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Cheap flights from Islip, New York to London Heathrow Airport from £850

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 29/9. Fares are subject to change and may not be available on all flights or dates of travel.
ISP — LHR
22 Aug — 29 Aug1
1 adult

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 17 August 2025.

Round-trip from

£850

Popular in

December

Cheapest in

January

Average price

£412
29/9-6/10
  • 29/9-6/10
  • 2 total stops
  • 22h 22m total
  • Islip to London
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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 (£7 potential savings vs. average return price).
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Average for round-trip flights in August 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 17 August 2025.

Mon 29/914:19ISP - LHR
1 stop12h 01mMultiple Airlines
Mon 6/1014:40LHR - ISP
1 stop10h 21mMultiple Airlines
Deal found 15/8£850
Wed 1/1016:33ISP - LHR
2 stops37h 27mMultiple Airlines
Wed 8/1020:10LHR - ISP
1 stop19h 48mMultiple Airlines
Deal found 17/8£1,044

Cheapflights Fare Finder

 
Customise 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 858,174 searches. Data last updated 17 August 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

Mon 29/9

14:19-07:20

1 stop12h 01m

London Heathrow

Mon 6/10

14:40-20:01

1 stop10h 21m

£850

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Wed 1/10

16:33-11:00

2 stops37h 27m

London Heathrow

Wed 8/10

20:10-10:58

1 stop19h 48m

£1,044

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Mon 5/1

16:33-09:15

2 stops11h 42m

£1,098

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Sun 4/1

14:19-09:15

2 stops13h 56m

£1,104

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Mon 2/2

16:33-09:15

2 stops11h 42m

£1,113

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Thu 13/11

16:33-09:15

2 stops11h 42m

£1,113

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Fri 16/1

16:33-09:15

2 stops11h 42m

£1,113

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Sat 15/11

16:33-09:15

2 stops11h 42m

£1,113

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Sat 3/1

16:33-09:15

2 stops11h 42m

£1,113

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Tue 10/2

16:33-09:15

2 stops11h 42m

£1,113

Flights are sorted by cheapest return flights first.

Deals found on 17/8

Showing 1-10 of 12 results
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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 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 Islip to London Heathrow Airport

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

Currently, January is the cheapest month in which you can book a flight from Islip, New York to London Heathrow Airport (average of £112). Flying from Islip, New York to London Heathrow Airport in August is currently the most expensive (average of £164). 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?

    For a flight from Islip to London Heathrow, you will be flying from Long Island. Islip Long Island (ISP) is just 7.2 mi from the center of the city. Long Island is the only Islip airport and it handles 0 outbound flights to London Heathrow per day. 0 airlines have flights to London Heathrow from Islip Long Island on a regular basis.

  • 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 holiday 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, New York to London Heathrow Airport?

    Currently, January is the cheapest month in which you can book a flight from Islip, New York to London Heathrow Airport (average of £112). Flying from Islip, New York to London Heathrow Airport in August is currently the most expensive (average of £164). 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

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Milton Keynes
Croydon
Hounslow
Gatwick
Slough
Northampton
Deal
Luton
Wembley
Crawley
Ilford
Hayes
Ipswich
Southend-on-Sea
Winchester
Folkestone
Eastbourne
Maidstone
Watford
Chichester

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Islip to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
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Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Islip to Heathrow?

Cheapflights goes through 900+ travel sites to look for the best flight deals for flights from Islip to Heathrow. Too many options? Cheapflights also provides filters for things like airlines, price ranges, and number of stops to help you make a decision easily.

Why should you use Cheapflights to find cheap flight tickets from Islip to Heathrow?

Cheapflights helps you find that perfect flight to Heathrow from Islip by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Islip to Heathrow with no change fees?

Yes! Cheapflights helps users easily find flights from Islip to Heathrow with no change fees.

Can Cheapflights notify me if prices for flights from Islip to Heathrow become cheaper?

Yes, Cheapflights has a feature called Price Alert, which notifies users when flight prices change. Track prices for your flight to Heathrow from Islip today and book when prices fit your budget.

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