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Cheap flights from Islip to Seattle from $169

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 10/7. 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 (ISP-SEA)

Cheap round-trip flights

Southwest Logo
3:40 pm - 8:30 pmISP-SEA
7h 50m1 stop
Southwest Logo
11:10 pm - 3:10 pmSEA-ISP
13h 00m2 stops
$372Southwest
Find Deal
Sat, Sep 27 - Mon, Sep 29
Southwest Logo
3:40 pm - 8:30 pmISP-SEA
7h 50m1 stop
Southwest Logo
9:10 pm - 11:55 amSEA-ISP
11h 45m1 stop
$392Southwest
Find Deal
Sat, Sep 27 - Mon, Sep 29
Southwest Logo
12:55 pm - 9:50 pmISP-SEA
11h 55m2 stops
Southwest Logo
11:10 pm - 11:55 amSEA-ISP
9h 45m2 stops
$397Southwest
Find Deal
Sat, Sep 27 - Mon, Sep 29
Southwest Logo
6:05 am - 11:15 amISP-SEA
8h 10m1 stop
Southwest Logo
11:10 pm - 2:55 pmSEA-ISP
12h 45m2 stops
$698Southwest
Find Deal
Tue, Sep 9 - Fri, Sep 19
Southwest Logo
4:00 pm - 11:10 pmISP-SEA
10h 10m2 stops
Southwest Logo
11:10 pm - 2:55 pmSEA-ISP
12h 45m2 stops
$703Southwest
Find Deal
Tue, Sep 9 - Fri, Sep 19
Southwest Logo
6:05 am - 11:15 amISP-SEA
8h 10m1 stop
Southwest Logo
9:10 pm - 12:05 pmSEA-ISP
11h 55m1 stop
$706Southwest
Find Deal
Tue, Sep 9 - Fri, Sep 19
Frontier Logo
9:47 pm - 3:16 pmISP-SEA
20h 29m2 stops
Frontier Logo
2:31 pm - 10:37 amSEA-ISP
17h 06m2 stops
$757Frontier
Find Deal
Sun, Oct 12 - Sun, Oct 19
Logo
4:33 pm - 10:08 pmISP-SEA
8h 35m1 stop
Logo
11:16 pm - 10:55 amSEA-ISP
32h 39m2 stops
$834
Find Deal
Fri, Sep 12 - Tue, Sep 16
Logo
4:33 pm - 10:08 pmISP-SEA
8h 35m1 stop
Logo
11:15 pm - 10:58 amSEA-ISP
8h 43m1 stop
$878
Find Deal
Thu, Oct 2 - Sun, Oct 5
Logo
4:33 pm - 10:08 pmISP-SEA
8h 35m1 stop
Logo
11:15 pm - 10:58 amSEA-ISP
8h 43m1 stop
$897
Find Deal
Fri, Oct 3 - Mon, Oct 6

Southwest flights from Islip to Seattle

Our best Southwest deals on Islip to Seattle flight tickets
Southwest
Sep 27
ISP3:40 pmIslip Long Island
7h 50m
1 stop
SEA8:30 pmSeattle/Tacoma Intl
Sep 29
SEA11:10 pmSeattle/Tacoma Intl
13h 00m
2 stops
ISP3:10 pmIslip Long Island
$372
Find similar
Southwest
Sep 27
ISP3:40 pmIslip Long Island
7h 50m
1 stop
SEA8:30 pmSeattle/Tacoma Intl
Sep 29
SEA9:10 pmSeattle/Tacoma Intl
11h 45m
1 stop
ISP11:55 amIslip Long Island
$392
Find similar
Southwest
Sep 27
ISP12:55 pmIslip Long Island
11h 55m
2 stops
SEA9:50 pmSeattle/Tacoma Intl
Sep 29
SEA11:10 pmSeattle/Tacoma Intl
9h 45m
2 stops
ISP11:55 amIslip Long Island
$397
Find similar

Frontier flights from Islip to Seattle

Our best Frontier deals on Islip to Seattle flight tickets
Frontier
Oct 12
ISP9:47 pmIslip Long Island
20h 29m
2 stops
SEA3:16 pmSeattle/Tacoma Intl
Oct 19
SEA2:31 pmSeattle/Tacoma Intl
17h 06m
2 stops
ISP10:37 amIslip Long Island
$757
Find similar
Frontier
Sep 1
ISP7:27 pmIslip Long Island
30h 34m
2 stops
SEA11:01 pmSeattle/Tacoma Intl
Sep 3
SEA6:41 amSeattle/Tacoma Intl
30h 46m
2 stops
ISP4:27 pmIslip Long Island
$773
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 August 28, 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 9/27

3:40 pm-8:30 pm

1 stop7h 50m

Seattle/Tacoma Intl

Mon 9/29

11:10 pm-3:10 pm

2 stops13h 00m

$372

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Sat 9/27

3:40 pm-8:30 pm

1 stop7h 50m

Seattle/Tacoma Intl

Mon 9/29

9:10 pm-11:55 am

1 stop11h 45m

$392

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Sat 9/27

12:55 pm-9:50 pm

2 stops11h 55m

Seattle/Tacoma Intl

Mon 9/29

11:10 pm-11:55 am

2 stops9h 45m

$397

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Tue 9/9

6:05 am-11:15 am

1 stop8h 10m

Seattle/Tacoma Intl

Fri 9/19

11:10 pm-2:55 pm

2 stops12h 45m

$698

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Tue 9/9

4:00 pm-11:10 pm

2 stops10h 10m

Seattle/Tacoma Intl

Fri 9/19

11:10 pm-2:55 pm

2 stops12h 45m

$703

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Tue 9/9

6:05 am-11:15 am

1 stop8h 10m

Seattle/Tacoma Intl

Fri 9/19

9:10 pm-12:05 pm

1 stop11h 55m

$706

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Sun 10/12

9:47 pm-3:16 pm

2 stops20h 29m

Seattle/Tacoma Intl

Sun 10/19

2:31 pm-10:37 am

2 stops17h 06m

$757

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Fri 9/12

4:33 pm-10:08 pm

1 stop8h 35m

Seattle/Tacoma Intl

Tue 9/16

11:16 pm-10:55 am

2 stops32h 39m

$834

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Thu 10/2

4:33 pm-10:08 pm

1 stop8h 35m

Seattle/Tacoma Intl

Sun 10/5

11:15 pm-10:58 am

1 stop8h 43m

$878

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Fri 10/3

4:33 pm-10:08 pm

1 stop8h 35m

Seattle/Tacoma Intl

Mon 10/6

11:15 pm-10:58 am

1 stop8h 43m

$897

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Seattle from

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 $470. 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 $571.

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 $568. Departure times at noon fall within the peak daily travel times, which is why tickets can be more expensive.

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 7h 50m.

  • 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
Olympia
Renton
Lynnwood
Kent
Marysville
Puyallup
Federal Way
Cle Elum
Tukwila
Kirkland
Centralia
Lakewood
Shoreline
Fife
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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