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Islip

$121+ Cheap flights from Dulles Intl (IAD) to Islip, NY (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 4/6. Fares are subject to change and may not be available on all flights or dates of travel.
IAD — ISP
Apr 13 — Apr 201
Mon 4/13
Mon 4/20
1 adult, Economy
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Cheap 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 March 14, 2026.

This Expedia deal was found by Cheapflights users on 3/13. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/17:27 pm
IAD
-
ISP
1 stop21h 50m
Frontier
Thu 6/411:00 am
ISP
-
IAD
1 stop7h 42m
Frontier
Deal found 3/13$256
This Booking.com deal was found by Cheapflights users on 3/13. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/24:01 pm
IAD
-
ISP
1 stop18h 04m
Frontier
Fri 6/511:00 am
ISP
-
IAD
1 stop7h 42m
Frontier
Deal found 3/13$288
This Gotogate deal was found by Cheapflights users on 3/12. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/47:27 pm
IAD
-
ISP
1 stop14h 38m
Frontier
Sun 6/711:00 am
ISP
-
IAD
1 stop7h 42m
Frontier
Deal found 3/12$319
This Kiwi.com deal was found by Cheapflights users on 3/9. 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 5/148:09 am
IAD
-
ISP
2 stops11h 04m
Multiple Airlines
Sun 5/174:07 pm
ISP
-
IAD
1 stop15h 20m
Multiple Airlines
Deal found 3/9$329
This Kiwi.com deal was found by Cheapflights users on 3/13. 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.
Wed 6/245:27 pm
IAD
-
ISP
1 stop15h 41m
Multiple Airlines
Tue 6/305:27 pm
ISP
-
IAD
2 stops43h 53m
Multiple Airlines
Deal found 3/13$333
This Kiwi.com deal was found by Cheapflights users on 3/11. 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.
Mon 4/68:34 am
IAD
-
ISP
1 stop15h 49m
Frontier
Wed 4/85:28 pm
ISP
-
IAD
1 stop18h 05m
Frontier
Deal found 3/11$368
This Kiwi.com deal was found by Cheapflights users on 3/11. 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.
Mon 4/68:34 am
IAD
-
ISP
1 stop15h 49m
Multiple Airlines
Wed 4/811:50 am
ISP
-
IAD
2 stops12h 46m
Multiple Airlines
Deal found 3/11$394
This Kiwi.com deal was found by Cheapflights users on 3/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/256:20 am
IAD
-
ISP
2 stops33h 53m
Frontier
Sun 3/295:08 pm
ISP
-
IAD
1 stop14h 16m
Frontier
Deal found 3/10$399
This Kiwi.com deal was found by Cheapflights users on 3/12. 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 6/47:27 pm
IAD
-
ISP
1 stop14h 38m
Multiple Airlines
Sun 6/75:50 pm
ISP
-
IAD
2 stops17h 49m
Multiple Airlines
Deal found 3/12$403
This Kiwi.com deal was found by Cheapflights users on 3/9. 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 3/198:15 am
IAD
-
ISP
1 stop7h 34m
Frontier
Fri 3/201:42 pm
ISP
-
IAD
1 stop17h 42m
Frontier
Deal found 3/9$410
This Kiwi.com deal was found by Cheapflights users on 3/9. 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 3/198:15 am
IAD
-
ISP
1 stop7h 34m
Multiple Airlines
Fri 3/202:31 pm
ISP
-
IAD
2 stops16h 53m
Multiple Airlines
Deal found 3/9$431

Find 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 March 14, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$256
(Expedia)

One-way from

$121
(Orbitz)

Popular in

March

Cheapest in

April

Average price

$267
Provider with most accurate pricing for Washington, D.C. Dulles Intl-Islip Long Island flight deals.
Search Deals
Provider most trusted by Cheapflights users for Washington, D.C. Dulles Intl-Islip Long Island flights.
Search Deals
From Washington, D.C. Dulles Intl to Islip Long Island
Search Deals
One-way flight from Washington, D.C. Dulles Intl to Islip Long Island
Search Deals
Highest demand for flights based on searches. 4% potential increase in price ($8 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($7 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals

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 March 14, 2026.
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

Fly to

Route

Depart

Return

Price

Cheapest round-trip

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Mon 6/1

7:27 pm-5:17 pm

1 stop21h 50m

Islip Long Island

Thu 6/4

11:00 am-6:42 pm

1 stop7h 42m

$256

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Tue 6/2

4:01 pm-10:05 am

1 stop18h 04m

Islip Long Island

Fri 6/5

11:00 am-6:42 pm

1 stop7h 42m

$288

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Thu 5/14

8:09 am-7:13 pm

2 stops11h 04m

Islip Long Island

Sun 5/17

4:07 pm-7:27 am

1 stop15h 20m

$329

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Mon 4/6

8:34 am-12:23 am

1 stop15h 49m

Islip Long Island

Wed 4/8

11:50 am-12:36 am

2 stops12h 46m

$394

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Thu 6/4

7:27 pm-10:05 am

1 stop14h 38m

Islip Long Island

Sun 6/7

5:50 pm-11:39 am

2 stops17h 49m

$403

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Thu 3/19

8:15 am-3:49 pm

1 stop7h 34m

Islip Long Island

Fri 3/20

1:42 pm-7:24 am

1 stop17h 42m

$410
Quickest round-trip

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Thu 3/19

8:15 am-3:49 pm

1 stop7h 34m

Islip Long Island

Fri 3/20

2:31 pm-7:24 am

2 stops16h 53m

$431

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Thu 4/9

4:01 pm-7:11 pm

1 stop27h 10m

Islip Long Island

Thu 4/16

8:31 pm-9:54 am

2 stops37h 23m

$434

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Wed 6/3

5:07 pm-10:05 am

1 stop16h 58m

Islip Long Island

Fri 6/5

11:00 am-6:42 pm

1 stop7h 42m

$455

Washington, D.C.Islip

IAD - ISP

IADISP

Washington, D.C. Dulles Intl

Sat 4/18

10:51 am-9:13 am

2 stops22h 22m

Islip Long Island

Sun 4/19

12:00 pm-8:06 pm

1 stop8h 06m

$493

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/11

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

Compare providers for flights from Dulles Intl to Islip

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Dulles Intl to Islip in March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Islip, New York flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Washington, D.C. Dulles Intl Airport-Islip, New York flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Islip, New York flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Islip, New York flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Dulles Intl Airport-Islip, New York flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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, New York?

Currently, April is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Islip, New York (average of $67). Flying from Washington, D.C. Dulles Intl Airport to Islip, New York in July is currently the most expensive (average of $138). 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, New York?

    There are many flights that can get you from Washington, D.C. Dulles Intl Airport to Islip, New York in 21h 50m. Fly via Frontier to get the fastest option. Airlines will cover a distance of 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, New York?

    Currently, April is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Islip, New York (average of $67). Flying from Washington, D.C. Dulles Intl Airport to Islip, New York in July is currently the most expensive (average of $138). 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.

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