$80 Cheap Flights from Islip (ISP) to Washington (IAD)

View $80 flight on Mon, Jun 8, 2026Opens in a new window

Popular airlines from MacArthur Airport (ISP) to Washington Dulles Intl. Airport (IAD)

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Cheap Flights from Islip to Washington (ISP-IAD)

Prices were available within the past 7 days and start at $80 for one-way flights and $170 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Wed, May 27 - Tue, Jun 2
ISP
Islip
IAD
Washington
$170 Roundtrip, found 4 days ago
$170
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Wed, May 27 from Islip to Washington, returning Tue, Jun 2, priced at $170 found 4 days ago
Frontier Airlines
Wed, May 27 - Wed, Jun 17
ISP
Islip
IAD
Washington
$185 Roundtrip, found 4 days ago
$185
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Wed, May 27 from Islip to Washington, returning Wed, Jun 17, priced at $185 found 4 days ago
Frontier Airlines
Fri, Apr 17 - Sun, Apr 19
ISP
Islip
IAD
Washington
$191 Roundtrip, found 10 hours ago
$191
Roundtrip
found 10 hours ago
Select Frontier Airlines flight, departing Fri, Apr 17 from Islip to Washington, returning Sun, Apr 19, priced at $191 found 10 hours ago
Frontier Airlines
Tue, Aug 11 - Wed, Aug 26
ISP
Islip
IAD
Washington
$200 Roundtrip, found 5 days ago
$200
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Tue, Aug 11 from Islip to Washington, returning Wed, Aug 26, priced at $200 found 5 days ago
Frontier Airlines
Wed, May 27 - Wed, Jun 10
ISP
Islip
IAD
Washington
$205 Roundtrip, found 4 days ago
$205
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Wed, May 27 from Islip to Washington, returning Wed, Jun 10, priced at $205 found 4 days ago
Frontier Airlines
Thu, May 28 - Wed, Jun 17
ISP
Islip
IAD
Washington
$206 Roundtrip, found 4 days ago
$206
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Thu, May 28 from Islip to Washington, returning Wed, Jun 17, priced at $206 found 4 days ago
Frontier Airlines
Thu, May 28 - Sun, May 31
ISP
Islip
IAD
Washington
$212 Roundtrip, found 4 days ago
$212
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Thu, May 28 from Islip to Washington, returning Sun, May 31, priced at $212 found 4 days ago
Frontier Airlines
Thu, Aug 6 - Wed, Aug 26
ISP
Islip
IAD
Washington
$214 Roundtrip, found 5 days ago
$214
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Thu, Aug 6 from Islip to Washington, returning Wed, Aug 26, priced at $214 found 5 days ago
Frontier Airlines
Wed, Jul 22 - Tue, Aug 11
ISP
Islip
IAD
Washington
$220 Roundtrip, found 5 days ago
$220
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Wed, Jul 22 from Islip to Washington, returning Tue, Aug 11, priced at $220 found 5 days ago
Frontier Airlines
Wed, May 27 - Mon, Jun 1
ISP
Islip
IAD
Washington
$225 Roundtrip, found 3 days ago
$225
Roundtrip
found 3 days ago
Select Frontier Airlines flight, departing Wed, May 27 from Islip to Washington, returning Mon, Jun 1, priced at $225 found 3 days ago

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Frequently asked questions

How much does a flight from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.) cost?
You can find cheap one-way flights from $80 and cheap return flights from $170 ISP to IAD with Expedia. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see our cheapest fares first, and use the Price Tracking tool to receive alerts when ISP to IAD ticket fares go up or down.
What is the cheapest month to fly from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
The cheapest month to fly from ISP to IAD is May when demand is low. Traveling in off-peak or shoulder months is usually a good way to secure cheap tickets, just remember to avoid flying during holidays if you're able to. Use the calendar view in your search to see which months have low fares on this route.
Which airlines fly direct from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
Enter ISP to IAD and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
What is the cheapest airline that flies from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
Frontier Airlines is the carrier that flies from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.). Use Expedia's flight search tool to compare airlines on this route and find our cheapest option for your trip. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
To find a cheap flight from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best time to fly from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
The best time to fly is usually mid-week (Tuesday or Wednesday) and during early morning hours as flights tend to be cheaper, less crowded, and generally more on-time. Avoid major holidays and peak vacation seasons for smoother travel. Combining off-peak days and hours often gives the best combination of cost, comfort, and convenience.
What is the earliest flight from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
Sort flights by "Departure (earliest)" on Expedia to find the earliest flight from ISP to IAD. To compare more early flights, use the "Early Morning" and "Morning" filters in your search.
How long does it take to fly from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
A flight from ISP to IAD with a layover takes around 8 hours 50 minutes, with the route covering approximately 263 miles. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
Select the "Business class" and "First class" filters when looking for ISP to IAD flights on Expedia. This is the easiest way to compare prices, routes and flight times for your trip.
How do I earn miles on a Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.) flight with Expedia?
It's easy to earn miles on a Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for Washington from MacArthur (ISP)?
If you're planning to travel to Washington from MacArthur (ISP), you can fly into Ronald Reagan Washington National (DCA) Some flights may connect through major hubs like Orlando Intl. (MCO), Baltimore Washington Intl. Thurgood Marshall (BWI), Logan Intl. (BOS) before reaching Washington. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.) at the last minute?
Typically, booking a last minute flight from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.) flight and hotel package?
Securing a Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.) Fairfax County Vacation Packages is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.)?
If you booked your Islip, NY (ISP-MacArthur) to Washington, DC (IAD-Washington Dulles Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
MacArthur
Destination airport
Washington Dulles Intl.
Airlines serving
Frontier Airlines
Roundtrip price
$170
Distance
263 mi

Book with confidence

Islip to Washington Flights

The cheapest times to fly from Islip to Washington

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Islip to Washington are during the month of May. You can find some of the cheapest flights from Islip to Washington with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Islip to Washington

Sunday is one of the best days to book for cheap flights from Islip to Washington: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Islip to Washington

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Islip to Washington in 2026. You can also book with separate airlines for your outbound and return journeys, from $80 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Islip to Washington flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Islip to Washington airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Islip to Washington Flights

*Flight schedules are subject to change.

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*Available to One Key members.