$275+ Cheap flights from Islip, NY 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 12/7. Fares are subject to change and may not be available on all flights or dates of travel.
ISP — TYS
Oct 16 — Oct 231
Round-trip
1 adult, Economy
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Find cheap flights from Islip to Knoxville with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Islip to Knoxville
Cheapest
Best
Last-minute
Cheapest flights from Islip to KnoxvilleExplore 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, 2026.
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, 2026.
This Southwest deal was found by Cheapflights users on 9/13. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/76:30 am -
1 stop10h 10m
Sat 12/128:15 am -
1 stop6h 40m
Deal found 9/13![Southwest logo]()
$275
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/66:05 am -
2 stops10h 35m
Tue 10/131:00 pm -
2 stops7h 00m
Deal found 9/14![Southwest logo]()
$437
This Kiwi.com deal was found by Cheapflights users on 9/11. 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 9/2612:00 pm -
2 stops28h 48m
Wed 9/3010:28 am -
1 stop6h 30m
Deal found 9/11![Multiple Airlines logo]()
$453
This Southwest deal was found by Cheapflights users on 9/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/1912:50 pm -
1 stop8h 45m
Mon 12/218:00 am -
1 stop8h 20m
Deal found 9/11![Southwest logo]()
$460
This Southwest deal was found by Cheapflights users on 9/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/262:00 pm -
1 stop6h 40m
Wed 9/308:05 am -
1 stop4h 05m
Deal found 9/11![Southwest logo]()
$467
This Kiwi.com deal was found by Cheapflights users on 9/11. 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 9/255:43 pm -
1 stop18h 19m
Mon 9/2812:22 pm -
1 stop28h 36m
Deal found 9/11![Multiple Airlines logo]()
$471
Best flights from Islip to KnoxvilleDiscover carefully curated flight deals from Islip to Knoxville that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 16, 2026.
Discover carefully curated flight deals from Islip to Knoxville that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 16, 2026.
This Southwest deal was found by Cheapflights users on 9/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/1912:50 pm -
1 stop8h 45m
Mon 12/218:00 am -
1 stop8h 20m
Deal found 9/11![Southwest logo]()
$460
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.
Thu 10/226:25 pm -
1 stop17h 49m
Sun 10/257:00 am -
1 stop10h 30m
Deal found 9/15![Multiple Airlines logo]()
$510
This Southwest deal was found by Cheapflights users on 9/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/262:00 pm -
1 stop6h 40m
Wed 9/308:05 am -
1 stop4h 05m
Deal found 9/11![Southwest logo]()
$467
This Southwest deal was found by Cheapflights users on 9/13. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/612:25 pm -
1 stop9h 20m
Mon 11/912:50 pm -
2 stops10h 45m
Deal found 9/13![Southwest logo]()
$488
This Southwest deal was found by Cheapflights users on 9/12. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1012:20 pm -
1 stop7h 20m
Sat 10/178:10 am -
1 stop3h 45m
Deal found 9/12![Southwest logo]()
$508
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/23:10 pm -
1 stop6h 20m
Mon 10/512:50 pm -
1 stop10h 25m
Deal found 9/15![Southwest logo]()
$588
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/254:55 pm -
1 stop4h 50m
Sat 11/288:55 am -
1 stop7h 30m
Deal found 9/14![Southwest logo]()
$667
This Southwest deal was found by Cheapflights users on 9/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/93:10 pm -
1 stop6h 25m
Fri 10/168:20 am -
1 stop6h 10m
Deal found 9/11![Southwest logo]()
$684
Last-minute flights from Islip to KnoxvilleDiscover last-minute flight deals from Islip to Knoxville. Data last updated September 16, 2026 and is based on user searches.
Discover last-minute flight deals from Islip to Knoxville. Data last updated September 16, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 9/11. 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 9/255:43 pm -
1 stop18h 19m
Mon 9/2812:22 pm -
1 stop28h 36m
Deal found 9/11![Multiple Airlines logo]()
$471
This Kiwi.com deal was found by Cheapflights users on 9/11. 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 9/2612:00 pm -
2 stops28h 48m
Wed 9/3010:28 am -
1 stop6h 30m
Deal found 9/11![Multiple Airlines logo]()
$453
This Southwest deal was found by Cheapflights users on 9/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/262:00 pm -
1 stop6h 40m
Wed 9/308:05 am -
1 stop4h 05m
Deal found 9/11![Southwest logo]()
$467
This Southwest 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/66:05 am -
2 stops10h 35m
Tue 10/131:00 pm -
2 stops7h 00m
Deal found 9/14![Southwest logo]()
$437
This Southwest deal was found by Cheapflights users on 9/12. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1012:20 pm -
1 stop7h 20m
Sat 10/178:10 am -
1 stop3h 45m
Deal found 9/12![Southwest logo]()
$508
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.
Thu 10/226:25 pm -
1 stop17h 49m
Sun 10/257:00 am -
1 stop10h 30m
Deal found 9/15![Multiple Airlines logo]()
$510
Find 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, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $275 (Southwest) |
Popular in | August |
Cheapest in | June |
Average price | $401 |
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 7,457,451 searches. Data last updated September 16, 2026.
Use the filters below to find and compare flights from Islip to Knoxville that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
IslipKnoxville
ISP Islip Long Island - TYS Knoxville McGhee Tyson
ISPTYS
Islip Long Island
Sat 12/19
12:50 pm-9:35 pm
1 stop8h 45m
Knoxville McGhee Tyson
Mon 12/21
8:00 am-4:20 pm
1 stop8h 20m
$460
Quickest round-trip
IslipKnoxville
ISP Islip Long Island - TYS Knoxville McGhee Tyson
ISPTYS
Islip Long Island
Sat 9/26
2:00 pm-8:40 pm
1 stop6h 40m
Knoxville McGhee Tyson
Wed 9/30
8:05 am-12:10 pm
1 stop4h 05m
$467
IslipKnoxville
ISP Islip Long Island - TYS Knoxville McGhee Tyson
ISPTYS
Islip Long Island
Fri 11/6
12:25 pm-9:45 pm
1 stop9h 20m
Knoxville McGhee Tyson
Mon 11/9
12:50 pm-11:35 pm
2 stops10h 45m
$488
IslipKnoxville
ISP Islip Long Island - TYS Knoxville McGhee Tyson
ISPTYS
Islip Long Island
Sat 10/10
12:20 pm-7:40 pm
1 stop7h 20m
Knoxville McGhee Tyson
Sat 10/17
8:10 am-11:55 am
1 stop3h 45m
$508
IslipKnoxville
ISP Islip Long Island - TYS Knoxville McGhee Tyson
ISPTYS
Islip Long Island
Thu 10/22
6:25 pm-12:14 pm
1 stop17h 49m
Knoxville McGhee Tyson
Sun 10/25
7:00 am-5:30 pm
1 stop10h 30m
$510
IslipKnoxville
ISP Islip Long Island - TYS Knoxville McGhee Tyson
ISPTYS
Islip Long Island
Fri 10/2
3:10 pm-9:30 pm
1 stop6h 20m
Knoxville McGhee Tyson
Mon 10/5
12:50 pm-11:15 pm
1 stop10h 25m
$588
IslipKnoxville
ISP Islip Long Island - TYS Knoxville McGhee Tyson
ISPTYS
Islip Long Island
Wed 11/25
4:55 pm-9:45 pm
1 stop4h 50m
Knoxville McGhee Tyson
Sat 11/28
8:55 am-4:25 pm
1 stop7h 30m
$667
IslipKnoxville
ISP Islip Long Island - TYS Knoxville McGhee Tyson
ISPTYS
Islip Long Island
Fri 10/9
3:10 pm-9:35 pm
1 stop6h 25m
Knoxville McGhee Tyson
Fri 10/16
8:20 am-2:30 pm
1 stop6h 10m
$684
Sorted by cheapest first
Compare providers for flights from Islip to Knoxville
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 Islip to Knoxville in September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on Islip, New York-Knoxville flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Islip, New York-Knoxville flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Islip, New York-Knoxville flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Islip, New York-Knoxville flights, Cheapflights users trust FlightHub the most. FlightHub 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 Islip, New York-Knoxville 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 Islip to Knoxville
Have a flexible travel schedule? Discover the best time to fly to Knoxville from Islip with our price prediction graph.
ISP-TYS
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.
Reviews of airlines servicing Knoxville
Get insights into the airlines that provide service to Knoxville. 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 Knoxville. Reviews last updated September 16, 2026.
Peruse reviews from past customers who have flown with Southwest from Islip to Knoxville to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Crew
8.6
Entertainment
7.5
Overall
8.0
Food
7.0
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Crew
8.6
Entertainment
7.5
Overall
8.0
Food
7.0
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
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.
Traveling to a place near Knoxville?
Book flights to Knoxville if you plan to visit one of these locationsCherokee
Crossville
Morristown
Bryson City
Murphy
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Explore flights to Knoxville departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 16, 2026.
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Top airline flying from Islip to Knoxville
Discover the top airline that operate flights from Islip to Knoxville. 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 7,457,451 searches. Data last updated September 16, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$256 | Average$400 | FlexibilityNo cancel fee | On-time63% |