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Cheap flights from Islip to Seattle from $216

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Islip to Seattle departing on 10/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Islip to Seattle

Cheap round-trip flights

Frontier Logo
4:58 pm - 7:33 amISP-SEA
17h 35m2 stops
Frontier Logo
1:02 pm - 9:04 amSEA-ISP
17h 02m2 stops
$291Frontier
Find Deal
Sat, Oct 11 - Thu, Oct 16
Frontier Logo
9:37 pm - 12:07 pmISP-SEA
17h 30m2 stops
Frontier Logo
12:58 pm - 10:37 amSEA-ISP
18h 39m2 stops
$297Frontier
Find Deal
Thu, Oct 23 - Tue, Oct 28
Frontier Logo
4:58 pm - 7:33 amISP-SEA
17h 35m2 stops
Frontier Logo
2:31 pm - 9:44 amSEA-ISP
16h 13m2 stops
$327Frontier
Find Deal
Sat, Oct 11 - Mon, Oct 20
Frontier Logo
4:58 pm - 7:33 amISP-SEA
17h 35m2 stops
Frontier Logo
2:31 pm - 11:53 amSEA-ISP
18h 22m2 stops
$337Frontier
Find Deal
Sat, Oct 11 - Fri, Oct 17
Frontier Logo
9:37 pm - 12:07 pmISP-SEA
17h 30m2 stops
Frontier Logo
1:02 pm - 10:37 amSEA-ISP
18h 35m2 stops
$344Frontier
Find Deal
Thu, Oct 16 - Thu, Oct 23
Frontier Logo
9:49 am - 12:30 amISP-SEA
17h 41m2 stops
Frontier Logo
1:02 pm - 2:13 pmSEA-ISP
22h 11m2 stops
$345Frontier
Find Deal
Sun, Oct 5 - Tue, Oct 7
Southwest Logo
6:00 am - 5:50 pmISP-SEA
14h 50m2 stops
Southwest Logo
9:00 am - 10:50 pmSEA-ISP
10h 50m2 stops
$413Southwest
Find Deal
Tue, Mar 3 - Tue, Mar 31
Southwest Logo
3:25 pm - 12:35 amISP-SEA
12h 10m2 stops
Southwest Logo
7:50 am - 10:50 pmSEA-ISP
12h 00m2 stops
$627Southwest
Find Deal
Mon, Nov 24 - Sat, Nov 29
Multiple Airlines Logo
4:33 pm - 10:08 pmISP-SEA
8h 35m1 stop
Multiple Airlines Logo
11:15 pm - 10:58 amSEA-ISP
8h 43m1 stop
$840Multiple Airlines
Find Deal
Sat, Sep 27 - Sat, Oct 4
Multiple Airlines Logo
12:40 pm - 9:18 pmISP-SEA
11h 38m1 stop
Multiple Airlines Logo
10:50 pm - 11:04 amSEA-ISP
9h 14m1 stop
$894Multiple Airlines
Find Deal
Tue, Mar 3 - Tue, Mar 31

Southwest flights from Islip to Seattle

Our best Southwest deals on Islip to Seattle flight tickets
Southwest
Mar 3
ISP6:00 amIslip Long Island
14h 50m
2 stops
SEA5:50 pmSeattle/Tacoma Intl
Mar 31
SEA9:00 amSeattle/Tacoma Intl
10h 50m
2 stops
ISP10:50 pmIslip Long Island
$413
Find similar
Southwest
Nov 24
ISP3:25 pmIslip Long Island
12h 10m
2 stops
SEA12:35 amSeattle/Tacoma Intl
Nov 29
SEA7:50 amSeattle/Tacoma Intl
12h 00m
2 stops
ISP10:50 pmIslip Long Island
$627
Find similar

Frontier flights from Islip to Seattle

Our best Frontier deals on Islip to Seattle flight tickets
Frontier
Oct 11
ISP4:58 pmIslip Long Island
17h 35m
2 stops
SEA7:33 amSeattle/Tacoma Intl
Oct 16
SEA1:02 pmSeattle/Tacoma Intl
17h 02m
2 stops
ISP9:04 amIslip Long Island
$291
Find similar
Frontier
Oct 23
ISP9:37 pmIslip Long Island
17h 30m
2 stops
SEA12:07 pmSeattle/Tacoma Intl
Oct 28
SEA12:58 pmSeattle/Tacoma Intl
18h 39m
2 stops
ISP10:37 amIslip Long Island
$297
Find similar
Frontier
Oct 11
ISP4:58 pmIslip Long Island
17h 35m
2 stops
SEA7:33 amSeattle/Tacoma Intl
Oct 20
SEA2:31 pmSeattle/Tacoma Intl
16h 13m
2 stops
ISP9:44 amIslip Long Island
$327
Find similar

momondo 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, momondo users made 832,500 searches. Data last updated September 17, 2025.
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

Price

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Sat 10/11

4:58 pm-7:33 am

2 stops17h 35m

Seattle/Tacoma Intl

Thu 10/16

1:02 pm-9:04 am

2 stops17h 02m

$291

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Thu 10/23

9:37 pm-12:07 pm

2 stops17h 30m

Seattle/Tacoma Intl

Tue 10/28

12:58 pm-10:37 am

2 stops18h 39m

$297

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Sat 10/11

4:58 pm-7:33 am

2 stops17h 35m

Seattle/Tacoma Intl

Mon 10/20

2:31 pm-9:44 am

2 stops16h 13m

$327

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Sat 10/11

4:58 pm-7:33 am

2 stops17h 35m

Seattle/Tacoma Intl

Fri 10/17

2:31 pm-11:53 am

2 stops18h 22m

$337

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Thu 10/16

9:37 pm-12:07 pm

2 stops17h 30m

Seattle/Tacoma Intl

Thu 10/23

1:02 pm-10:37 am

2 stops18h 35m

$344

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Sun 10/5

9:49 am-12:30 am

2 stops17h 41m

Seattle/Tacoma Intl

Tue 10/7

1:02 pm-2:13 pm

2 stops22h 11m

$345

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Tue 3/3

6:00 am-5:50 pm

2 stops14h 50m

Seattle/Tacoma Intl

Tue 3/31

9:00 am-10:50 pm

2 stops10h 50m

$413

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Mon 11/24

3:25 pm-12:35 am

2 stops12h 10m

Seattle/Tacoma Intl

Sat 11/29

7:50 am-10:50 pm

2 stops12h 00m

$627

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Sat 9/27

4:33 pm-10:08 pm

1 stop8h 35m

Seattle/Tacoma Intl

Sat 10/4

11:15 pm-10:58 am

1 stop8h 43m

$840

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Tue 3/3

12:40 pm-9:18 pm

1 stop11h 38m

Seattle/Tacoma Intl

Tue 3/31

10:50 pm-11:04 am

1 stop9h 14m

$894

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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How to get the cheapest flight ticket from Islip to Seattle

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to Seattle?

On average, the least expensive day to fly to Seattle from Islip is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $469. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Sunday is the most expensive day to depart from Islip because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $569.

What is the cheapest time of day to depart on your flight to Seattle?

Flying to Seattle from Islip in the evening is the least expensive time of day to depart. momondo users have found prices as low as $402 when looking at flights departing in the evening. Flights to Seattle are more costly at noon, with an average ticket price of $566. Departure times at noon fall within the peak daily travel times, which is why tickets can be more expensive.

Can stopping save me money on Islip to Seattle flights?

You could potentially save up to 6% on your flight if you consider stops on a Islip to Seattle flight.

When to book flights from Islip to Seattle

Are you open to changing your travel dates? Check out the ideal times to fly from Islip to Seattle according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Islip to Seattle (ISP to SEA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Islip to Seattle

Direct flights

None
There are no direct flights from Islip to Seattle. There are no popular flight routes from Islip to Seattle.
Search flight deals

  • How far is Islip Long Island to Seattle/Tacoma Intl by plane?

    Seattle/Tacoma Intl is 2436.8 mi away from Islip Long Island. By plane, this route typically takes 8h 35m.

  • When did momondo last update prices for flights from Islip Long Island Airport to Seattle/Tacoma Intl Airport?

    Prices for flights from Islip Long Island Airport to Seattle/Tacoma Intl Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Islip Long Island Airport to Seattle/Tacoma Intl Airport?

  • How old do you have to be to fly from Islip Long Island Airport to Seattle/Tacoma Intl Airport?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Islip Long Island Airport to Seattle/Tacoma Intl Airport.

  • What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

    The required travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Seattle/Tacoma Intl Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

  • What is the most popular airline from Islip to Seattle?

Best airlines flying from Islip to Seattle

Compare and see reviews for airlines that fly from Islip to Seattle with momondo
Airline
Rating
Free Cancellation
Price
SouthwestPriceFrom $356Free CancellationRating
8.0
4,242 reviews
Search Southwest flights

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Leavenworth
Tacoma
SeaTac
Ocean Shores
Renton
Olympia
Lynnwood
Kent
Marysville
Puyallup
Federal Way
Kirkland
Tukwila
Shoreline
Lakewood
Centralia
Fife
Cle Elum
Redmond
Westport

Why use momondo?

Why should I use momondo to find a flight deal from Islip to Seattle?

Finding the right flight to Seattle from Islip is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Seattle quick and easy, saving you time and money.

Can I find flights from Islip to Seattle with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to Seattle from Islip with this policy.

How can momondo help me find flights from Islip to Seattle?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Seattle from Islip.

I’m not ready to book a flight from Islip to Seattle right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Seattle, momondo offers a useful price alert feature which will track prices for flights to Seattle from Islip and alert you when they change.

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