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Islip

$82+ Cheap flights from Dulles Intl (IAD) to Islip (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 10/3. Fares are subject to change and may not be available on all flights or dates of travel.
IAD — ISP
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
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Cheap flight deals from Dulles Intl to Islip

Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) 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 11, 2025.

Round-trip from

$173
(Kiwi.com)

One-way from

$82
(Kiwi.com)

Popular in

December

Cheapest in

April

Average price

$177
From Washington, D.C. Dulles Intl to Islip Long Island
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One-way flight from Washington, D.C. Dulles Intl to Islip Long Island
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Highest demand for flights based on searches. 20% potential increase in price ($54 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($6 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 Dulles Intl to Islip

Cheapest flights from Dulles Intl to Islip
Explore the most affordable flight options available from Dulles Intl to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

This Kiwi.com deal was found by Cheapflights users on 9/9. 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.
Fri 9/267:14 pmIAD - ISP
1 stop15h 41mFrontier
Sun 9/289:49 amISP - IAD
1 stop11h 30mFrontier
Deal found 9/9$173
This Kiwi.com deal was found by Cheapflights users on 9/9. 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.
Fri 10/39:09 pmIAD - ISP
1 stop19h 14mFrontier
Sun 10/59:49 amISP - IAD
1 stop11h 35mFrontier
Deal found 9/9$227
This Kiwi.com deal was found by Cheapflights users on 9/9. 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 10/91:07 pmIAD - ISP
1 stop19h 57mFrontier
Thu 10/169:37 pmISP - IAD
2 stops25h 52mFrontier
Deal found 9/9$272
This Kiwi.com deal was found by Cheapflights users on 9/8. 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.
Fri 10/109:38 pmIAD - ISP
1 stop12h 59mFrontier
Mon 10/139:49 amISP - IAD
1 stop8h 56mFrontier
Deal found 9/8$273
This Frontier deal was found by Cheapflights users on 9/10. 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.
Thu 9/118:59 pmIAD - ISP
1 stop12h 05mFrontier
Sun 9/149:49 amISP - IAD
1 stop11h 30mFrontier
Deal found 9/10$276
This Frontier deal was found by Cheapflights users on 9/9. 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.
Tue 10/79:00 amIAD - ISP
2 stops11h 42mFrontier
Tue 10/1410:39 amISP - IAD
2 stops9h 07mFrontier
Deal found 9/9$308
This Frontier deal was found by Cheapflights users on 9/10. 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 10/315:34 pmIAD - ISP
2 stops17h 03mFrontier
Sun 11/28:49 amISP - IAD
2 stops15h 22mFrontier
Deal found 9/10$312
This Kiwi.com deal was found by Cheapflights users on 9/11. 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 11/188:40 amIAD - ISP
2 stops25h 57mMultiple Airlines
Sat 11/228:47 amISP - IAD
1 stop22h 58mMultiple Airlines
Deal found 9/11$316

Cheapflights Fare Finder

 
Customize your flight search to find flights from Dulles Intl 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 11, 2025.
Use the filters below to find and compare flights from Washington, D.C. Dulles Intl Airport to Islip that are best for you.

Fly from

Dulles Intl

Fly to

Islip

Route

Depart

Return

Price

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Fri 9/26

7:14 pm-10:55 am

1 stop15h 41m

Islip Long Island

Sun 9/28

9:49 am-9:19 pm

1 stop11h 30m

$173

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Thu 10/9

1:07 pm-9:04 am

1 stop19h 57m

Islip Long Island

Thu 10/16

9:37 pm-11:29 pm

2 stops25h 52m

$272

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Fri 10/10

9:38 pm-10:37 am

1 stop12h 59m

Islip Long Island

Mon 10/13

9:49 am-6:45 pm

1 stop8h 56m

$273

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Fri 10/3

7:14 pm-10:55 am

1 stop15h 41m

Islip Long Island

Sun 10/5

9:49 am-9:24 pm

1 stop11h 35m

$315

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Fri 10/31

5:34 pm-10:37 am

2 stops17h 03m

Islip Long Island

Sun 11/2

8:49 am-10:09 pm

1 stop13h 20m

$318

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Fri 9/26

7:14 pm-10:55 am

1 stop15h 41m

Islip Long Island

Tue 9/30

11:25 am-7:55 pm

2 stops32h 30m

$330

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Sat 10/11

4:22 pm-8:59 am

2 stops16h 37m

Islip Long Island

Tue 10/14

10:39 am-7:46 pm

2 stops9h 07m

$332

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Fri 11/7

5:34 pm-10:37 am

2 stops17h 03m

Islip Long Island

Sun 11/9

9:27 pm-4:34 pm

2 stops19h 07m

$334

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Fri 11/14

8:36 pm-10:37 am

1 stop14h 01m

Islip Long Island

Sun 11/16

8:49 am-10:09 pm

1 stop13h 20m

$348

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Thu 10/9

8:02 pm-10:37 am

1 stop14h 35m

Islip Long Island

Sun 10/12

9:47 pm-3:39 pm

2 stops17h 52m

$355

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/11

Showing 1-10 of 22 results
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Best time to book a flight from Dulles Intl to Islip

Have a flexible travel schedule? Discover the best time to fly to Islip from Dulles Intl 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 Washington, D.C. Dulles Intl Airport to Islip

What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to Islip?

Currently, January is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Islip (average of $108). Flying from Washington, D.C. Dulles Intl Airport 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.

Related info for your journey

Find useful and relevant information for your journey from Dulles Intl to Islip. 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 into for flights to Islip from Washington, D.C. Dulles Intl?

    Located just 7.2 mi from the city center, Islip Long Island is the airport most travelers will use when flying to Islip from Washington, D.C. Dulles Intl. Booking flights from Washington, D.C. Dulles Intl to Long Island (ISP) should be relatively easy as there are 0 daily inbound flights from Washington, D.C. Dulles Intl from 0 different airlines.

  • How long is the flight from Washington, D.C. Dulles Intl Airport to Islip?

    Frontier can get you from Washington, D.C. Dulles Intl Airport to Islip in just under 15h 41m. Your travel time can differ by up to . The distance between Washington, D.C. Dulles Intl Airport and Islip is about 263 mi.

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

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

  • How can I find direct flights from Dulles Intl to Islip?

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

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

    Yes. Cheapflights offers flight deals from Dulles Intl 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 Washington, D.C. Dulles Intl Airport to Islip?

    Currently, January is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Islip (average of $108). Flying from Washington, D.C. Dulles Intl Airport 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

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Alternative routes for Dulles Intl to Islip

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