$178 Cheap Flights from San Juan (SJU) to Ontario (ONT)

View $178 flight on Tue, Oct 14, 2025Opens in a new window

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Find available prices by choosing your travel dates.

Cheap Flights from San Juan to Ontario (SJU-ONT)

Prices were available within the past 7 days and start at $178 for one-way flights and $355 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Wed, Sep 24 - Mon, Sep 29
SJU
San Juan
ONT
Ontario
$355 Roundtrip, just found
$355
Roundtrip
just found
Select United flight, departing Wed, Sep 24 from San Juan to Ontario, returning Mon, Sep 29, priced at $355 just found
Delta
Sat, Sep 13 - Thu, Sep 18
SJU
San Juan
ONT
Ontario
$358 Roundtrip, found 1 day ago
$358
Roundtrip
found 1 day ago
Select Delta flight, departing Sat, Sep 13 from San Juan to Ontario, returning Thu, Sep 18, priced at $358 found 1 day ago
United
Wed, Jul 30 - Tue, Aug 5
SJU
San Juan
ONT
Ontario
$361 Roundtrip, found 4 hours ago
$361
Roundtrip
found 4 hours ago
Select United flight, departing Wed, Jul 30 from San Juan to Ontario, returning Tue, Aug 5, priced at $361 found 4 hours ago
United
Wed, Sep 24 - Mon, Sep 29
SJU
San Juan
ONT
Ontario
$366 Roundtrip, just found
$366
Roundtrip
just found
Select United flight, departing Wed, Sep 24 from San Juan to Ontario, returning Mon, Sep 29, priced at $366 just found
United
Thu, Aug 7 - Mon, Aug 11
SJU
San Juan
ONT
Ontario
$375 Roundtrip, found 5 hours ago
$375
Roundtrip
found 5 hours ago
Select United flight, departing Thu, Aug 7 from San Juan to Ontario, returning Mon, Aug 11, priced at $375 found 5 hours ago
United
Fri, Aug 8 - Sun, Aug 17
SJU
San Juan
ONT
Ontario
$382 Roundtrip, found 2 days ago
$382
Roundtrip
found 2 days ago
Select United flight, departing Fri, Aug 8 from San Juan to Ontario, returning Sun, Aug 17, priced at $382 found 2 days ago
American Airlines
Tue, Oct 7 - Sun, Oct 12
SJU
San Juan
ONT
Ontario
$397 Roundtrip, found 10 hours ago
$397
Roundtrip
found 10 hours ago
Select American Airlines flight, departing Tue, Oct 7 from San Juan to Ontario, returning Sun, Oct 12, priced at $397 found 10 hours ago
Southwest Airlines
Tue, Oct 7 - Sun, Oct 12
SJU
San Juan
ONT
Ontario
$400 Roundtrip, found 10 hours ago
$400
Roundtrip
found 10 hours ago
Select Southwest Airlines flight, departing Tue, Oct 7 from San Juan to Ontario, returning Sun, Oct 12, priced at $400 found 10 hours ago
United
Tue, Oct 7 - Sun, Oct 12
SJU
San Juan
ONT
Ontario
$403 Roundtrip, found 10 hours ago
$403
Roundtrip
found 10 hours ago
Select United flight, departing Tue, Oct 7 from San Juan to Ontario, returning Sun, Oct 12, priced at $403 found 10 hours ago
JetBlue Airways
Wed, Jun 11 - Fri, Jun 13
SJU
San Juan
ONT
Ontario
$412 Roundtrip, found 14 hours ago
$412
Roundtrip
found 14 hours ago
Select JetBlue Airways flight, departing Wed, Jun 11 from San Juan to Ontario, returning Fri, Jun 13, priced at $412 found 14 hours ago
Flights from San Juan (SJU) to Ontario (ONT)
Origin airport
Luis Munoz Marin Intl.
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, JetBlue Airways, Southwest Airlines, United
Roundtrip price
$349
Distance
3335 mi

San Juan to Ontario Flights

The cheapest times to fly from San Juan to Ontario

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from San Juan to Ontario are during the month of September. You can find some of the cheapest flights from San Juan to Ontario with Expedia's search tool and vast selection of airlines.

The best time to book a flight from San Juan to Ontario

Sunday is one of the best days to book for cheap flights from San Juan to Ontario: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

How to find cheap round-trip tickets from San Juan to Ontario

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from San Juan to Ontario in 2025. You can also book with separate airlines for your outbound and return journeys, from $178 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap San Juan to Ontario flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

You could also save big by booking one of Expedia's vacation packages. Bundling together your San Juan to Ontario airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

*Terms apply.

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

Frequently asked questions

How much does a flight from Luis Munoz Marin Intl. Airport (SJU) to Los Angeles - Ontario Intl. Airport (ONT) cost?
Discover the latest flight deals from SJU to ONT by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from SJU to ONT?
The cheapest flights from SJU to ONT are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from SJU to ONT?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from SJU to ONT. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from Luis Munoz Marin Intl. Airport (SJU) to Los Angeles - Ontario Intl. Airport (ONT)?
You’ll have to book a flight with a layover when traveling from Luis Munoz Marin Intl. Airport (SJU) to Los Angeles - Ontario Intl. Airport (ONT). Direct flights don’t operate daily on this route. However, simply filter your search to include one or two stops to find the best option for your trip.
What day of the week has the most flights from SJU to ONT?
You’ll usually find Tuesday the quietest day for flights, while Fridays tend to be the busiest.* However this can vary from season to season and during public holidays or peak travel times.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Luis Munoz Marin Intl. Airport (SJU) to Los Angeles - Ontario Intl. Airport (ONT)?
To avoid potential delays on the Luis Munoz Marin Intl. Airport (SJU) to Los Angeles - Ontario Intl. Airport (ONT) route, aim to travel before 3 PM. Departures after this time have a 22% higher chance of cancellation.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.
Is it cheaper to buy a plane ticket from Luis Munoz Marin Intl. Airport (SJU) to Los Angeles - Ontario Intl. Airport (ONT) last-minute?
Booking your flight from SJU to ONT just before your getaway is typically more expensive. But if you’re flexible with your travel times and dates, you could bag a cheap last-minute fare.
Is it cheaper to book a SJU to ONT flight and hotel package?
Securing a SJU to ONT flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your trip in one place. Pick from our extensive range of hotels and then add flights, activities and car rentals to your booking. Bundle it all together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Luis Munoz Marin Intl. Airport (SJU) to Los Angeles - Ontario Intl. Airport (ONT)?
If you booked your SJU to ONT flight within the last 24 hours, you may be able to modify or cancel it at no cost. Depending on the airline and the type of fare you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, go to our Customer Service portal if you want more information.

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*Available to One Key members.