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Cheap flights from Islip to London from $950

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from Islip to London departing on 10/22. 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 to London

Cheap round-trip flights

JetBlue Logo
11:35 am - 8:45 pmISP-LHR
28h 10m2 stops
JetBlue Logo
7:25 am - 1:02 pmLHR-ISP
33h 37m2 stops
$950JetBlue
Find Deal
Wed, Oct 22 - Wed, Oct 29
Logo
7:30 am - 9:05 amISP-LHR
20h 35m2 stops
Logo
9:50 am - 7:45 pmLHR-ISP
14h 55m2 stops
$1,065
Find Deal
Thu, Oct 16 - Wed, Oct 22
Logo
9:59 am - 6:30 amISP-LHR
15h 31m1 stop
Logo
6:00 am - 7:45 pmLHR-ISP
18h 45m2 stops
$1,718
Find Deal
Thu, Oct 16 - Wed, Oct 22
Logo
9:59 am - 6:30 amISP-LHR
15h 31m1 stop
Logo
8:25 am - 4:15 pmLHR-ISP
12h 50m1 stop
$1,979
Find Deal
Thu, Oct 16 - Wed, Oct 22
Logo
4:33 pm - 6:55 amISP-LHR
10h 22m1 stop
Logo
9:50 am - 10:37 amLHR-ISP
29h 47m2 stops
$2,134
Find Deal
Tue, Oct 28 - Tue, Nov 4
Logo
12:40 pm - 11:25 amISP-LHR
17h 45m2 stops
Logo
9:20 am - 4:15 pmLHR-ISP
11h 55m1 stop
$2,556
Find Deal
Thu, Nov 13 - Sun, Nov 23
Logo
7:30 am - 8:25 amISP-LHR
19h 55m2 stops
Logo
6:00 pm - 11:04 amLHR-ISP
22h 04m2 stops
$6,215
Find Deal
Fri, Nov 21 - Fri, Nov 28

momondo Fare Finder

 
Customize your flight search to find flights from Islip 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 September 15, 2025.
Use the filters below to find and compare flights from Islip to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Wed 10/22

11:35 am-8:45 pm

2 stops28h 10m

London Heathrow

Wed 10/29

7:25 am-1:02 pm

2 stops33h 37m

$950

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Thu 10/16

7:30 am-9:05 am

2 stops20h 35m

London Heathrow

Wed 10/22

9:50 am-7:45 pm

2 stops14h 55m

$1,065

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Thu 10/16

9:59 am-6:30 am

1 stop15h 31m

London Heathrow

Wed 10/22

6:00 am-7:45 pm

2 stops18h 45m

$1,718

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Thu 10/16

9:59 am-6:30 am

1 stop15h 31m

London Heathrow

Wed 10/22

8:25 am-4:15 pm

1 stop12h 50m

$1,979

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Tue 10/28

4:33 pm-6:55 am

1 stop10h 22m

London Heathrow

Tue 11/4

9:50 am-10:37 am

2 stops29h 47m

$2,134

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Thu 11/13

12:40 pm-11:25 am

2 stops17h 45m

London Heathrow

Sun 11/23

9:20 am-4:15 pm

1 stop11h 55m

$2,556

IslipLondon

ISP - LHR

ISPLHR

Islip Long Island

Fri 11/21

7:30 am-8:25 am

2 stops19h 55m

London Heathrow

Fri 11/28

6:00 pm-11:04 am

2 stops22h 04m

$6,215

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to London from

How to get the cheapest flight ticket from Islip 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 $633. The most expensive day to fly to London Heathrow Airport is Sunday, with ticket prices averaging around $675.

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 in the morning. momondo users have found flights departing from Islip to London Heathrow Airport in the morning for as low as $581. 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 $691.

When to book flights from Islip to London Heathrow Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Islip 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 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 to London Heathrow Airport

Direct flights

None
There are no direct flights from Islip to London Heathrow Airport. There are no popular flight routes from Islip 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 10h 22m 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
Dover
Luton
Slough
Milton Keynes
Hayes
Guildford
Dartford
Crawley
Stansted
Chelmsford
Salisbury
Brentwood
Ilford
Folkestone
Colchester
Swindon
Stratford-upon-Avon
Watford

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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Wed 10/15
Wed 10/22
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