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Islip

$90+ Cheap flights from Denver to Islip, NY (DEN - 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 4/22. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ISP
Feb 25 — Mar 41
Wed 2/25
Wed 3/4
1 adult, Economy
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Cheap flight deals from Denver to Islip

Cheapest flights from Denver to Islip
Explore the most affordable flight options available from Denver to Islip. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 26, 2026.

This CheapOair deal was found by Cheapflights users on 1/25. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/1111:59 pm
DEN
-
ISP
1 stop12h 40m
Frontier
Wed 2/182:03 pm
ISP
-
DEN
1 stop10h 56m
Frontier
Deal found 1/25$201
This Frontier deal was found by Cheapflights users on 1/25. 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.
Sat 1/316:32 pm
DEN
-
ISP
1 stop12h 08m
Frontier
Thu 2/57:43 pm
ISP
-
DEN
1 stop14h 47m
Frontier
Deal found 1/25$262
This Frontier deal was found by Cheapflights users on 1/25. 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 4/2311:59 pm
DEN
-
ISP
1 stop12h 56m
Frontier
Sun 4/264:07 pm
ISP
-
DEN
1 stop8h 52m
Frontier
Deal found 1/25$296
This Kiwi.com deal was found by Cheapflights users on 1/26. 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.
Sat 2/711:38 am
DEN
-
ISP
2 stops19h 02m
Multiple Airlines
Mon 2/92:31 pm
ISP
-
DEN
1 stop9h 18m
Multiple Airlines
Deal found 1/26$324
This Frontier deal was found by Cheapflights users on 1/25. 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.
Sat 1/316:32 pm
DEN
-
ISP
1 stop12h 08m
Frontier
Fri 2/69:43 pm
ISP
-
DEN
1 stop14h 17m
Frontier
Deal found 1/25$336
This Frontier deal was found by Cheapflights users on 1/25. 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 2/266:00 am
DEN
-
ISP
1 stop8h 22m
Frontier
Mon 3/23:34 pm
ISP
-
DEN
1 stop9h 25m
Frontier
Deal found 1/25$364
This Frontier deal was found by Cheapflights users on 1/25. 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 1/309:41 am
DEN
-
ISP
1 stop9h 06m
Frontier
Thu 2/57:43 pm
ISP
-
DEN
1 stop14h 47m
Frontier
Deal found 1/25$371
This CheapOair deal was found by Cheapflights users on 1/25. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/2511:59 pm
DEN
-
ISP
1 stop14h 14m
Frontier
Sun 3/295:08 pm
ISP
-
DEN
1 stop17h 12m
Frontier
Deal found 1/25$395
This Kiwi.com deal was found by Cheapflights users on 1/24. 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.
Sun 2/18:10 am
DEN
-
ISP
2 stops32h 38m
Frontier
Sun 2/87:53 pm
ISP
-
DEN
1 stop26h 07m
Frontier
Deal found 1/24$399
This Frontier deal was found by Cheapflights users on 1/25. 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 1/309:41 am
DEN
-
ISP
1 stop9h 06m
Frontier
Fri 2/69:43 pm
ISP
-
DEN
1 stop14h 17m
Frontier
Deal found 1/25$445
This Frontier deal was found by Cheapflights users on 1/25. 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.
Sat 1/316:32 pm
DEN
-
ISP
1 stop12h 08m
Frontier
Sun 2/89:25 am
ISP
-
DEN
1 stop8h 41m
Frontier
Deal found 1/25$481

Find flight deals from Denver to Islip

Discover tips and strategies to find the most affordable flight options for your journey from Denver (DEN) 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 January 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

Expedia
3 stars

Round-trip from

$201
(CheapOair)

One-way from

$90
(CheapOair)

Popular in

March

Cheapest in

January

Average price

$242
Provider with most accurate pricing for Denver Intl-Islip Long Island flight deals.
Search Deals
Provider most trusted by Cheapflights users for Denver Intl-Islip Long Island flights.
Search Deals
From Denver Intl to Islip Long Island
Search Deals
One-way flight from Denver Intl to Islip Long Island
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($15 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($3 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Denver 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 January 26, 2026.
Use the filters below to find and compare flights from Denver to Islip that are best for you.

Fly from

Denver

Fly to

Islip

Route

Depart

Return

Price

DenverIslip

DEN - ISP

DENISP

Denver Intl

Wed 2/11

11:59 pm-2:39 pm

1 stop12h 40m

Islip Long Island

Wed 2/18

2:03 pm-10:59 pm

1 stop10h 56m

$201

DenverIslip

DEN - ISP

DENISP

Denver Intl

Thu 4/23

11:59 pm-2:55 pm

1 stop12h 56m

Islip Long Island

Sun 4/26

4:07 pm-10:59 pm

1 stop8h 52m

$296

DenverIslip

DEN - ISP

DENISP

Denver Intl

Sat 2/7

11:38 am-8:40 am

2 stops19h 02m

Islip Long Island

Mon 2/9

2:31 pm-9:49 pm

1 stop9h 18m

$324

DenverIslip

DEN - ISP

DENISP

Denver Intl

Thu 2/26

6:00 am-4:22 pm

1 stop8h 22m

Islip Long Island

Mon 3/2

3:34 pm-10:59 pm

1 stop9h 25m

$364

DenverIslip

DEN - ISP

DENISP

Denver Intl

Wed 3/25

11:59 pm-4:13 pm

1 stop14h 14m

Islip Long Island

Sun 3/29

5:08 pm-8:20 am

1 stop17h 12m

$395

DenverIslip

DEN - ISP

DENISP

Denver Intl

Fri 6/26

7:00 am-5:15 pm

1 stop8h 15m

Islip Long Island

Fri 7/3

6:00 am-11:25 am

1 stop7h 25m

$487

DenverIslip

DEN - ISP

DENISP

Denver Intl

Wed 4/22

11:59 pm-9:13 am

1 stop7h 14m

$90

DenverIslip

DEN - ISP

DENISP

Denver Intl

Sat 2/28

7:00 am-4:12 pm

1 stop7h 12m

$90

DenverIslip

DEN - ISP

DENISP

Denver Intl

Thu 2/12

6:00 am-4:12 pm

1 stop8h 12m

$90

DenverIslip

DEN - ISP

DENISP

Denver Intl

Wed 2/25

11:59 pm-7:38 am

1 stop29h 39m

$96

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/24

Showing 1-10 of 17 results
1
2

Compare providers for flights from Denver 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 Denver to Islip in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star

*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 Denver-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 Denver-Islip, New York flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Denver-Islip, New York flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Denver-Islip, New York flights, Cheapflights users trust Expedia the most. Expedia 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 Denver-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 Denver to Islip

Have a flexible travel schedule? Discover the best time to fly to Islip from Denver 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 Denver to Islip

What is the cheapest month to book a flight from Denver to Islip, New York?

Currently, October is the cheapest month in which you can book a flight from Denver to Islip, New York (average of $65). Flying from Denver to Islip, New York in June is currently the most expensive (average of $169). 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.

Reviews of airlines servicing Islip

Get insights into the airlines that provide service to Islip. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Islip. Reviews last updated January 26, 2026.
Read reviews from past customers who have flown Southwest from Denver to Islip. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
Southwest
8.0
Very good
4,268 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Related info for your journey

Find useful and relevant information for your journey from Denver to Islip. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Denver to Islip, New York?

    There are many flights that can get you from Denver to Islip, New York in 12h 40m. Fly via Frontier to get the fastest option. Airlines will cover a distance of 1654 mi.

  • What is the cheapest airline to fly from Denver to Islip, New York round-trip?

    Southwest, at $357, was found to be the cheapest airline from Denver to Islip, New York..

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

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

  • How can I find direct flights from Denver to Islip?

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

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

    Yes. Cheapflights offers flight deals from Denver 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 Denver to Islip, New York?

    Currently, October is the cheapest month in which you can book a flight from Denver to Islip, New York (average of $65). Flying from Denver to Islip, New York in June is currently the most expensive (average of $169). 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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Top airline flying from Denver to Islip

Discover the top airline that operate flights from Denver to Islip. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated January 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
SouthwestCheapest$357Average$452FlexibilityNo cancel feeOn-time63%

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