ONT - SJU

$178 Find Cheap Flights from Ontario to San Juan

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ontario to San Juan departing on 11/3. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to San Juan Luis Munoz Marin Intl Airport

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to San Juan, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to San Juan, as well as popular online travel agencies
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Flight Deals

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

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Ontario to San Juan that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Ontario to San Juan

Wed, Oct 22 - Wed, Oct 29
United Airlines Logo
6:00 am - 8:38 pmONT-SJU
11h 38m1 stop
United Airlines Logo
7:10 am - 8:44 pmSJU-ONT
16h 34m2 stops
$355United Airlines
Find Deal
Wed, Oct 22 - Sat, Oct 25
Frontier Logo
6:53 am - 2:30 amONT-SJU
16h 37m2 stops
Frontier Logo
4:22 pm - 7:49 amSJU-ONT
18h 27m2 stops
$357Frontier
Find Deal
Thu, Nov 13 - Wed, Nov 19
Multiple Airlines Logo
11:59 am - 7:39 pmONT-SJU
27h 40m1 stop
Multiple Airlines Logo
9:00 am - 9:27 pmSJU-ONT
16h 27m2 stops
$372Multiple Airlines
Find Deal
Thu, Dec 4 - Tue, Dec 9
United Airlines Logo
5:05 am - 10:22 pmONT-SJU
13h 17m2 stops
United Airlines Logo
7:45 am - 5:37 pmSJU-ONT
13h 52m2 stops
$373United Airlines
Find Deal
Thu, Dec 4 - Mon, Dec 8
Multiple Airlines Logo
6:50 pm - 4:39 amONT-SJU
29h 49m1 stop
Multiple Airlines Logo
3:55 am - 9:04 pmSJU-ONT
21h 09m2 stops
$376Multiple Airlines
Find Deal
Thu, Dec 4 - Tue, Dec 9
United Airlines Logo
5:05 am - 10:22 pmONT-SJU
13h 17m2 stops
United Airlines Logo
7:45 am - 5:37 pmSJU-ONT
13h 52m2 stops
$379United Airlines
Find Deal
Tue, Oct 21 - Tue, Oct 28
American Airlines Logo
10:29 pm - 3:55 pmONT-SJU
14h 26m1 stop
American Airlines Logo
5:30 am - 3:24 pmSJU-ONT
12h 54m2 stops
$406American Airlines
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Sun, Oct 19 - Wed, Oct 22
JetBlue Logo
10:56 pm - 12:58 pmONT-SJU
11h 02m1 stop
JetBlue Logo
1:25 pm - 9:29 pmSJU-ONT
11h 04m1 stop
$426JetBlue
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Mon, Nov 17 - Tue, Dec 2
American Airlines Logo
12:55 pm - 1:43 pmONT-SJU
20h 48m2 stops
American Airlines Logo
2:50 pm - 12:00 pmSJU-ONT
25h 10m2 stops
$461American Airlines
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Fri, Oct 17 - Thu, Oct 23
Delta Logo
10:00 pm - 11:36 amONT-SJU
10h 36m1 stop
Delta Logo
12:46 pm - 10:22 pmSJU-ONT
12h 36m1 stop
$471Delta
Find Deal

Everything you should know

Top airlines
United Airlines
Cheapest • from $355 (round-trip)
Southwest
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
4 weeks
in advance
Our data shows that travelers who book at least 4 weeks in advance save around 25% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
April
Cheapest • 20% price drop
August
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Cheapest round-trip
$355
Overall average: $509
United Airlines
Wed 10/22Wed 10/29
ONT - SJU • 1 stop
Cheapest one-way
$178
Typical prices: $333-414
American Airlines
Mon 11/3
ONT - SJU • 2 stops
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to San Juan!
Booking Insights

KAYAK's insights & trends for Ontario to San Juan flights

Get data-powered insights and trends into flights from Ontario to San Juan to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from Ontario to San Juan?

The average price of all round-trip flights from Ontario to San Juan Luis Munoz Marin Intl Airport clicked on KAYAK for each day over the last 12 months.

If your flying dates are flexible, you should consider flying to San Juan on a Tuesday, as we generally find the cheapest rates on that day for this route. On the other hand, Thursday is the most expensive day to fly from Ontario to San Juan. For your return ticket, we recommend flying on a Wednesday and avoiding Mondays for the best deals.

What is the cheapest month to fly from Ontario to San Juan Luis Munoz Marin Intl Airport?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to San Juan Luis Munoz Marin Intl Airport, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Ontario to San Juan Luis Munoz Marin Intl Airport is April, where tickets cost $484 (return) on average. On the other hand, the most expensive months are December and March, where the average cost of round-trip tickets is $788 and $694 respectively.

How far in advance should I book a flight from Ontario to San Juan Luis Munoz Marin Intl Airport?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Ontario to San Juan Luis Munoz Marin Intl Airport, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Ontario to San Juan Luis Munoz Marin Intl Airport, you should book around 4 weeks before departure, which saves you about 25% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 21 weeks before departure.

Good to know

Low seasonOctober
Cheapest flight$178
Best time to beat the crowds with an average 16% drop in price.
Most popular time to fly and prices are also 6% lower on average.
Flight from Ontario to San Juan

When to book flights from Ontario to San Juan

Are your dates flexible? Find out the best times to travel from Ontario to San Juan based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking Ontario to San Juan flights

  • What is the cheapest flight from Ontario to San Juan Luis Munoz Marin Intl Airport?

    In the last 3 days, the lowest price for a flight from Ontario to San Juan Luis Munoz Marin Intl Airport was $178 for a one-way ticket and $355 for a round-trip.

  • Do I need a passport to fly between Ontario and San Juan?

    A passport is required to fly from Ontario to San Juan.

  • Which aircraft models fly most regularly from Ontario to San Juan?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Ontario to San Juan?

    SkyTeam, Star Alliance, and oneworld are the airline alliances operating flights between Ontario and San Juan, with SkyTeam being the most commonly used for this route.

  • Which is the best airline for flights from Ontario to San Juan, Southwest or Delta?

    The two airlines most popular with KAYAK users for flights from Ontario to San Juan are Southwest and Delta. With an average price for the route of $598 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $534 and an overall rating of 7.9.

  • How does KAYAK find such low prices on flights from Ontario to San Juan?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ontario to San Juan.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ontario to San Juan?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to San Juan from Ontario is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Ontario to San Juan?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to San Juan with an airline and back to Ontario with another airline. Booking your flights between Ontario and SJU can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ontario to San Juan?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to San Juan from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 5 airlines serving from Ontario to San Juan

 
See real verified KAYAK customer reviews for airlines flying from Ontario to San Juan. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Ontario to San Juan? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4248 reviews
8.6Crew
8.1Boarding
7.5Entertainment
8.0Comfort
7.0Food
Airline reviews

As always, the entire Southwest experience was wonderful, from online booking to flight to baggage retrieval. Very grateful.

10.0 ExcellentRobert, Sep 2025SFO - LAS
Read more Southwest reviews

As always, the entire Southwest experience was wonderful, from online booking to flight to baggage retrieval. Very grateful.

The weather could have been better. There was a 40 minute ATC delay in SFO because of marine fog and a micro cell storm delayed landing and take-off at Nashville. The gate was changed 5 minutes from boarding from gate B3 to gate C23 at Nashville airport.

The cabin was quiet for the redeye flight. The area was clean. The staff was great. The 787 Max was in good condition. Drawbacks were that the seat widths were tight for some passengers. The seat padding was at best average and for a long flight uncomfortable.

Delayed flight. Nicest crew member was a SW pilot flying seated next to me who kindly move to seat the final passenger. Flight extra delayed. My cup of refreshment of ginger ale was so packed with ice it was literally 2 sips.

No trays in our seats, we sat in first row, purchased a business class fare. Had to hold our drinks and snack in our hands. No plugs for our cell phones. Had to pay for it a drink cocktail each. Seats so uncomfortable.

Flight wasn’t even full, but too many carry-ons caused us to run out of bin space. New bag fee has folks who would usually check their bags carrying on. Watching Southwest morph into Spirit/Frontier is so sad to watch

Southwest is Southwest. No frills. If you're luck enough to get a happy crew (we did), then it makes for a nicer flight.

It was a perfect flight in all aspects! Both legs!

Great flight, 47 passengers on a 180 seat plane. Stewardess was pleasant and cheerful.

I liked the crew member who gave flight instructions on "in case of a problem:. The seats are so small that only a young teenager could sit in middle seat.

Flight delayed for two and half hours and then canceled altogether due to mechanical issues. No mechanic onsite to fix so had to send one from LAX.

My husband upgraded our seats and I don't know if it was due to the type of planet was or if they didn't upgrade our seats. We were supposed to be in I believe comfort seats and they were just as tight as any other seat- no leg room and we are very tall people but at least it wasn't extremely cold. My husband did put in a complaint about our seating because he paid extra and if we would have known that the space and the tightness would have been the same, we just would have gotten the emergency row emergency row seats that we normally get. We love Delta but both our flights coming home we're not good. Oh I forgot to mention that on our flight to Hawaii our luggage wheels got broke and we had to purse new luggage on vacation then we never had this problem so we didn't know protocol and reported it after we got home only for them to tell is we only had 24hrs to report the damage. Not sure what was going on with Delta this vacation trip.

Crew was excellent. Comfort seats not as nice as other kinds of planes.

It was a great flight and the stewards and stewardess were all kind and accommodating!! The seats were comfortable and entertainment screen excellent!

There are 4 flights in consecutive gates with about the same departure time. Two flights were boarding at the same time. One was delayed or boarding would be happening at the same time. I am not sure what Delta and LAX need to do to have a better layout at the end of Terminal 2

There was a security issue at the airport and we were unable to land. We circled endlessly and then landed at another airfield for fuel. We then circled the airport again, almost landed but didn’t fully touch down before circling again. I am thankful to the crew for keeping us safe- the issue was the airline and staff at the airport getting us seats on our connecting flights. That part was hours of searching for someone and getting in double my steps.

Most aspects were good however if they assign boarding zones they ought to enforce them or why bother? My luggage from SAN-JFK-MAD was lost in NY so I without my main bag for two days upon arrival in Spain. They were helpful in tracking it and eventually delivered it to my hotel. The flub was because of a delay upon arrival in NYC. I had booked 2 1/2 hours between flights but we had to hold on the taxiway for an hour after landing while waiting for a clear gate which likely caused the baggage error.

Excellent flight, the planes were newer, they did a nice job with boarding, great service overall.

It would be nice if was given wires ear buds. Overall was a good experience was able to sleep on the plane

737-800 in first class was pretty dumpy. Seat had an uncomfortable angle, storage under the seat was blocked so even my very modest backpack didn't fit, power outlet was flaky. Weird tiny seat pockets that couldn't hold a gallon ziploc bag, emesis bag missing, etc. etc. No in-flight service due to turbulence. Crew was excellent, boarding was smooth despite a full flight.

I was in first class. The outlets at my seat did not work. The plane was shabby and run down. I had prepurchsed a day subscription for internet that was not redeemable. I had to repurchase the internet for my flight and then it didn’t work anyway. Quite disappointed in what was supposed to be the launch of a great vacation.

We had to deboard 2 times due to maintenance issues. They changed the plane, and then we got deviated to LAX due to maibtenance issues on the other plane, had to sleep at LAX and los a full day.

From the first moment you interact with United Airlines, you can expect nothing less but extreme frustration. The baggage handler at the bag drop seems completely unbothered by the presence of customers waiting in line. No help was extended to load the baggage whatsoever. And if any of your bags is overweight by 0.01 pound they will make you re-distribute everything in your suitcase just to play power trip. When it was time to board no help was extended to customers to locate their seats. Moreover. It was a chaotic mess at the gate when it was unclear who should board first and everyone just bunched up, trying to get on the plane. I am sure the crew was doing their best to perform their jobs while being paid their wages however it shouldn’t be that hard to smile once or twice when you’re in the business if serving customers. It is a shame for the United States of America to have a flagship carrier of such low caliber. Our flight was also delayed by about an hour and a half due to further delays prior to our inbound flight. Being someone who has travelled for both business and leisure in Asia, Europe, and South America I have never experienced such poor quality of service.

I understand stuff happens, but plane failures are likely due to lack of maintenance. Additionally, air conditioning wasn't working, no snack/drink service, no WiFi. Fortunately, the crew was communicative and light-hearted. United grabbed another plane and we were able to get to our destination.

The pilots were late and it made us 1 hour late. The meat was tough and bok choy was also tough.

Stuck on tarmac for two hours plus a 5.5 hour flight. Rude flight attendant. And no meals, not even for purchase!

I learned that seating towards the end of plane that a line forms for the restroom and people use your chair as a hand railing, bumping your seat consistently. I was seated in the aisle. I think that next time if I am towards the back row I would want to sit in the middle or window seat.

The best airline I have ever travel , really good customer service, attention and service !!

United sent me a mileage plus number last year but that number is invalid so I can’t use it to check into flights or collect mileage. There is human to speak about the problem, only computers who keep asking me if I am using the correct email. It’s so frustrating and I cannot resolve it.

Not a great experience. We paid for the upgrade for premium economy seats and seated ourselves in very comfortable seats. Someone came along with the same seat on their boarding pass. The aircraft had been changed and as a result we were booted out and sent further back to small uncomfortable seats. After complaining we were moved to emergency row seats, which gave us more leg room but the seats don’t recline. For people in our 70’s we found having to sit upright from California to NJ very uncomfortable. Not sure why they chose to move senior citizens instead of the two people that were allowed to take the more comfortable seats. Not happy.

It was a red eye flight, so no meals were provided, but it was fine with snacks. The seats felt cramped and almost too narrow.

Very crowded flight but what can you expect these days?? Crew was accommodating.

The seats in economy were appeared to be quite thin and lack sufficient cushioning to be comfortable. Perhaps it was my seating position but the plane seemed notably load.

The entertainment package was vast and the selections were very current. Keep updating it was great.

The seat was so hard my tailbone was aching The crew was kind of a b**** because I made a joke that I didn't care if they close the door I total c*** when she was trying to f****** act like she was mad at me because I said that The flight was bumpy. Sure you didnt have control over that.

4 hours late, including over +1 hour waiting in plane to take off. Baggage left behind too.

While waiting to claim my checked luggage, I discovered the airline had lost it. After a long wait and inquiries, I discovered it was on another flight. Fortunately, the airline finally sent my luggage home.

Was not able to watch most shows on the entertainment site. They would not load

Our flight was 1.5 hours delayed. There was no weather for the inbound flight, so I don't understand why. This meant a VERY late arrival and only a quick nap before my morning flight.

The plane was broken so we had to change planes.

This airline sucks. They offer low rates then charge you for everything, the app does not work well, the seats are the most uncomfortable. Maintenance issues on the flight, and you still have to sit through their credit card commercials. People are nice enough but does not make up for overall poor experience.

The worst. They don’t follow procedure for boarding per group. Flight got delayed for no understandably reasons, they changed our destination from PR to Miami, left us inside a plane for more than 8 hours, then cancelled flight in Miami leaving us stranded. Poorly managed re-accommodation for a new flight and overnight stay so I have to spend in a new ticket and my own hotel room to been able to get to my office next day. Lost 2 days of work and as a doctor, patients loosing their appointments. to other flights and besides

Cancelled flight after I arrived at airport after 75 min drive and parking. Next flight was 4 days in the future. Had to scramble and buy a much more expensive flight on another carrier.

I liked the turn-style feature at gate 209B at LAX. Very efficient process. The gate staff also made several, clearly directed announcements so I felt very informed.

I liked the price of the flight and the chance to buy a seat with no person seated in the middle seat.. Also the flight was right on time.

The seats were awful, hard plastic covered in sheet vinyl. The airline tries to scam you into paying extra to get seat together when the flight wasn’t full. They were going to separate a family with young children but my wife who had a row to herself gave up her seat so the young mom could be with her young boys. I’m never giving this airline my money again.

It was a short flight so no food or entertainment….

Frontier had yet another flight cancellation. Have never made a complete round trip with this airline without at least one leg getting cancelled. Miserable flights - dirty, uncomfortable planes that apparently always have issues since I've had multiple delays and cancellations with them.

Flight was delayed 3 times, would have been nice to have received text message instead of email notifications. Frontier app wasn’t even updated accordingly, no gate number disclosed. No agent at front desk of gate to inform of delay. Very confused and left if the dark

They changed the timing , first delayed by 4 hours then went back to 40 mins late, we had to run back to airport to not miss our flight. This is ridiculous

Everything you need to know for your flight from Ontario to San Juan

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