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San Juan

$178+ 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 1/16. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SJU
Dec 1 — Dec 81
Mon 12/1
Mon 12/8
1 adult, Economy
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Cheapflights Tip: The best prices from Ontario to San Juan are usually found in October or April, booked 24 days in advance, depart on a Tuesday or Monday and return on a Wednesday

Cheap 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 November 1, 2025.

Round-trip from

$236
(Frontier)

One-way from

$178
(Delta)

Popular in

December

Cheapest in

October

Average price

$590
From Ontario to San Juan
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One-way flight from Ontario to San Juan
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Highest demand for flights based on searches. 9% potential increase in price ($61 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($15 potential savings vs. average RT price).
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Average for round-trip flights in November 2025
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Find 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 November 1, 2025.

This Frontier deal was found by Cheapflights users on 10/30. 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.
Fri 12/53:20 pmONT - SJU
2 stops20h 14mFrontier
Sun 12/71:59 amSJU - ONT
2 stops18h 34mFrontier
Deal found 10/30$236
This Frontier deal was found by Cheapflights users on 10/30. 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.
Mon 11/107:24 pmONT - SJU
2 stops18h 30mFrontier
Fri 11/143:59 amSJU - ONT
2 stops12h 38mFrontier
Deal found 10/30$282
This Frontier deal was found by Cheapflights users on 10/30. 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 11/164:05 pmONT - SJU
2 stops15h 14mFrontier
Wed 11/199:00 amSJU - ONT
2 stops16h 27mFrontier
Deal found 10/30$302
This Frontier deal was found by Cheapflights users on 10/31. 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.
Mon 12/85:18 pmONT - SJU
2 stops21h 05mFrontier
Thu 12/111:59 amSJU - ONT
2 stops18h 34mFrontier
Deal found 10/31$308
This Frontier deal was found by Cheapflights users on 10/30. 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 11/198:00 amONT - SJU
2 stops21h 56mFrontier
Sat 11/227:11 amSJU - ONT
2 stops15h 02mFrontier
Deal found 10/30$312
This Frontier deal was found by Cheapflights users on 10/30. 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.
Thu 11/203:31 pmONT - SJU
2 stops20h 24mFrontier
Sun 11/233:59 amSJU - ONT
2 stops14h 27mFrontier
Deal found 10/30$313
This Kiwi.com deal was found by Cheapflights users on 10/31. 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.
Thu 12/117:33 pmONT - SJU
1 stop25h 02mMultiple Airlines
Sun 12/146:00 amSJU - ONT
1 stop14h 33mMultiple Airlines
Deal found 10/31$327
This Frontier deal was found by Cheapflights users on 10/29. 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.
Thu 11/203:31 pmONT - SJU
2 stops20h 24mFrontier
Sat 11/229:30 pmSJU - ONT
2 stops17h 58mFrontier
Deal found 10/29$328
This Frontier deal was found by Cheapflights users on 10/31. 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 11/164:05 pmONT - SJU
2 stops14h 56mFrontier
Wed 11/193:59 amSJU - ONT
2 stops14h 27mFrontier
Deal found 10/31$340

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 November 1, 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

Fri 12/5

2:05 pm-11:25 pm

1 stop29h 20m

San Juan Luis Munoz Marin Intl

Thu 12/11

1:59 am-4:33 pm

2 stops18h 34m

$354

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Thu 12/4

7:33 pm-12:35 am

1 stop25h 02m

San Juan Luis Munoz Marin Intl

Wed 12/10

5:00 pm-6:35 pm

2 stops29h 35m

$376

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Thu 12/4

10:34 pm-10:09 pm

1 stop19h 35m

San Juan Luis Munoz Marin Intl

Wed 12/10

7:00 am-6:17 pm

1 stop15h 17m

$414

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Tue 3/3

5:00 am-6:25 pm

1 stop9h 25m

San Juan Luis Munoz Marin Intl

Thu 3/5

3:46 pm-10:35 pm

1 stop10h 49m

$445

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Sat 2/21

1:53 pm-6:11 am

2 stops12h 18m

San Juan Luis Munoz Marin Intl

Fri 2/27

2:05 am-5:41 pm

3 stops19h 36m

$445

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Thu 12/4

6:30 pm-10:25 am

2 stops11h 55m

San Juan Luis Munoz Marin Intl

Wed 12/10

11:20 am-8:55 pm

2 stops13h 35m

$455

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Fri 12/5

5:55 am-9:30 pm

2 stops11h 35m

San Juan Luis Munoz Marin Intl

Fri 12/12

7:40 am-4:00 pm

2 stops12h 20m

$455

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Fri 11/28

5:05 am-6:25 pm

1 stop9h 20m

San Juan Luis Munoz Marin Intl

Fri 12/5

7:45 am-8:42 pm

2 stops16h 57m

$520

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Mon 1/26

10:30 pm-1:05 pm

1 stop10h 35m

$178

OntarioSan Juan

ONT - SJU

ONTSJU

Ontario

Sun 1/25

10:30 pm-1:05 pm

1 stop10h 35m

$178

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/31

Showing 1-10 of 18 results
1
2

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 October 31, 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 $133). 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 November 1, 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 morning could potentially save you up to 33% 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 November 1, 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
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Overall

8.0

Entertainment

7.5

Crew

8.6

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Southwest
8.0
Very good
4,241 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Overall

8.0

Entertainment

7.5

Crew

8.6

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Delta
7.9
Good
7,997 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Overall

8.0

Entertainment

7.5

Crew

8.6

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
United Airlines
7.4
Good
8,994 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Overall

8.0

Entertainment

7.5

Crew

8.6

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
American Airlines
7.2
Good
11,033 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Overall

8.0

Entertainment

7.5

Crew

8.6

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Frontier
5.8
Fair
3,120 reviews
Southwest
8.0
Very good
4,241 reviews

Food

7.0

Comfort

8.0

Overall

8.0

Entertainment

7.5

Crew

8.6

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.

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 American Airlines and 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 10h 10m. Airlines will cover a distance of 3334 mi. This flight may include one or multiple stops.

  • 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 American Airlines and United Airlines. Frontier is currently priced 87% below the average price you’ll pay for this route.

  • 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 $133). 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.

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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 November 1, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$73Average$467FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$364Average$610FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$366Average$585FlexibilityNo cancel feeOn-time69%
DeltaCheapest$375Average$534FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$409Average$598FlexibilityNo cancel feeOn-time63%

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