ONT - SJU

$147 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 4/20. 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, 0 bags

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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Everything you should know

Cheapest round-trip
$294
Overall average: $475
American Airlines
Fri 4/24Fri 5/1
ONT - SJU • 1 stop
Cheapest one-way
$157
Typical prices: $223-$343
Frontier
Mon 4/20
ONT - SJU • 2 stops
Top airlines
American Airlines
Cheapest • from $294 (round-trip)
Southwest
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
3 weeks
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 20% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 31% price drop
March
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to San Juan!
Flight Deals
Booking Insights
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

Fri, Apr 24 - Fri, May 1
American Airlines Logo
10:26 pm - 8:51 pm
ONT
-
SJU
19h 25m
1 stop
American Airlines Logo
11:59 pm - 11:34 am
SJU
-
ONT
14h 35m
2 stops
$294American Airlines
Tue, May 5 - Tue, May 12
United Airlines Logo
6:00 am - 9:24 pm
ONT
-
SJU
12h 24m
2 stops
United Airlines Logo
7:20 am - 8:36 pm
SJU
-
ONT
16h 16m
2 stops
$320United Airlines
Sat, May 9 - Thu, May 14
Delta Logo
11:04 pm - 11:46 am
ONT
-
SJU
9h 42m
1 stop
Delta Logo
12:50 pm - 9:54 pm
SJU
-
ONT
12h 04m
1 stop
$346Delta
Sun, Mar 1 - Thu, Mar 5
American Airlines Logo
5:02 pm - 10:00 am
ONT
-
SJU
12h 58m
2 stops
American Airlines Logo
8:40 am - 9:24 pm
SJU
-
ONT
16h 44m
1 stop
$352American Airlines
Sat, Apr 11 - Mon, Apr 20
Multiple Airlines Logo
7:40 pm - 11:07 am
ONT
-
SJU
12h 27m
1 stop
Multiple Airlines Logo
10:55 am - 11:55 pm
SJU
-
ONT
40h 00m
2 stops
$363Multiple Airlines
Mon, May 4 - Mon, May 18
Southwest Logo
8:45 pm - 10:35 am
ONT
-
SJU
10h 50m
2 stops
Southwest Logo
5:05 am - 3:15 pm
SJU
-
ONT
13h 10m
2 stops
$368Southwest
Sat, May 9 - Tue, May 12
American Airlines Logo
10:26 pm - 10:48 am
ONT
-
SJU
9h 22m
1 stop
American Airlines Logo
7:00 pm - 10:09 am
SJU
-
ONT
18h 09m
2 stops
$376American Airlines
Sat, May 9 - Wed, May 13
Delta Logo
11:04 pm - 11:46 am
ONT
-
SJU
9h 42m
1 stop
Delta Logo
12:50 pm - 9:54 pm
SJU
-
ONT
12h 04m
1 stop
$377Delta
Tue, May 12 - Wed, May 13
United Airlines Logo
6:00 am - 8:38 pm
ONT
-
SJU
11h 38m
1 stop
United Airlines Logo
7:20 am - 10:30 pm
SJU
-
ONT
18h 10m
2 stops
$379United Airlines
Wed, May 6 - Mon, May 11
Multiple Airlines Logo
7:29 pm - 5:30 pm
ONT
-
SJU
19h 01m
2 stops
Multiple Airlines Logo
6:49 pm - 8:39 pm
SJU
-
ONT
28h 50m
1 stop
$380Multiple Airlines
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 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 October, where tickets cost $391 (return) on average. On the other hand, the most expensive months are December and June, where the average cost of round-trip tickets is $812 and $643 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 3 weeks before departure, which saves you about 20% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 26 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$157
Best time to beat the crowds with an average 7% drop in price.
Most popular time to fly with an average 3% increase in price.
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 $147 for a one-way ticket and $294 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, oneworld, and Star Alliance 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 $586 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 $530 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 4283 reviews
7.5Entertainment
8.0Comfort
7.0Food
8.1Boarding
8.6Crew
Airline reviews

The seats are now more narrow. I paid for front row the seats in the front are even more narrow than before.

2.0 MediocreDavid, Feb 2026
SAN - LAS
Read more Southwest reviews

The seats are now more narrow. I paid for front row the seats in the front are even more narrow than before.

The wifi on the plane is great. The only issue that I have is that I prefer an aisle seat and on my trips this week, I was either in the middle or window. If we can work to secure aisle seating, I will be thrilled. Nice trip.

Great flight but super high price. Glad it was a business trip and not personal

3 hour delay. Had to change plans and was still delayed.

We got exit row seats both flights. Everything was running on time

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.

Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight

Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.

The plane was an older model, so it wasn’t as comfortable as others. The flight attendants were not helpful during onboarding. It was a full flight so there was chaos finding space for baggage.

Awesome! On time flight, early arrival, and a complimentary upgrade!

It was nt delta. It was aeromexo. Service was awful. They served a very small drink and NO snack for a 3hr and 35min flight. Then for the first 30 min of the flight is was talk and talk over head interruption the movie/ show i picked to watch.

Delta One is extraordinary. I fly business when somebody hires me. I just wonder why there is such a chasm between business class and the insanely inhumane and nonsensical coach. The seats are not large enough to fit even my tiny wife. We fly 10% of what we did because we don’t want to pay 5-10 k but for $400 it’s unbearable. It seems like the accountants took over and made stupid decisions. Screw in 20 extra seats and make it so unbearable that people fly 90% less. Just put the damn price up and put some proper chairs in. But business, yay.

Delta’s staff is unmatched. From the gate agents, to the pilots, to the flight attendants… all top of the industry.

The flight was delayed for about 2 hrs. Other than it, it was good.

I am extremely disappointed that delta internal pilot manuals now refer to the Gulf of Mexico as the “gulf of America”. You can bow down to the Orange turd on your own. I will never fly delta again

No lunch on a x-country flight scheduled for 10:50 am departure, arrived 5+ hrs later. That requires a black box label before you pay for the tickets. Worst, when I checked in online, it's specifically said that lunch was served on his flight for economy Plus passengers.

Our flight from SFO to MSP was right on time on 11/15/2025. No delays. As we approached MSP at about 8 pm, we circled in the air until 8:40 pm so I don't call that efficient for MSP. I think the captain should announce the delay and why. (as if we all don't know that we are just circling around the area, slowing down, speeding up, slowing down.) Thank you. Marilyn Fischer

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

Crew was great (professional, attentive, prompt). Snacks for 4 hrs flight is deplorable.

Flight delayed. WiFi connectivity very poor if not existant. Last minute arrival forced me to run to catch my connection.

Terrible. No customer service, no food, no drinks on a 6 hour premier economy booking.

Check-in and in-flight staff were better than average. The seat was a fair size but too hard and not enough padding. The cushion/pillow provided is poor (thin and seems to be disposable ,it provides no effective cushioning or support). Food was OK-ish but no choice of inflight snacks and no easy place to get drinks other than water (I could ask for juice by intruding into the staff area at the back of the plane) Entertainment was very good actually. Overall better than I expected from a US-based airline (sorry!) but compared to ANA or Singapore it was so-so. (I live in Japan so they are my comparative airlines)

Terrible. Our first time back on United for 10 years, the seats in Polaris class are small and uncomfortable. They have squished too many people in to get more $$$. The staff are not friendly and not wanting to accommodate. I asked for two salads rather than a main meal and was advised no we wont do that. Then asked what I would like for breakfast and given something else anyway. I will not be flying United International anytime soon.

The food was terrible this time. Otherwise pleasant, quiet, on-time.

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

The flight crew where really good. Better then the crew from BNE to SFO

Food should be changed in menu Many muslims travels in this airlime they need to add one Halal meal

left on time, reasonable boarding process arrived early luggage came out quickly

Flight was delayed for 2 hours, then last minute the change to on time. The satélite location is far and a nightmare to get to.

We flew in first class. The crew did not offer drinks before the flight took off, but they treated us well during the flight. The food was excellent. There was actually too much food served, but it was nice to have all the options.

For a 5 1/2 hour flite i considered the "business class" to be subpar. The seats were just ok, no amenities, really nothing more than a long domestic flight. Frankly disappointed.

It would be nice to have some low carb options in the snacks.

The entertainment options were at best, fair. It was exactly the same as my outbound flight. It would have been more entertaining if there were some series from Apple TV, HBO, Showtime or other carriers for me to catch up with.

The flight was on time and arrived early. The crew were friendly and helpful.

While I didn’t watch much tv I would have liked a few more options of TV series from Apple TV or hbo max ..

Overall experience was great. Flights were almost on time in departing and we arrived at our destination as scheduled. No issues with amenities or flight crew. Everything went well as as expected. Will fly again with American Airlines in the future!

The flight was very smooth and the meal in business class was great.

I requested a low sodium meal. Reason being, I take medicine for high blood pressure and I wear compression socks on long flights to help with leg swelling. Having less sodium in meals really helps me feel better on long flights. I received my initial low sodium meal after takeoff. Just before landing, the crew came through with the meal cart and offered me what was being served. I said no thank you and then noticed my low sodium meal in the meal cart, with my name and seat assignment on it. I motioned to the crew member, but he grabbed the meal cart and proceeded to move to the rear of the aircraft. He didn’t see me or other passengers who had attempted to get this attention. He was more concerned about completing meal service since we were due to land in under 45 minutes. I pressed the call light five times from my seat to receive help, but no crew member responded to me. So, I didn’t receive a second meal, one that I requested (the low sodium option). This led me to have a migraine from only eating one meal on an 11-hour flight. This is why I’m not a fan of flying US-based airlines overseas. The crew members continue to show the absolute worst customer service experience. I would not recommend flying American for overseas flights.

First of all we hade waited 3 hours in the airplane waiting to leave. Second the return schedule was changed and it messed up my entire vaction. I won't buy never again another flight and recommend to nobody traveling with them.

It was ok. It was expensive to check 2 bags ($75.00 per bag), and then it took a long time to wait for shuttle to take us from one terminal to the terminal where the plane was taking off at LAX. And all of this for a flight where we had to pay for any food or drink that was not water.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

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….

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

Information on your arrival and departure airports