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San Juan

$103+ 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 1/1. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SJU
Jan 17 — Jan 241
Sat 1/17
Sat 1/24
1 adult, Economy
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1. Tell us where you want to go

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Cheapflights Tip: The best prices from Ontario to San Juan are usually found in October or February, booked 24 days in advance, depart on a Tuesday or Monday and return on a Wednesday

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 December 18, 2025.

This Frontier deal was found by Cheapflights users on 12/16. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/203:27 pmONT - SJU
1 stop11h 07mFrontier
Mon 12/227:06 pmSJU - ONT
1 stop16h 18mFrontier
Deal found 12/16$394
This CheapOair deal was found by Cheapflights users on 12/16. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/184:16 pmONT - SJU
1 stop10h 18mFrontier
Mon 12/227:06 pmSJU - ONT
1 stop16h 18mFrontier
Deal found 12/16$395
This Frontier deal was found by Cheapflights users on 12/15. 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.
Sun 12/214:41 pmONT - SJU
1 stop9h 53mFrontier
Thu 1/17:06 pmSJU - ONT
1 stop16h 13mFrontier
Deal found 12/15$414
This Frontier deal was found by Cheapflights users on 12/17. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/314:22 pmONT - SJU
1 stop10h 12mFrontier
Thu 1/17:06 pmSJU - ONT
1 stop16h 13mFrontier
Deal found 12/17$434
This Frontier deal was found by Cheapflights users on 12/17. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/284:41 pmONT - SJU
1 stop9h 53mFrontier
Mon 12/297:06 pmSJU - ONT
1 stop16h 18mFrontier
Deal found 12/17$444
This CheapOair deal was found by Cheapflights users on 12/16. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/203:27 pmONT - SJU
1 stop11h 07mFrontier
Thu 12/257:06 pmSJU - ONT
1 stop16h 13mFrontier
Deal found 12/16$445
This Frontier deal was found by Cheapflights users on 12/15. 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.
Sat 12/203:27 pmONT - SJU
1 stop11h 07mFrontier
Thu 1/17:06 pmSJU - ONT
1 stop16h 13mFrontier
Deal found 12/15$464
This Trip.com deal was found by Cheapflights users on 12/16. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/314:22 pmONT - SJU
1 stop10h 12mFrontier
Sat 1/33:55 amSJU - ONT
2 stops21h 32mFrontier
Deal found 12/16$476
This Frontier deal was found by Cheapflights users on 12/17. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/284:41 pmONT - SJU
1 stop9h 53mFrontier
Thu 1/17:06 pmSJU - ONT
1 stop16h 13mFrontier
Deal found 12/17$494
This Frontier deal was found by Cheapflights users on 12/16. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/234:41 pmONT - SJU
1 stop9h 53mFrontier
Thu 1/17:06 pmSJU - ONT
1 stop16h 13mFrontier
Deal found 12/16$514
This Trip.com deal was found by Cheapflights users on 12/16. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/304:41 pmONT - SJU
1 stop9h 53mFrontier
Mon 1/57:25 amSJU - ONT
2 stops17h 52mFrontier
Deal found 12/16$534
This Trip.com deal was found by Cheapflights users on 12/16. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/314:22 pmONT - SJU
1 stop10h 12mFrontier
Mon 1/57:25 amSJU - ONT
2 stops17h 52mFrontier
Deal found 12/16$561

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 December 18, 2025.

Round-trip from

$283
(American Airlines)

One-way from

$103
(CheapOair)

Popular in

June

Cheapest in

October

Average price

$655
From Ontario to San Juan
Search Deals
One-way flight from Ontario to San Juan
Search Deals
Highest demand for flights based on searches. 15% potential increase in price ($104 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($11 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

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 December 18, 2025.
Use the filters below to find and compare flights from Ontario to San Juan that are best for you.

Fly from

Ontario

Fly to

San Juan

Route

Depart

Return

Price

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Sun 3/1

5:00 am-6:25 pm

1 stop9h 25m

San Juan Luis Munoz Marin Intl

Wed 3/4

3:46 pm-9:59 pm

1 stop10h 13m

$283

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Wed 4/29

7:00 am-8:34 pm

1 stop10h 34m

San Juan Luis Munoz Marin Intl

Wed 5/6

2:55 pm-9:50 pm

1 stop9h 55m

$312

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 2/24

8:00 am-9:26 pm

1 stop9h 26m

San Juan Luis Munoz Marin Intl

Wed 2/25

2:05 am-5:41 pm

3 stops19h 36m

$373

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Sun 1/18

1:53 pm-6:11 am

2 stops12h 18m

San Juan Luis Munoz Marin Intl

Thu 1/22

7:45 am-5:43 pm

2 stops13h 58m

$373

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 5/5

11:25 pm-12:49 pm

1 stop10h 24m

San Juan Luis Munoz Marin Intl

Tue 5/19

1:50 pm-10:09 pm

1 stop11h 19m

$374

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Wed 5/6

11:25 pm-1:47 pm

1 stop11h 22m

San Juan Luis Munoz Marin Intl

Mon 5/11

1:50 pm-10:09 pm

1 stop11h 19m

$400

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 5/18

10:10 am-11:55 pm

2 stops10h 45m

San Juan Luis Munoz Marin Intl

Sat 5/23

10:00 am-10:00 pm

1 stop15h 00m

$428

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 4/14

6:00 am-8:38 pm

1 stop11h 38m

San Juan Luis Munoz Marin Intl

Tue 4/21

1:40 pm-8:46 pm

1 stop10h 06m

$430

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 1/13

10:30 pm-1:05 pm

1 stop10h 35m

San Juan Luis Munoz Marin Intl

Wed 1/21

2:15 pm-9:05 pm

1 stop10h 50m

$477

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Thu 3/12

6:00 am-10:31 pm

1 stop13h 31m

$142

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/16

Showing 1-10 of 18 results
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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 December 12, 2025.

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 $137). Flying from Ontario to San Juan in November is currently the most expensive (average of $286). 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 ONT to SJU?

Find hourly flight availability from Ontario to San Juan. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 18, 2025.

One of the essential ways to save on airfare from Ontario to San Juan is to remain as flexible as possible. Flights that are in the afternoon tend to be the most expensive. A flight in the evening could potentially save you up to 38% on airfare.

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 December 18, 2025.
Read reviews from past customers who have flown Southwest, Delta, and United 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.
Southwest
7.9
Good
4,250 reviews

Food

7.0

Overall

7.9

Comfort

8.0

Crew

8.6

Entertainment

7.5

Boarding

8.1

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.
Southwest
7.9
Good
4,250 reviews
Southwest
7.9
Good
4,250 reviews

Food

7.0

Overall

7.9

Comfort

8.0

Crew

8.6

Entertainment

7.5

Boarding

8.1

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.
Delta
7.9
Good
8,005 reviews
Southwest
7.9
Good
4,250 reviews

Food

7.0

Overall

7.9

Comfort

8.0

Crew

8.6

Entertainment

7.5

Boarding

8.1

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.
United Airlines
7.4
Good
9,091 reviews
Southwest
7.9
Good
4,250 reviews

Food

7.0

Overall

7.9

Comfort

8.0

Crew

8.6

Entertainment

7.5

Boarding

8.1

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.
American Airlines
7.2
Good
11,054 reviews
Southwest
7.9
Good
4,250 reviews

Food

7.0

Overall

7.9

Comfort

8.0

Crew

8.6

Entertainment

7.5

Boarding

8.1

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.
Frontier
5.8
Fair
3,081 reviews
Southwest
7.9
Good
4,250 reviews

Food

7.0

Overall

7.9

Comfort

8.0

Crew

8.6

Entertainment

7.5

Boarding

8.1

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 5 different airlines.

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

    Airlines like United Airlines fly from Ontario to San Juan in about 9h 25m. 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 $73, 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 87% below the average price you’ll pay for this route.

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

    $168 is the cheapest one-way deal found within the past few days, from Delta. You may also be able to find cheap deals on American Airlines and United Airlines, with prices starting from $172 and $178, 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 $137). Flying from Ontario to San Juan in November is currently the most expensive (average of $286). 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 5 airlines flying from Ontario to San Juan

Discover the top 5 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 December 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$73Average$467FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$321Average$555FlexibilityNo cancel feeOn-time69%
DeltaCheapest$355Average$518FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$365Average$617FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$480Average$610FlexibilityNo cancel feeOn-time63%

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