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$1,045+ Cheap flights from Islip (ISP) to Heathrow (LHR)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/4. Fares are subject to change and may not be available on all flights or dates of travel.
ISP — LHR
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
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Cheap flight deals from Islip to Heathrow

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

Round-trip from

$1,045
(Mytrip)

Popular in

December

Cheapest in

January

Average price

$515
From Islip Long Island to London Heathrow
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High demand for flights, 3% potential price rise
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Cheapest flight prices on average. 2% potential price decrease ($12 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Islip to Heathrow

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

This Mytrip deal was found by Cheapflights users on 9/10. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/411:53 amISP - LHR
2 stops16h 22mMultiple Airlines
Sun 12/148:50 amLHR - ISP
2 stops16h 11mMultiple Airlines
Deal found 9/10$1,045
This Mytrip deal was found by Cheapflights users on 9/11. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/104:33 pmISP - LHR
2 stops32h 57mMultiple Airlines
Tue 10/146:00 amLHR - ISP
2 stops19h 01mMultiple Airlines
Deal found 9/11$1,627
This United deal was found by Cheapflights users on 9/10. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/52:19 pmISP - LHR
2 stops15h 06mMultiple Airlines
Sun 12/148:00 amLHR - ISP
2 stops17h 01mMultiple Airlines
Deal found 9/10$6,215

Cheapflights Fare Finder

 
Customize your flight search to find flights from Islip to Heathrow 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 September 11, 2025.
Use the filters below to find and compare flights from Islip to London Heathrow Airport that are best for you.

Fly from

Islip

Fly to

Heathrow

Route

Depart

Return

Price

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Thu 12/4

11:53 am-9:15 am

2 stops16h 22m

London Heathrow

Sun 12/14

8:50 am-8:01 pm

2 stops16h 11m

$1,045

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Fri 10/10

4:33 pm-6:30 am

2 stops32h 57m

London Heathrow

Tue 10/14

6:00 am-8:01 pm

2 stops19h 01m

$1,627

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Fri 12/5

2:19 pm-10:25 am

2 stops15h 06m

London Heathrow

Sun 12/14

8:00 am-8:01 pm

2 stops17h 01m

$6,215

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/10

Best time to book a flight from Islip to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Islip 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 Islip to London Heathrow Airport

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

Currently, November is the cheapest month in which you can book a flight from Islip to London Heathrow Airport (average of $661). Flying from Islip to London Heathrow Airport in June is currently the most expensive (average of $1,098). 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.

Related info for your journey

Find useful and relevant information for your journey from Islip to Heathrow. 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 Islip to London Heathrow?

    Islip Long Island (ISP), located 7.2 mi from the city center, is the airport you fly out of when you book flights from Islip to London Heathrow. 0 airlines have flights from Long Island to London Heathrow on a regular basis. Booking flights from Islip Long Island to London Heathrow should not be difficult; the airport handles an average of 0 outbound flights to London Heathrow per day.

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

    Yes. In addition to deals on Islip to Heathrow flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Islip to Heathrow?

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

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

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

    Currently, November is the cheapest month in which you can book a flight from Islip to London Heathrow Airport (average of $661). Flying from Islip to London Heathrow Airport in June is currently the most expensive (average of $1,098). 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

Traveling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Hounslow
Hayes
Thornton Heath
Southend-on-Sea
Harrow
Canterbury
Croydon
Eastleigh
Dartford
Dover
Winchester
Orpington
Northampton
Gatwick
Borehamwood
Broadway
Aylesbury
Bedford
Wembley
Folkestone

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