We've gone through lots of different flights, to help you find the cheapest way to get from London Heathrow to Islip. You can choose from zero airlines.
If you want to broaden your search, look at flights departing from other airports.
The distance between London Heathrow to Islip is 5488 km. You can see the various flight times in the results.
Searching by month, for instance, will show you the best time of the week to fly.