$237+ Cheap flights from Islip, NY to Seattle (ISP - SEA)
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 10/12. Fares are subject to change and may not be available on all flights or dates of travel.
ISP — SEA
Oct 12 — Oct 191
Round-trip
1 adult, Economy
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Find cheap flights from Islip to Seattle 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 Seattle
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Best
Last-minute
One-way
Cheapest flights from Islip to SeattleExplore the most affordable flight options available from Islip to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 12, 2026.
Explore the most affordable flight options available from Islip to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 12, 2026.
This Southwest deal was found by Cheapflights users on 9/7. 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 10/69:40 am -
2 stops11h 25m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/7![Southwest logo]()
$469
This Southwest deal was found by Cheapflights users on 9/7. 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 -
2 stops12h 50m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/7![Southwest logo]()
$501
This Southwest deal was found by Cheapflights users on 9/10. 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 10/712:50 pm -
2 stops13h 10m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/10![Southwest logo]()
$525
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.
Mon 10/53:10 pm -
2 stops12h 50m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/11![Southwest logo]()
$562
This Southwest deal was found by Cheapflights users on 9/10. 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 9/2510:20 am -
1 stop7h 40m
Tue 9/2910:30 pm -
1 stop8h 45m
Deal found 9/10![Southwest logo]()
$597
This Southwest deal was found by Cheapflights users on 9/8. 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.
Thu 9/2410:20 am -
2 stops10h 15m
Mon 9/2810:30 pm -
1 stop8h 45m
Deal found 9/8![Southwest logo]()
$602
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.
Thu 10/83:10 pm -
2 stops12h 50m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/11![Southwest logo]()
$630
This Expedia deal was found by Cheapflights users on 9/7. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/96:55 pm -
2 stops23h 17m
Sun 10/1111:55 pm -
1 stop8h 01m
Deal found 9/7![Multiple Airlines logo]()
$900
Best flights from Islip to SeattleDiscover carefully curated flight deals from Islip to Seattle that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 12, 2026.
Discover carefully curated flight deals from Islip to Seattle that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 12, 2026.
This Southwest deal was found by Cheapflights users on 9/7. 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 10/69:40 am -
2 stops11h 25m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/7![Southwest logo]()
$469
This Expedia deal was found by Cheapflights users on 9/7. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/96:55 pm -
2 stops23h 17m
Sun 10/1111:55 pm -
1 stop8h 01m
Deal found 9/7![Multiple Airlines logo]()
$900
This Southwest deal was found by Cheapflights users on 9/7. 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 -
2 stops12h 50m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/7![Southwest logo]()
$501
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.
Wed 10/712:50 pm -
2 stops13h 10m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/11![Southwest logo]()
$562
This Southwest deal was found by Cheapflights users on 9/10. 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 9/2510:20 am -
1 stop7h 40m
Tue 9/2910:30 pm -
1 stop8h 45m
Deal found 9/10![Southwest logo]()
$597
This Southwest deal was found by Cheapflights users on 9/8. 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.
Thu 9/2410:20 am -
2 stops10h 15m
Mon 9/2810:30 pm -
1 stop8h 45m
Deal found 9/8![Southwest logo]()
$602
Last-minute flights from Islip to SeattleDiscover last-minute flight deals from Islip to Seattle. Data last updated September 12, 2026 and is based on user searches.
Discover last-minute flight deals from Islip to Seattle. Data last updated September 12, 2026 and is based on user searches.
This Southwest deal was found by Cheapflights users on 9/8. 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.
Thu 9/2410:20 am -
2 stops10h 15m
Mon 9/2810:30 pm -
1 stop8h 45m
Deal found 9/8![Southwest logo]()
$602
This Southwest deal was found by Cheapflights users on 9/10. 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 9/2510:20 am -
1 stop7h 40m
Tue 9/2910:30 pm -
1 stop8h 45m
Deal found 9/10![Southwest logo]()
$597
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.
Mon 10/53:10 pm -
2 stops12h 50m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/11![Southwest logo]()
$562
This Southwest deal was found by Cheapflights users on 9/7. 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 10/69:40 am -
2 stops11h 25m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/7![Southwest logo]()
$469
This Southwest deal was found by Cheapflights users on 9/10. 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 10/712:50 pm -
2 stops13h 10m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/10![Southwest logo]()
$525
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.
Thu 10/83:10 pm -
2 stops12h 50m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/11![Southwest logo]()
$630
This Southwest deal was found by Cheapflights users on 9/7. 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 -
2 stops12h 50m
Sun 10/119:15 pm -
2 stops14h 15m
Deal found 9/7![Southwest logo]()
$501
This Expedia deal was found by Cheapflights users on 9/7. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/96:55 pm -
2 stops23h 17m
Sun 10/1111:55 pm -
1 stop8h 01m
Deal found 9/7![Multiple Airlines logo]()
$900
One-way flights from Islip to SeattleSearch for one-way flight options from Islip to Seattle. Find affordable one-way fares based on user searches. Data last updated September 12, 2026.
Search for one-way flight options from Islip to Seattle. Find affordable one-way fares based on user searches. Data last updated September 12, 2026.
This Kiwi.com deal was found by Cheapflights users on 9/10. 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.
Mon 10/126:55 pm -
2 stops23h 17m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$237
This Kiwi.com deal was found by Cheapflights users on 9/10. 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.
Mon 10/123:02 pm -
3 stops27h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Multiple Airlines logo]()
$294
This Southwest deal was found by Cheapflights users on 9/8. 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 9/195:30 am -
1 stop8h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Southwest logo]()
$494
This Southwest deal was found by Cheapflights users on 9/8. 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.
Sun 9/206:20 am -
1 stop11h 20m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Southwest logo]()
$499
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/96:55 pm -
2 stops23h 17m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/11![Frontier logo]()
$552
This United deal was found by Cheapflights users on 9/8. 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 United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/217:31 am -
3 stops41h 00m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Multiple Airlines logo]()
$558
This United deal was found by Cheapflights users on 9/8. 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 United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/207:05 am -
3 stops41h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Multiple Airlines logo]()
$1,059
Find flight deals from Islip to Seattle
Discover tips and strategies to find the most affordable flight options for your journey from Islip (ISP) to Seattle (SEA). 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 12, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $469 (Southwest) |
One-way from | $237 (Kiwi.com) |
Popular in | August |
Cheapest in | October |
Average price | $398 |
Cheapflights Fare Finder
Customize your flight search to find flights from Islip to Seattle 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 12, 2026.
Use the filters below to find and compare flights from Islip to Seattle that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Mon 10/12
6:55 pm-3:12 pm
2 stops23h 17m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$237
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Mon 10/12
3:02 pm-3:12 pm
3 stops27h 10m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$294
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Tue 10/6
9:40 am-6:05 pm
2 stops11h 25m
Seattle/Tacoma Intl
Sun 10/11
9:15 pm-2:30 pm
2 stops14h 15m
$469
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Sat 9/19
11:55 am-11:00 pm
2 stops14h 05m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$499
Quickest round-trip
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Mon 9/21
6:10 am-1:15 pm
2 stops10h 05m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$499
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Sun 9/20
6:20 am-1:40 pm
2 stops10h 20m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$499
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Fri 10/9
3:10 pm-1:00 am
2 stops12h 50m
Seattle/Tacoma Intl
Sun 10/11
9:15 pm-2:30 pm
2 stops14h 15m
$501
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Fri 10/9
6:55 pm-3:12 pm
2 stops23h 17m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$552
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Mon 9/21
10:05 am-10:25 am
1 stop27h 20m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$558
IslipSeattle
ISP Islip Long Island - SEA Seattle/Tacoma Intl
ISPSEA
Islip Long Island
Wed 10/7
12:50 pm-11:00 pm
2 stops13h 10m
Seattle/Tacoma Intl
Sun 10/11
9:15 pm-2:30 pm
2 stops14h 15m
$562
Showing 1-10 of 14 resultsSorted by cheapest first
Compare providers for flights from Islip to Seattle
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 Seattle 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-Seattle 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-Seattle flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Islip, New York-Seattle flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Islip, New York-Seattle 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-Seattle 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 Seattle
Have a flexible travel schedule? Discover the best time to fly to Seattle from Islip with our price prediction graph.
ISP-SEA
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.
Related info for your journey
Find useful and relevant information for your journey from Islip to Seattle. 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 Seattle?
Book flights to Seattle if you plan to visit one of these locationsSeaTac
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