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$418+ Cheap flights from Islip to Knoxville (ISP - TYS)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/1. Fares are subject to change and may not be available on all flights or dates of travel.
ISP — TYS
Oct 16 — Oct 231
Thu 10/16
Thu 10/23
1 adult, Economy
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Cheap flight deals from Islip to Knoxville

Discover tips and strategies to find the most affordable flight options for your journey from Islip (ISP) to Knoxville (TYS). 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 September 16, 2025.

Round-trip from

$418
(Kiwi.com)

Popular in

November

Cheapest in

January

Average price

$326
From Islip Long Island to Knoxville McGhee Tyson
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Highest demand for flights based on searches. 12% potential increase in price ($44 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Islip to Knoxville

Cheapest flights from Islip to Knoxville
Explore the most affordable flight options available from Islip to Knoxville. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 16, 2025.

This Frontier deal was found by Cheapflights users on 9/16. 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 10/169:37 pmISP - TYS
2 stops21h 55mFrontier
Mon 10/208:17 pmTYS - ISP
2 stops13h 27mFrontier
Deal found 9/16$474
This Kiwi.com deal was found by Cheapflights users on 9/14. 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.
Fri 10/104:58 pmISP - TYS
1 stop6h 38mMultiple Airlines
Mon 10/135:26 pmTYS - ISP
2 stops27h 16mMultiple Airlines
Deal found 9/14$533
This Kiwi.com deal was found by Cheapflights users on 9/14. 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.
Fri 11/72:25 pmISP - TYS
2 stops19h 39mMultiple Airlines
Mon 11/109:45 amTYS - ISP
1 stop9h 21mMultiple Airlines
Deal found 9/14$536
This Kiwi.com deal was found by Cheapflights users on 9/15. 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 10/129:47 pmISP - TYS
1 stop15h 16mMultiple Airlines
Sun 10/199:01 pmTYS - ISP
2 stops23h 06mMultiple Airlines
Deal found 9/15$574
This Frontier deal was found by Cheapflights users on 9/14. 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 10/99:37 pmISP - TYS
2 stops21h 55mFrontier
Mon 10/138:17 pmTYS - ISP
2 stops13h 27mFrontier
Deal found 9/14$777
This Kiwi.com deal was found by Cheapflights users on 9/14. 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 9/187:30 amISP - TYS
1 stop6h 59mMultiple Airlines
Sat 9/204:31 pmTYS - ISP
2 stops42h 09mMultiple Airlines
Deal found 9/14$840
This Kiwi.com deal was found by Cheapflights users on 9/14. 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.
Fri 9/195:05 pmISP - TYS
2 stops22h 36mMultiple Airlines
Tue 9/237:30 amTYS - ISP
1 stop5h 54mMultiple Airlines
Deal found 9/14$863
This Kiwi.com deal was found by Cheapflights users on 9/15. 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.
Fri 9/195:05 pmISP - TYS
2 stops22h 36mMultiple Airlines
Sun 9/219:00 amTYS - ISP
1 stop6h 21mMultiple Airlines
Deal found 9/15$1,158

Cheapflights Fare Finder

 
Customize your flight search to find flights from Islip to Knoxville 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 September 16, 2025.
Use the filters below to find and compare flights from Islip to Knoxville that are best for you.

Fly from

Islip

Fly to

Knoxville

Route

Depart

Return

Price

IslipKnoxville

ISP - TYS

ISPTYS

Islip Long Island

Wed 10/1

11:35 am-7:24 pm

1 stop7h 49m

Knoxville McGhee Tyson

Sun 10/5

1:18 pm-1:45 pm

2 stops24h 27m

$418

IslipKnoxville

ISP - TYS

ISPTYS

Islip Long Island

Thu 10/16

9:37 pm-7:32 pm

2 stops21h 55m

Knoxville McGhee Tyson

Mon 10/20

8:17 pm-9:44 am

2 stops13h 27m

$474

IslipKnoxville

ISP - TYS

ISPTYS

Islip Long Island

Fri 10/10

4:58 pm-11:36 pm

1 stop6h 38m

Knoxville McGhee Tyson

Mon 10/13

5:26 pm-8:42 pm

2 stops27h 16m

$533

IslipKnoxville

ISP - TYS

ISPTYS

Islip Long Island

Fri 11/7

2:25 pm-10:04 am

2 stops19h 39m

Knoxville McGhee Tyson

Mon 11/10

9:45 am-7:06 pm

1 stop9h 21m

$536

IslipKnoxville

ISP - TYS

ISPTYS

Islip Long Island

Sun 10/12

9:47 pm-1:03 pm

1 stop15h 16m

Knoxville McGhee Tyson

Sun 10/19

9:01 pm-8:07 pm

2 stops23h 06m

$574

IslipKnoxville

ISP - TYS

ISPTYS

Islip Long Island

Thu 10/9

9:37 pm-7:32 pm

2 stops21h 55m

Knoxville McGhee Tyson

Mon 10/13

8:17 pm-9:44 am

2 stops13h 27m

$777

IslipKnoxville

ISP - TYS

ISPTYS

Islip Long Island

Fri 9/19

5:05 pm-3:41 pm

2 stops22h 36m

Knoxville McGhee Tyson

Tue 9/23

7:30 am-1:24 pm

1 stop5h 54m

$863

IslipKnoxville

ISP - TYS

ISPTYS

Islip Long Island

Fri 9/19

5:05 pm-3:41 pm

2 stops22h 36m

Knoxville McGhee Tyson

Sun 9/21

9:00 am-3:21 pm

1 stop6h 21m

$1,158

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/16

Best time to book a flight from Islip to Knoxville

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

What is the cheapest month to book a flight from Islip to Knoxville?

Currently, January is the cheapest month in which you can book a flight from Islip to Knoxville (average of $295). Flying from Islip to Knoxville in March is currently the most expensive (average of $376). 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 Islip to Knoxville. 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 Islip to Knoxville?

    Frontier can get you from Islip to Knoxville in just under 21h 55m. Your travel time can differ by up to . Islip and Knoxville are separated by a distance of 682 mi.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Islip to Knoxville 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 Islip to Knoxville?

    Currently, January is the cheapest month in which you can book a flight from Islip to Knoxville (average of $295). Flying from Islip to Knoxville in March is currently the most expensive (average of $376). 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

Traveling to a place near Knoxville?

Book flights to Knoxville if you plan to visit one of these locations
Morristown
Cherokee
Corbin
Alcoa
Oak Ridge
Murphy

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