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Cheap flights from Islip, New York to London from $346

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Islip, New York to London departing on 12/1. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Islip, New York to London

Cheap round-trip flights

Enter your travel dates to find the best prices.
JetBlue Logo
11:50 am - 9:30 amISP-LHR
16h 40m2 stops
JetBlue Logo
9:20 am - 6:45 pmLHR-ISP
38h 25m2 stops
$1,651JetBlue
Find Deal
Tue, Dec 16 - Tue, Dec 23
Multiple Airlines Logo
12:30 pm - 11:20 amISP-LHR
17h 50m2 stops
Multiple Airlines Logo
6:00 am - 7:45 pmLHR-ISP
18h 45m2 stops
$1,906Multiple Airlines
Find Deal
Wed, Dec 31 - Wed, Jan 7
Multiple Airlines Logo
9:59 am - 3:50 pmISP-LHR
24h 51m3 stops
Multiple Airlines Logo
6:00 am - 7:45 pmLHR-ISP
18h 45m2 stops
$1,938Multiple Airlines
Find Deal
Wed, Dec 31 - Wed, Jan 7
Multiple Airlines Logo
9:59 am - 3:50 pmISP-LHR
24h 51m3 stops
Multiple Airlines Logo
6:50 am - 7:45 pmLHR-ISP
17h 55m3 stops
$1,972Multiple Airlines
Find Deal
Wed, Dec 31 - Wed, Jan 7
Multiple Airlines Logo
7:25 am - 12:40 pmISP-LHR
24h 15m2 stops
Multiple Airlines Logo
9:20 am - 4:10 pmLHR-ISP
11h 50m1 stop
$1,998Multiple Airlines
Find Deal
Sun, Jan 11 - Sun, Jan 18
Multiple Airlines Logo
12:30 pm - 11:25 amISP-LHR
17h 55m2 stops
Multiple Airlines Logo
9:20 am - 4:10 pmLHR-ISP
11h 50m1 stop
$2,493Multiple Airlines
Find Deal
Wed, Dec 31 - Wed, Jan 7
Multiple Airlines Logo
12:30 pm - 6:55 amISP-LHR
13h 25m1 stop
Multiple Airlines Logo
6:00 am - 7:45 pmLHR-ISP
18h 45m2 stops
$2,792Multiple Airlines
Find Deal
Tue, Dec 16 - Tue, Dec 23
Multiple Airlines Logo
12:30 pm - 6:55 amISP-LHR
13h 25m1 stop
Multiple Airlines Logo
9:20 am - 4:10 pmLHR-ISP
11h 50m1 stop
$3,156Multiple Airlines
Find Deal
Tue, Dec 16 - Tue, Dec 23
Multiple Airlines Logo
12:30 pm - 6:55 amISP-LHR
13h 25m1 stop
Multiple Airlines Logo
9:20 am - 4:10 pmLHR-ISP
11h 50m1 stop
$3,605Multiple Airlines
Find Deal
Wed, Dec 31 - Wed, Jan 7

momondo Fare Finder

 
Customize your flight search to find flights from Islip, New York to London Heathrow Airport 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, momondo users made 832,500 searches. Data last updated November 18, 2025.
Use the filters below to find and compare flights from Islip, New York to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Tue 12/16

11:50 am-9:30 am

2 stops16h 40m

London Heathrow

Tue 12/23

9:20 am-6:45 pm

2 stops38h 25m

$1,651

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Wed 12/31

12:30 pm-11:20 am

2 stops17h 50m

London Heathrow

Wed 1/7

6:00 am-7:45 pm

2 stops18h 45m

$1,906

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Wed 12/31

9:59 am-3:50 pm

3 stops24h 51m

London Heathrow

Wed 1/7

6:00 am-7:45 pm

2 stops18h 45m

$1,938

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Wed 12/31

9:59 am-3:50 pm

3 stops24h 51m

London Heathrow

Wed 1/7

6:50 am-7:45 pm

3 stops17h 55m

$1,972

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Sun 1/11

7:25 am-12:40 pm

2 stops24h 15m

London Heathrow

Sun 1/18

9:20 am-4:10 pm

1 stop11h 50m

$1,998

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Wed 12/31

12:30 pm-11:25 am

2 stops17h 55m

London Heathrow

Wed 1/7

9:20 am-4:10 pm

1 stop11h 50m

$2,493

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Tue 12/16

12:30 pm-6:55 am

1 stop13h 25m

London Heathrow

Tue 12/23

6:00 am-7:45 pm

2 stops18h 45m

$2,792

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Tue 12/16

12:30 pm-6:55 am

1 stop13h 25m

London Heathrow

Tue 12/23

9:20 am-4:10 pm

1 stop11h 50m

$3,156

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Wed 12/31

12:30 pm-6:55 am

1 stop13h 25m

London Heathrow

Wed 1/7

9:20 am-4:10 pm

1 stop11h 50m

$3,605

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Mon 12/1

9:02 am-10:50 am

3 stops44h 48m

$346

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 13 resultsSorted by cheapest first
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See travel insights to London from

How to get the cheapest flight ticket from Islip, New York to London Heathrow Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to London Heathrow Airport?

Our data shows that Wednesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $643. The most expensive day to fly to London Heathrow Airport is Sunday, with ticket prices averaging around $683.

What is the cheapest time of day to depart on your flight to London Heathrow Airport?

According to our data, the cheapest time of day to fly to London Heathrow Airport is at noon. momondo users have found flights departing from Islip, New York to London Heathrow Airport at noon for as low as $586. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the afternoon are often more expensive with an average ticket price of $693.

When to book flights from Islip, New York to London Heathrow Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Islip, New York to London Heathrow Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Islip, New York to London Heathrow Airport (ISP to LHR) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Islip, New York to London Heathrow Airport

Direct flights

None
There are no direct flights from Islip, New York to London Heathrow Airport. There are no popular flight routes from Islip, New York to London Heathrow Airport.
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  • How far is Islip Long Island to London Heathrow by plane?

    A flight from Islip Long Island to London Heathrow will travel around 3412.8 mi. Typically, this will take 13h 25m by plane in normal conditions.

  • When did momondo last update prices for flights from Islip Long Island Airport to London Heathrow Airport?

    Prices for flights from Islip Long Island Airport to London Heathrow Airport are refreshed on a daily basis.

  • How old do you have to be to fly from Islip Long Island Airport to London Heathrow Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Islip Long Island Airport to London Heathrow Airport.

  • What documentation or ID do you need to fly to London Heathrow Airport?

    The necessary travel and health documents for your London Heathrow Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Gatwick
Hounslow
Milton Keynes
Dover
Luton
Slough
Guildford
Hayes
Dartford
Stratford-upon-Avon
Crawley
Brentwood
Chelmsford
Salisbury
Wembley
Folkestone
Romford
Ilford
Cobham
Swindon

Why use momondo?

Why should I use momondo to find a flight deal from Islip to London?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to London from Islip.

Can I find flights from Islip to London with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to London from Islip with this policy.

How can momondo help me find flights from Islip to London?

momondo provides multiple filters to help you find the best flight to London from Islip. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from Islip to London right now. Can momondo alert me if prices change?

Yes. momondo can track prices for Islip to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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