San Jose to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from San Jose 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 San Jose to Ontario

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

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

To ensure you get the cheapest price possible for a flight from San Jose to Ontario, you should look to book at least 61 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, August is the cheapest month in which you can book a flight from San Jose to Ontario (average of $246). Flying from San Jose to Ontario in March is currently the most expensive (average of $327). 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 SJC to ONT?

Find hourly flight availability from San Jose 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 September 19, 2025.

It’s optimal to fly from San Jose to Ontario at noon. By choosing this option you can save up to 19% on the cost of your flight, compared to a flight in the afternoon.

What is the cheapest day to fly from San Jose to Ontario?

Use this chart to determine the cheapest time to fly round-trip from San Jose to Ontario. Price data was last updated on September 14, 2025.

Travelers seeking maximum savings on their San Jose to Ontario flight should consider departing on Saturday afternoons when fares are most often at their lowest. Monday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

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 September 19, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest, and Frontier from San Jose to Ontario 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

Food

7.1

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Crew

8.5

Overall

8.0

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

Food

7.1

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Crew

8.5

Overall

8.0

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

Food

7.1

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Crew

8.5

Overall

8.0

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

Food

7.1

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Crew

8.5

Overall

8.0

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 San Jose to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airports do I use to fly from San Jose to Ontario?

    To fly from San Jose to Ontario, you need to book a flight from San Jose (SJC) to Ontario (ONT). Nonstop flights to Ontario from San Jose take 1h 15m on average. When it comes time to book airfare, you have a few options: there are 2 outbound flights from San Jose to Ontario offered by 3 different airlines.

  • How popular is this San Jose to Ontario flight route?

    Within the past month, 5 users have taken a look at flights from San Jose to Ontario.

  • How long is the flight from San Jose to Ontario?

    A quick flight from San Jose to Ontario can take about 1h 15m. Southwest provides one of the quickest options available for as low as $97. The distance between San Jose and Ontario is about 333 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines flying from San Jose to Ontario round-trip?

    According to our current data, Frontier ($44), Southwest ($134), and Alaska Airlines ($196) offers the cheapest pricing from San Jose to Ontario. Frontier is 83% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest flights from San Jose to Ontario?

    Looking at all options, your cheapest flight can be booked for $38. While the most popular route (San Jose - Ontario) can be booked for $97 on average, our data indicates $278 when flying from San Jose to Ontario.

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

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

  • How can I find direct flights from San Jose to Ontario?

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

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

    Yes. Cheapflights offers flight deals from San Jose 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 San Jose to Ontario?

    Currently, August is the cheapest month in which you can book a flight from San Jose to Ontario (average of $246). Flying from San Jose to Ontario in March is currently the most expensive (average of $327). 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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Alternative routes for San Jose to Ontario

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Top 3 airlines flying from San Jose to Ontario

Discover the top 3 airlines that operate flights from San Jose 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 September 19, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$44Average$129FlexibilityNo cancel feeOn-time62%
SouthwestCheapest$134Average$277FlexibilityNo cancel feeOn-time63%
Alaska AirlinesCheapest$196Average$262FlexibilityNo cancel feeOn-time75%

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