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$108+ Cheap flights from Philadelphia to Islip (PHL - ISP)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/14. Fares are subject to change and may not be available on all flights or dates of travel.
PHL — ISP
Oct 17 — Oct 241
Fri 10/17
Fri 10/24
1 adult, Economy
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Cheap flight deals from Philadelphia to Islip

Discover tips and strategies to find the most affordable flight options for your journey from Philadelphia (PHL) to Islip (ISP). 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 17, 2025.

Round-trip from

$188
(Frontier)

One-way from

$108
(Trip.com)

Popular in

November

Cheapest in

August

Average price

$263
From Philadelphia to Islip Long Island
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One-way flight from Philadelphia to Islip Long Island
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Highest demand for flights based on searches. 20% potential increase in price ($94 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($10 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 Philadelphia to Islip

Cheapest flights from Philadelphia to Islip
Explore the most affordable flight options available from Philadelphia to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 17, 2025.

This Frontier deal was found by Cheapflights users on 9/15. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/2210:16 pmPHL - ISP
1 stop12h 24mFrontier
Mon 9/295:05 pmISP - PHL
1 stop7h 47mFrontier
Deal found 9/15$188
This Frontier deal was found by Cheapflights users on 9/15. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/179:53 pmPHL - ISP
1 stop12h 44mFrontier
Mon 10/209:49 amISP - PHL
1 stop12h 50mFrontier
Deal found 9/15$198
This Kiwi.com deal was found by Cheapflights users on 9/16. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/141:58 pmPHL - ISP
1 stop20h 59mMultiple Airlines
Tue 10/219:37 pmISP - PHL
1 stop15h 16mMultiple Airlines
Deal found 9/16$229
This Kiwi.com deal was found by Cheapflights users on 9/16. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/118:32 amPHL - ISP
1 stop11h 33mMultiple Airlines
Tue 10/149:37 pmISP - PHL
1 stop23h 47mMultiple Airlines
Deal found 9/16$245
This Kiwi.com deal was found by Cheapflights users on 9/16. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/168:08 pmPHL - ISP
1 stop14h 29mMultiple Airlines
Thu 10/239:37 pmISP - PHL
1 stop9h 53mMultiple Airlines
Deal found 9/16$258
This Frontier deal was found by Cheapflights users on 9/14. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/198:00 amPHL - ISP
1 stop8h 27mFrontier
Sat 9/2011:40 amISP - PHL
1 stop7h 57mFrontier
Deal found 9/14$261
This Frontier deal was found by Cheapflights users on 9/15. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/2610:16 pmPHL - ISP
1 stop12h 39mFrontier
Sun 9/289:49 amISP - PHL
1 stop8h 14mFrontier
Deal found 9/15$270
This Kiwi.com deal was found by Cheapflights users on 9/15. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/910:32 pmPHL - ISP
1 stop12h 05mFrontier
Mon 11/108:02 pmISP - PHL
1 stop14h 28mFrontier
Deal found 9/15$284
This Kiwi.com deal was found by Cheapflights users on 9/15. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/2210:16 pmPHL - ISP
1 stop12h 24mMultiple Airlines
Mon 9/298:47 pmISP - PHL
2 stops24h 24mMultiple Airlines
Deal found 9/15$321

Cheapflights Fare Finder

 
Customize your flight search to find flights from Philadelphia to Islip 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 17, 2025.
Use the filters below to find and compare flights from Philadelphia to Islip that are best for you.

Fly from

Philadelphia

Fly to

Islip

Route

Depart

Return

Price

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Mon 9/22

10:16 pm-10:40 am

1 stop12h 24m

Islip Long Island

Mon 9/29

5:05 pm-12:52 am

1 stop7h 47m

$188

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Fri 10/17

9:53 pm-10:37 am

1 stop12h 44m

Islip Long Island

Mon 10/20

9:49 am-10:39 pm

1 stop12h 50m

$198

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Tue 10/14

1:58 pm-10:57 am

1 stop20h 59m

Islip Long Island

Tue 10/21

9:37 pm-12:53 pm

1 stop15h 16m

$229

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Thu 10/16

8:08 pm-10:37 am

1 stop14h 29m

Islip Long Island

Thu 10/23

11:40 am-7:30 am

2 stops19h 50m

$245

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Sat 10/11

8:32 am-8:05 pm

1 stop11h 33m

Islip Long Island

Tue 10/14

9:37 pm-9:24 pm

1 stop23h 47m

$245

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Fri 9/26

10:16 pm-10:55 am

1 stop12h 39m

Islip Long Island

Sun 9/28

9:49 am-6:03 pm

1 stop8h 14m

$270

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Sun 11/9

10:32 pm-10:37 am

1 stop12h 05m

Islip Long Island

Mon 11/10

8:02 pm-10:30 am

1 stop14h 28m

$284

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Tue 10/14

1:58 pm-10:57 am

1 stop20h 59m

$108

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Sat 10/4

3:55 pm-1:45 pm

2 stops45h 50m

$175

PhiladelphiaIslip

PHL - ISP

PHLISP

Philadelphia

Sun 11/9

7:00 am-3:30 pm

1 stop8h 30m

$353

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/16

Best time to book a flight from Philadelphia to Islip

Have a flexible travel schedule? Discover the best time to fly to Islip from Philadelphia 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 Philadelphia to Islip

What is the cheapest month to book a flight from Philadelphia to Islip?

Currently, January is the cheapest month in which you can book a flight from Philadelphia to Islip (average of $108). Flying from Philadelphia to Islip in November is currently the most expensive (average of $213). 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.

What is the cheapest time of day to fly from PHL to ISP?

Find hourly flight availability from Philadelphia to Islip. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 17, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Philadelphia to Islip as you normally would.

Related info for your journey

Find useful and relevant information for your journey from Philadelphia to Islip. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Philadelphia to Islip?

    There are many flights that can get you from Philadelphia to Islip in 12h 24m. Fly via Frontier to get the fastest option. There are 129 mi between Philadelphia and Islip.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Philadelphia to Islip 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 Philadelphia to Islip?

    Currently, January is the cheapest month in which you can book a flight from Philadelphia to Islip (average of $108). Flying from Philadelphia to Islip in November is currently the most expensive (average of $213). 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 Islip?

Book flights to Islip if you plan to visit one of these locations
Riverhead
Southampton

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Alternative routes for Philadelphia to Islip

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