$125 Cheap Flights from Islip (ISP) to Denver (DEN)

View $125 flight on Mon, May 19, 2025Opens in a new window

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Find available prices by choosing your travel dates.

Cheap Flights from Islip to Denver (ISP-DEN)

Prices were available within the past 7 days and start at $125 for one-way flights and $250 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Mon, May 19 - Wed, May 21
ISP
Islip
DEN
Denver
$250 Roundtrip, found 3 days ago
$250
Roundtrip
found 3 days ago
Select Frontier Airlines flight, departing Mon, May 19 from Islip to Denver, returning Wed, May 21, priced at $250 found 3 days ago
Frontier Airlines
Thu, May 1 - Sun, May 11
ISP
Islip
DEN
Denver
$270 Roundtrip, found 3 days ago
$270
Roundtrip
found 3 days ago
Select Frontier Airlines flight, departing Thu, May 1 from Islip to Denver, returning Sun, May 11, priced at $270 found 3 days ago
Frontier Airlines
Sun, May 11 - Mon, May 12
ISP
Islip
DEN
Denver
$280 Roundtrip, found 2 days ago
$280
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Sun, May 11 from Islip to Denver, returning Mon, May 12, priced at $280 found 2 days ago
Frontier Airlines
Fri, May 2 - Mon, May 5
ISP
Islip
DEN
Denver
$290 Roundtrip, found 2 hours ago
$290
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Fri, May 2 from Islip to Denver, returning Mon, May 5, priced at $290 found 2 hours ago
Frontier Airlines
Fri, Apr 25 - Sun, May 11
ISP
Islip
DEN
Denver
$300 Roundtrip, found 3 days ago
$300
Roundtrip
found 3 days ago
Select Frontier Airlines flight, departing Fri, Apr 25 from Islip to Denver, returning Sun, May 11, priced at $300 found 3 days ago
Frontier Airlines
Wed, May 28 - Sun, Jun 1
ISP
Islip
DEN
Denver
$310 Roundtrip, found 2 hours ago
$310
Roundtrip
found 2 hours ago
Select Frontier Airlines flight, departing Wed, May 28 from Islip to Denver, returning Sun, Jun 1, priced at $310 found 2 hours ago
Southwest Airlines
Wed, May 28 - Sun, Jun 1
ISP
Islip
DEN
Denver
$317 Roundtrip, found 2 hours ago
$317
Roundtrip
found 2 hours ago
Select Southwest Airlines flight, departing Wed, May 28 from Islip to Denver, returning Sun, Jun 1, priced at $317 found 2 hours ago
Frontier Airlines
Sun, May 11 - Thu, May 15
ISP
Islip
DEN
Denver
$318 Roundtrip, found 3 hours ago
$318
Roundtrip
found 3 hours ago
Select Frontier Airlines flight, departing Sun, May 11 from Islip to Denver, returning Thu, May 15, priced at $318 found 3 hours ago
Frontier Airlines
Mon, Apr 28 - Fri, May 2
ISP
Islip
DEN
Denver
$320 Roundtrip, found 9 hours ago
$320
Roundtrip
found 9 hours ago
Select Frontier Airlines flight, departing Mon, Apr 28 from Islip to Denver, returning Fri, May 2, priced at $320 found 9 hours ago
JetBlue Airways
Thu, May 8 - Mon, May 12
ISP
Islip
DEN
Denver
$329 Roundtrip, found 12 hours ago
$329
Roundtrip
found 12 hours ago
Select JetBlue Airways flight, departing Thu, May 8 from Islip to Denver, returning Mon, May 12, priced at $329 found 12 hours ago

Frequently asked questions

How much does a flight from MacArthur Airport (ISP) to Denver Intl. Airport (DEN) cost?
Discover the latest flight deals from ISP to DEN by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from ISP to DEN?
The cheapest flights from ISP to DEN are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from MacArthur Airport (ISP) to Denver Intl. Airport (DEN)?
There are no direct flights from Islip, NY (ISP-MacArthur) to Denver Intl. Airport (DEN). However, there are other airports that offer nonstop flights. Begin your journey at John F. Kennedy Intl. Airport (JFK) and head straight to Denver without layovers.
What is the cheapest airline that flies from ISP to DEN?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from ISP to DEN. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from MacArthur Airport (ISP) to Denver Intl. Airport (DEN)?
Direct flights from MacArthur Airport (ISP) to Denver Intl. Airport (DEN) aren’t available daily, so you’ll need to take a flight with a layover. Explore your options with our filter tool. Enter your dates and select either “1 Stop” or “2+ Stops.”
What day of the week has the most flights from ISP to DEN?
Friday is usually the busiest day for flights, while Tuesday is often the quietest.* Remember that flight schedules can vary based on a number of factors, including the time of year and carrier.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from MacArthur Airport (ISP) to Denver Intl. Airport (DEN)?
To arrive at Denver Intl. Airport (DEN) on schedule, opt for a flight that leaves from MacArthur Airport (ISP) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this hour.**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.
Is it cheaper to buy a plane ticket from MacArthur Airport (ISP) to Denver Intl. Airport (DEN) last-minute?
Holding off until right before your break to book a flight from ISP to DEN often results in higher prices. While you may find some last-minute discounts, there’s no guarantee. Keep your travel schedule open for the best chance of getting a bargain.
Is it cheaper to book an ISP to DEN flight and hotel package?
Compared with arranging flights and hotels separately, booking an ISP to DEN flight and hotel package with Expedia could result in significant savings. Better yet, managing everything in one place takes the hassle out of planning your trip. Just secure your flights and select from our extensive range of stays, then tailor your trip with other add-ons like tours, car rentals and activities.
Can I cancel or change the date of my flight from MacArthur Airport (ISP) to Denver Intl. Airport (DEN)?
Usually, it’s possible to cancel or reschedule your ISP to DEN flight. However, if it’s been more than 24 hours since booking, additional charges may apply. Refer to your airline’s policies in your itinerary to see what changes are allowed and whether any costs are involved. You’ll also find more details on our Customer Service portal.
*Available to One Key members.