$88 Cheap Flights from Washington (IAD) to Islip (ISP)

View $88 flight on Fri, Oct 24, 2025Opens in a new window

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

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Cheap Flights from Washington to Islip (IAD-ISP)

Prices were available within the past 7 days and start at $88 for one-way flights and $164 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Thu, Sep 25 - Thu, Oct 2
IAD
Washington
ISP
Islip
$164 Roundtrip, found 1 hour ago
$164
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Thu, Sep 25 from Washington to Islip, returning Thu, Oct 2, priced at $164 found 1 hour ago
Frontier Airlines
Thu, Sep 25 - Sun, Sep 28
IAD
Washington
ISP
Islip
$174 Roundtrip, found 4 days ago
$174
Roundtrip
found 4 days ago
Select Frontier Airlines flight, departing Thu, Sep 25 from Washington to Islip, returning Sun, Sep 28, priced at $174 found 4 days ago
Frontier Airlines
Sun, Oct 26 - Sun, Nov 2
IAD
Washington
ISP
Islip
$178 Roundtrip, found 7 hours ago
$178
Roundtrip
found 7 hours ago
Select Frontier Airlines flight, departing Sun, Oct 26 from Washington to Islip, returning Sun, Nov 2, priced at $178 found 7 hours ago
Frontier Airlines
Sat, Sep 27 - Sat, Oct 18
IAD
Washington
ISP
Islip
$192 Roundtrip, found 1 day ago
$192
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Sat, Sep 27 from Washington to Islip, returning Sat, Oct 18, priced at $192 found 1 day ago
Frontier Airlines
Fri, Oct 24 - Mon, Oct 27
IAD
Washington
ISP
Islip
$199 Roundtrip, found 7 hours ago
$199
Roundtrip
found 7 hours ago
Select Frontier Airlines flight, departing Fri, Oct 24 from Washington to Islip, returning Mon, Oct 27, priced at $199 found 7 hours ago
Frontier Airlines
Fri, Oct 10 - Mon, Oct 20
IAD
Washington
ISP
Islip
$209 Roundtrip, found 5 days ago
$209
Roundtrip
found 5 days ago
Select Frontier Airlines flight, departing Fri, Oct 10 from Washington to Islip, returning Mon, Oct 20, priced at $209 found 5 days ago
Frontier Airlines
Sat, Sep 20 - Thu, Sep 25
IAD
Washington
ISP
Islip
$213 Roundtrip, found 1 hour ago
$213
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Sat, Sep 20 from Washington to Islip, returning Thu, Sep 25, priced at $213 found 1 hour ago
Frontier Airlines
Thu, Sep 18 - Thu, Sep 25
IAD
Washington
ISP
Islip
$227 Roundtrip, found 1 hour ago
$227
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Thu, Sep 18 from Washington to Islip, returning Thu, Sep 25, priced at $227 found 1 hour ago
Frontier Airlines
Mon, Oct 27 - Sat, Nov 1
IAD
Washington
ISP
Islip
$234 Roundtrip, found 7 hours ago
$234
Roundtrip
found 7 hours ago
Select Frontier Airlines flight, departing Mon, Oct 27 from Washington to Islip, returning Sat, Nov 1, priced at $234 found 7 hours ago
Frontier Airlines
Mon, Oct 13 - Sat, Oct 25
IAD
Washington
ISP
Islip
$241 Roundtrip, found 7 hours ago
$241
Roundtrip
found 7 hours ago
Select Frontier Airlines flight, departing Mon, Oct 13 from Washington to Islip, returning Sat, Oct 25, priced at $241 found 7 hours ago

Frequently asked questions

How much does a flight from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP) cost?
Secure a cheap one-way flight from $88 or cheap return flight from $164 from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP)?
Planning your trip for September is a good way to save, as it's the cheapest month for flights between IAD and ISP. You'll often find the lowest prices during off-peak months.
What is the cheapest airline that flies from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP)?
Expedia's filter tool lets you easily compare airlines, flight times and baggage options all in one place. Select your preferences, then sort by "Price (lowest to highest)" to see which carrier offers the cheapest IAD to ISP flight.
How many flights per day from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP)?
You'll need to book a flight with a layover when traveling from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP). There are no daily direct flights on this route. However, just filter your search to include one or more stops to find the best option for your trip.
What day of the week has the most flights from IAD to ISP?
You'll usually find Tuesday the quietest day for flights, while Fridays are often the busiest.* However this can vary from season to season and during public holidays or peak travel times.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP)?
Select a flight from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP) that leaves before 3 PM to reduce the risk of cancellations and delays. Departures later than this have a 22% higher chance of being canceled, on average.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for Islip from Washington Dulles Intl. Airport (IAD)?
You can land at one of these Islip airports after your direct flight from Washington Dulles Intl. Airport (IAD):

  • LaGuardia Airport (LGA)
  • John F. Kennedy Intl. Airport (JFK)
  • Tweed - New Haven Regional Airport (HVN)

Is it cheaper to buy a plane ticket from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP) last-minute?
Last-minute fares from IAD to ISP are generally more expensive. To lock in the best prices, start looking for flights as soon as possible. That said, if you're flexible with your travel dates, you may score a cheap fare just before your departure.
Is it cheaper to book an IAD to ISP flight and hotel package?
You'll generally save money by booking an IAD to ISP flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it's easy to manage it all in one convenient place. Once you've selected your preferred flights and accommodations, consider other add-ons like activities, car rentals and tours.
Can I cancel or change the date of my flight from Washington Dulles Intl. Airport (IAD) to MacArthur Airport (ISP)?
If you reserved your IAD to ISP flight in 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 that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you want more information.

Travel information

Travel information

Origin airport
Washington Dulles Intl.
Destination airport
MacArthur
Airlines serving
Frontier Airlines
Roundtrip price
$164
Distance
263 mi

Book with confidence

Book with confidence

Washington to Islip Flights

The cheapest times to fly from Washington to Islip

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 Washington to Islip are during the month of September. You can find some of the cheapest flights from Washington to Islip with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Washington to Islip

Sunday is one of the best days to book for cheap flights from Washington to Islip: 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 Washington to Islip

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 Washington to Islip in 2025. You can also book with separate airlines for your outbound and return journeys, from $88 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 Washington to Islip 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 Washington to Islip 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.

 

Washington to Islip Flights

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*Available to One Key members.