San Juan

$174+ Cheap flights from Ontario (ONT) to San Juan

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 4/18. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SJU
Apr 23 — Apr 301
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Cheap flight deals from Ontario to San Juan

Cheapest flights from Ontario to San Juan
Explore the most affordable flight options available from Ontario to San Juan. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 24, 2026.

This United Airlines deal was found by Cheapflights users on 3/23. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/196:30 pm
ONT
-
SJU
2 stops14h 27m
United Airlines
Tue 10/277:10 am
SJU
-
ONT
2 stops16h 10m
United Airlines
Deal found 3/23$354
This United Airlines deal was found by Cheapflights users on 3/22. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/127:00 am
ONT
-
SJU
1 stop10h 00m
United Airlines
Wed 11/182:25 pm
SJU
-
ONT
1 stop9h 55m
United Airlines
Deal found 3/22$377
This Delta deal was found by Cheapflights users on 3/20. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/1810:15 pm
ONT
-
SJU
1 stop10h 30m
Delta
Fri 4/2412:55 pm
SJU
-
ONT
1 stop11h 05m
Delta
Deal found 3/20$388
This American Airlines deal was found by Cheapflights users on 3/20. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/110:26 pm
ONT
-
SJU
1 stop19h 25m
American Airlines
Wed 5/67:25 am
SJU
-
ONT
1 stop16h 42m
American Airlines
Deal found 3/20$402
This Frontier deal was found by Cheapflights users on 3/18. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/44:15 pm
ONT
-
SJU
1 stop10h 38m
Frontier
Wed 8/126:15 am
SJU
-
ONT
1 stop12h 10m
Frontier
Deal found 3/18$406
This United Airlines deal was found by Cheapflights users on 3/22. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/257:00 am
ONT
-
SJU
2 stops13h 50m
United Airlines
Thu 4/301:00 am
SJU
-
ONT
2 stops14h 22m
United Airlines
Deal found 3/22$411
This United Airlines deal was found by Cheapflights users on 3/21. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/156:05 am
ONT
-
SJU
1 stop11h 33m
United Airlines
Thu 4/161:00 am
SJU
-
ONT
2 stops14h 20m
United Airlines
Deal found 3/21$415
This United Airlines deal was found by Cheapflights users on 3/22. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/246:45 pm
ONT
-
SJU
2 stops14h 49m
United Airlines
Tue 4/281:40 pm
SJU
-
ONT
1 stop9h 56m
United Airlines
Deal found 3/22$428
This American Airlines deal was found by Cheapflights users on 3/22. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/184:52 pm
ONT
-
SJU
2 stops13h 21m
American Airlines
Fri 5/2212:44 am
SJU
-
ONT
1 stop11h 47m
American Airlines
Deal found 3/22$442
This United Airlines deal was found by Cheapflights users on 3/22. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/287:00 am
ONT
-
SJU
1 stop10h 00m
United Airlines
Wed 11/42:25 pm
SJU
-
ONT
1 stop9h 55m
United Airlines
Deal found 3/22$444
This Southwest deal was found by Cheapflights users on 3/20. 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.
Fri 5/89:55 pm
ONT
-
SJU
1 stop9h 30m
Southwest
Fri 5/155:05 am
SJU
-
ONT
2 stops13h 10m
Southwest
Deal found 3/20$446
This Kiwi.com deal was found by Cheapflights users on 3/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/298:05 am
ONT
-
SJU
1 stop12h 05m
Multiple Airlines
Mon 5/46:30 am
SJU
-
ONT
2 stops44h 19m
Multiple Airlines
Deal found 3/21$448

Find flight deals from Ontario to San Juan

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to San Juan (PR1). 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 March 24, 2026.

Round-trip from

$354
(American Airlines)

One-way from

$174
(Trip.com)

Popular in

December

Cheapest in

October

Average price

$585
From Ontario to San Juan
One-way flight from Ontario to San Juan
Highest demand for flights based on searches. 11% potential increase in price ($76 potential increase over avg. RT price).
Cheapest flight prices on average. 3% potential price decrease ($22 potential savings vs. average RT price).
Average for round-trip flights in March 2026

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to San Juan 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 March 24, 2026.
Use the filters below to find and compare flights from Ontario to San Juan that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 4/27

6:49 pm-1:45 pm

2 stops15h 56m

San Juan Luis Munoz Marin Intl

Thu 4/30

1:00 am-12:22 pm

2 stops14h 22m

$478

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 4/27

6:05 am-8:38 pm

1 stop11h 33m

San Juan Luis Munoz Marin Intl

Wed 4/29

1:00 am-12:22 pm

2 stops14h 22m

$512

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 4/20

5:10 am-5:38 pm

1 stop9h 28m

San Juan Luis Munoz Marin Intl

Fri 4/24

7:00 am-10:45 pm

2 stops18h 45m

$524

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 3/31

5:10 am-8:38 pm

2 stops12h 28m

San Juan Luis Munoz Marin Intl

Tue 4/7

2:55 pm-9:50 pm

1 stop9h 55m

$590
Quickest round-trip

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 4/20

5:10 am-5:38 pm

1 stop9h 28m

San Juan Luis Munoz Marin Intl

Wed 4/29

1:40 pm-8:36 pm

1 stop9h 56m

$591

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 4/14

6:05 am-8:38 pm

1 stop11h 33m

San Juan Luis Munoz Marin Intl

Sat 4/18

1:40 pm-8:36 pm

1 stop9h 56m

$595

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Fri 4/17

10:15 pm-11:45 am

1 stop10h 30m

San Juan Luis Munoz Marin Intl

Fri 4/24

12:55 pm-9:00 pm

1 stop11h 05m

$604

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Wed 4/1

5:10 am-5:38 pm

1 stop9h 28m

San Juan Luis Munoz Marin Intl

Wed 4/8

7:00 am-8:36 pm

2 stops16h 36m

$665

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Sat 4/4

5:10 am-8:38 pm

2 stops12h 28m

San Juan Luis Munoz Marin Intl

Wed 4/8

7:00 am-8:36 pm

2 stops16h 36m

$723

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 4/6

7:00 am-8:34 pm

1 stop10h 34m

San Juan Luis Munoz Marin Intl

Wed 4/8

2:55 pm-9:50 pm

1 stop9h 55m

$746

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/19

Showing 1-10 of 22 resultsSorted by cheapest first
1
2
3

Best time to book a flight from Ontario to San Juan

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

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

Use this chart to determine the optimal time to book a round-trip flight from Ontario to San Juan. Price data was last updated on March 13, 2026.

To ensure you get the cheapest price possible for a flight from Ontario to San Juan, you should look to book at least 24 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 Ontario to San Juan?

Currently, April is the cheapest month in which you can book a flight from Ontario to San Juan (average of $141). Flying from Ontario to San Juan in February is currently the most expensive (average of $295). 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.

Reviews of airlines servicing San Juan

Get insights into the airlines that provide service to San Juan. 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 San Juan. Reviews last updated March 24, 2026.
Read reviews from past customers who have flown Southwest,Delta, andUnited Airlines from Ontario to San Juan. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.

Crew

8.6

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Food

7.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Crew

8.6

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Food

7.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Crew

8.6

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Food

7.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Crew

8.6

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Food

7.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Crew

8.6

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Food

7.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Crew

8.6

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Food

7.0

Overall

8.0

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Related info for your journey

Find useful and relevant information for your journey from Ontario to San Juan. 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 from for flights from Ontario to San Juan?

    If you book a flight to San Juan from Ontario, you will be flying from Ontario, which is the city’s only airport. Ontario (ONT) is located 3.1 mi from the center of Ontario. There are 0 flights from Ontario to San Juan per day from 6 different airlines.

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

    Airlines like United Airlines fly from Ontario to San Juan in about 15h 56m. The time it takes to get you to your destination can typically vary by up to . Airlines will cover a distance of 3334 mi.

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

    Frontier, at $137, was found to be the cheapest airline from Ontario to San Juan.Alternate airlines to your destination round-trip include Delta and United Airlines. Frontier is currently priced 76% below the average price you’ll pay for this route.

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

    $142 is the cheapest one-way deal found within the past few days, from United Airlines. You may also be able to find cheap deals on Southwest and American Airlines, with prices starting from $178 and $230, respectively.

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

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

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

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

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

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

    Currently, April is the cheapest month in which you can book a flight from Ontario to San Juan (average of $141). Flying from Ontario to San Juan in February is currently the most expensive (average of $295). 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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Top 6 airlines flying from Ontario to San Juan

Discover the top 6 airlines that operate flights from Ontario to San Juan. 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 March 24, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$137Average$467FlexibilityNo cancel feeOn-time62%
DeltaCheapest$292Average$597FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$321Average$551FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$365Average$577FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$445Average$560FlexibilityNo cancel feeOn-time63%
JetBlueCheapest$455Average$492FlexibilityNo cancel feeOn-time62%

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