Cheap flights from London Heathrow Airport to San Juan from £343

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 4/3. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — SJU
11 Dec — 18 Dec1
1 adult
1 adult, Economy, 0 bags

Cheapflights Tip: The best prices from London Heathrow to San Juan are usually found in September or February, booked 43 days in advance, depart on a Monday or Wednesday and return on a Tuesday

Cheap flight deals from Heathrow to San Juan

Discover tips and strategies to find the most affordable flight options for your journey from Heathrow (LHR) 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 11 November 2025.

Round-trip from

£526

One-way from

£343

Popular in

December

Cheapest in

September

Average price

£585
Icelandair
  • Icelandair
  • 12/1-26/1
  • 3 total stops
  • 31h 47m total
  • London to San Juan
JetBlue
  • JetBlue
  • 4/3
  • 1 total stop
  • 16h 24m total
  • London to San Juan
Highest demand for flights based on searches. 6% potential increase in price (£35 potential increase over avg. return price).
Cheapest flight prices on average. 3% potential price decrease (£19 potential savings vs. average return price).
Average for round-trip flights in November 2025

Find flight deals from Heathrow to San Juan

Enter your travel dates to find the best prices.

Cheapest flights from Heathrow to San Juan
Explore the most affordable flight options available from Heathrow to San Juan. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 11 November 2025.

Sun 7/1207:45LHR - SJU
1 stop24h 03mJetBlue
Sun 14/1206:10SJU - LHR
1 stop20h 45mJetBlue
Deal found 8/11£540
Tue 9/1207:25LHR - SJU
1 stop31h 19mJetBlue
Tue 16/1210:00SJU - LHR
1 stop19h 30mJetBlue
Deal found 8/11£563
Tue 9/1207:25LHR - SJU
1 stop15h 28mIcelandair
Tue 16/1213:45SJU - LHR
1 stop15h 45mIcelandair
Deal found 8/11£569
Fri 5/1212:20LHR - SJU
1 stop19h 28mJetBlue
Fri 12/1213:45SJU - LHR
1 stop15h 45mJetBlue
Deal found 11/11£593
Sun 7/1207:45LHR - SJU
1 stop15h 08mIcelandair
Sun 14/1206:01SJU - LHR
2 stops44h 54mIcelandair
Deal found 8/11£594
Sun 16/1107:45LHR - SJU
1 stop14h 35mJetBlue
Tue 9/1205:15SJU - LHR
1 stop12h 25mJetBlue
Deal found 9/11£621
Tue 30/1207:25LHR - SJU
1 stop15h 24mIcelandair
Sat 10/106:00SJU - LHR
1 stop12h 00mIcelandair
Deal found 10/11£640
Wed 17/1207:25LHR - SJU
1 stop18h 29mIcelandair
Mon 12/106:00SJU - LHR
2 stops23h 30mIcelandair
Deal found 9/11£654
Wed 17/1207:25LHR - SJU
1 stop31h 28mJetBlue
Mon 12/108:15SJU - LHR
1 stop21h 15mJetBlue
Deal found 9/11£668

Cheapflights Fare Finder

 
Customise your flight search to find flights from Heathrow 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 858,174 searches. Data last updated 11 November 2025.
Use the filters below to find and compare flights from London Heathrow Airport to San Juan that are best for you.

Fly from

Heathrow

Fly to

San Juan

Route

Depart

Return

Price

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Wed 11/3

12:20-02:55

1 stop18h 35m

San Juan Luis Munoz Marin Intl

Thu 19/3

11:05-06:55

1 stop15h 50m

£529

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Sun 15/3

12:20-02:55

1 stop18h 35m

San Juan Luis Munoz Marin Intl

Mon 16/3

10:59-09:30

1 stop18h 31m

£539

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Fri 13/3

12:20-01:47

1 stop17h 27m

San Juan Luis Munoz Marin Intl

Wed 18/3

11:05-06:55

1 stop15h 50m

£540

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Fri 13/3

07:25-22:47

1 stop19h 22m

San Juan Luis Munoz Marin Intl

Sun 15/3

00:59-20:45

1 stop15h 46m

£540

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Wed 11/3

12:20-22:44

1 stop14h 24m

San Juan Luis Munoz Marin Intl

Sat 14/3

00:59-20:45

1 stop15h 46m

£540

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Thu 12/3

12:20-01:47

1 stop17h 27m

San Juan Luis Munoz Marin Intl

Wed 18/3

11:05-06:55

1 stop15h 50m

£540

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Tue 17/3

12:20-01:47

1 stop17h 27m

San Juan Luis Munoz Marin Intl

Fri 20/3

00:59-20:45

1 stop15h 46m

£544

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Mon 12/1

12:15-09:47

2 stops25h 32m

San Juan Luis Munoz Marin Intl

Mon 26/1

06:00-19:30

2 stops33h 30m

£545

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Tue 24/3

07:25-20:35

1 stop17h 10m

San Juan Luis Munoz Marin Intl

Mon 30/3

10:55-09:30

1 stop17h 35m

£547

LondonSan Juan

LHR - SJU

LHRSJU

London Heathrow

Thu 12/3

09:20-22:00

1 stop16h 40m

San Juan Luis Munoz Marin Intl

Thu 19/3

11:05-06:55

1 stop15h 50m

£559

Flights are sorted by cheapest return flights first.

Deals found on 9/11

Showing 1-10 of 18 results
1
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Best time to book a flight from Heathrow to San Juan

Have a flexible travel schedule? Discover the best time to fly to San Juan from Heathrow with our price prediction graph.
Estimated return 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 London Heathrow Airport to San Juan

How far ahead should I book a flight from London Heathrow Airport to San Juan?

Use this chart to determine the optimal time to book a return flight from Heathrow to San Juan. Price data was last updated on 7 November 2025.

The best time to book flights from London Heathrow Airport to San Juan is 43 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from London Heathrow Airport to San Juan?

Currently, July is the cheapest month in which you can book a flight from London Heathrow Airport to San Juan (average of £431). Flying from London Heathrow Airport to San Juan in December is currently the most expensive (average of £539). 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 LHR to SJU?

Find hourly flight availability from Heathrow 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 11 November 2025.

A simple way to save on the total cost of your ticket is to fly from London Heathrow Airport to San Juan in the afternoon. If you’re flexible enough to do this you can expect to save up to 12% on your trip compared to booking a flight in the morning.

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 11 November 2025.
Read reviews from past customers who have flown with Finnair, JetBlue, andIcelandair from London Heathrow Airport 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.

Comfort

7.4

Overall

7.6

Entertainment

6.9

Food

6.7

Crew

8.1

Boarding

7.6

Reviews

1 / 20
4.0
Okay

Anonymous,Sept 2025

WAW - HEL

My flight to Europe was cancelled and rebooked. Bags got lost by FinnAir. Flight back home from Europe was cancelled the very next day after we landed. Zero compensation for these back to back cancellations on the exact same trip. Kayak doesn’t help with flight cancellation before trips says to contact trip protection only for trip protection to say it’s up to kayak. Don’t fly FinnAir.

Comfort

7.4

Overall

7.6

Entertainment

6.9

Food

6.7

Crew

8.1

Boarding

7.6

Reviews

1 / 20
4.0
Okay

Anonymous,Sept 2025

WAW - HEL

My flight to Europe was cancelled and rebooked. Bags got lost by FinnAir. Flight back home from Europe was cancelled the very next day after we landed. Zero compensation for these back to back cancellations on the exact same trip. Kayak doesn’t help with flight cancellation before trips says to contact trip protection only for trip protection to say it’s up to kayak. Don’t fly FinnAir.

Comfort

7.4

Overall

7.6

Entertainment

6.9

Food

6.7

Crew

8.1

Boarding

7.6

Reviews

1 / 20
4.0
Okay

Anonymous,Sept 2025

WAW - HEL

My flight to Europe was cancelled and rebooked. Bags got lost by FinnAir. Flight back home from Europe was cancelled the very next day after we landed. Zero compensation for these back to back cancellations on the exact same trip. Kayak doesn’t help with flight cancellation before trips says to contact trip protection only for trip protection to say it’s up to kayak. Don’t fly FinnAir.

Comfort

7.4

Overall

7.6

Entertainment

6.9

Food

6.7

Crew

8.1

Boarding

7.6

Reviews

1 / 20
4.0
Okay

Anonymous,Sept 2025

WAW - HEL

My flight to Europe was cancelled and rebooked. Bags got lost by FinnAir. Flight back home from Europe was cancelled the very next day after we landed. Zero compensation for these back to back cancellations on the exact same trip. Kayak doesn’t help with flight cancellation before trips says to contact trip protection only for trip protection to say it’s up to kayak. Don’t fly FinnAir.

Comfort

7.4

Overall

7.6

Entertainment

6.9

Food

6.7

Crew

8.1

Boarding

7.6

Reviews

1 / 20
4.0
Okay

Anonymous,Sept 2025

WAW - HEL

My flight to Europe was cancelled and rebooked. Bags got lost by FinnAir. Flight back home from Europe was cancelled the very next day after we landed. Zero compensation for these back to back cancellations on the exact same trip. Kayak doesn’t help with flight cancellation before trips says to contact trip protection only for trip protection to say it’s up to kayak. Don’t fly FinnAir.

Comfort

7.4

Overall

7.6

Entertainment

6.9

Food

6.7

Crew

8.1

Boarding

7.6

Reviews

1 / 20
4.0
Okay

Anonymous,Sept 2025

WAW - HEL

My flight to Europe was cancelled and rebooked. Bags got lost by FinnAir. Flight back home from Europe was cancelled the very next day after we landed. Zero compensation for these back to back cancellations on the exact same trip. Kayak doesn’t help with flight cancellation before trips says to contact trip protection only for trip protection to say it’s up to kayak. Don’t fly FinnAir.

Related info for your journey

Find useful and relevant information for your journey from Heathrow to San Juan. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
  • How long is the flight from London Heathrow Airport to San Juan?

    Airlines like JetBlue fly from London Heathrow Airport to San Juan in about 18h 35m. The time it takes to get you to your destination can typically vary by up to . The distance from London Heathrow Airport to San Juan is about 4179 mi.

  • What are the cheapest airlines flying from London Heathrow Airport to San Juan round-trip?

    Our cheapest airline available from London Heathrow Airport to San Juan is Virgin Atlantic. Our recent data shows that you can find tickets from as low as £339 on this airline. Additional options worth looking into are JetBlue and Finnair, starting at £452 and £458 round-trip. Virgin Atlantic is currently priced 47% below the average price you’ll pay for this route.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Heathrow 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 London Heathrow Airport to San Juan?

    Currently, July is the cheapest month in which you can book a flight from London Heathrow Airport to San Juan (average of £431). Flying from London Heathrow Airport to San Juan in December is currently the most expensive (average of £539). 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 Heathrow to San Juan

Discover the top 6 airlines that operate flights from Heathrow 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 858,174 searches. Data last updated 11 November 2025.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest£339Average£1,145FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
JetBlueCheapest£452Average£614FlexibilityNo cancel feeOn-time62%
Search JetBlue flights
FinnairCheapest£458Average£560FlexibilityNo cancel feeOn-time76%
Search Finnair flights
IcelandairCheapest£483Average£654FlexibilityNo cancel feeOn-time76%
Search Icelandair flights
IberiaCheapest£515Average£760FlexibilityNo cancel feeOn-time77%
Search Iberia flights
British AirwaysCheapest£549Average£879FlexibilityNo cancel feeOn-time70%
Search British Airways flights

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