What airlines fly to Seattle?

Alaska Airlines, United Airlines and Delta are the top three most popular airlines that fly to Seattle from Islip, New York according to our data. Alaska Airlines is the first choice among our users, with 45% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 10 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

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?

As of January 2026, there is 1 operator available to choose from 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.

$442 Cheap Flights from Islip to Seattle in 2026

1 adult

0 bags

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Find the cheapest flights from Islip, New York to Seattle

Round-trip

One-way

Cheap round-trip flights

Enter your travel dates to find the best prices.

5:55 am - 6:30 pm

ISP

SEA

15h 35m

2 stops

6:25 pm - 11:55 am

SEA

ISP

14h 30m

2 stops

$442Southwest

Thu, Feb 19 - Sun, Feb 22

12:30 pm - 10:17 pm

ISP

SEA

12h 47m

1 stop

7:55 am - 7:45 pm

SEA

ISP

8h 50m

1 stop

$1,064Multiple Airlines

Tue, Jan 27 - Sat, Jan 31

9:59 am - 10:00 pm

ISP

SEA

15h 01m

1 stop

10:48 pm - 6:44 pm

SEA

ISP

16h 56m

2 stops

$1,178Multiple Airlines

Thu, Feb 19 - Sun, Feb 22

Fly from

Fly to

Route

Depart

Return

Price

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Thu 2/19

5:55 am-6:30 pm

2 stops15h 35m

Seattle/Tacoma Intl

Sun 2/22

6:25 pm-11:55 am

2 stops14h 30m

$442

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Tue 1/27

12:30 pm-10:17 pm

1 stop12h 47m

Seattle/Tacoma Intl

Sat 1/31

7:55 am-7:45 pm

1 stop8h 50m

$1,064

IslipSeattle

ISP - SEA

ISPSEA

Islip Long Island

Thu 2/19

9:59 am-10:00 pm

1 stop15h 01m

Seattle/Tacoma Intl

Sun 2/22

10:48 pm-6:44 pm

2 stops16h 56m

$1,178

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

How to get the cheapest flight ticket from Islip, New York 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

Prices

Airlines

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

On average, the least expensive day to fly to Seattle from Islip, New York is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $457. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Monday is the most expensive day to depart from Islip, New York because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $540.

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

Flying to Seattle from Islip, New York in the evening is the least expensive time of day to depart. momondo users have found prices as low as $377 when looking at flights departing in the evening. Flights to Seattle are more costly at noon, with an average ticket price of $577. 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, New York to Seattle flights?

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

When to book flights from Islip, New York to Seattle

Are you open to changing your travel dates? Check out the ideal times to fly from Islip, New York to Seattle according to our flight data. Find out which month and days have the cheapest flights.

Estimated round-trip price

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

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

Fastest flight time	26h 42m
Direct flights	None

The fastest flight from Islip, New York to Seattle takes 26h 42m

There are no direct flights from Islip, New York to Seattle. There are no popular flight routes from Islip, New York to Seattle.

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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 26h 42m.
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?
As of January 2026, there is 1 operator available to choose from 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, New York to Seattle?
momondo data reveals that the most frequently booked airline on the route from Islip, New York to Seattle is Southwest, representing 100% of all bookings.

Best airlines flying from Islip, New York to Seattle

Compare and see reviews for airlines that fly from Islip, New York to Seattle with momondo

Airline	Rating	Free Cancellation	Price
Southwest	PriceFrom $356	Free Cancellation	Rating 8.0 4,253 reviews		Search Southwest flights

Tacoma

Leavenworth

SeaTac

Ocean Shores

Renton

Olympia

Lynnwood

Kent

Marysville

Puyallup

Redmond

Tukwila

Federal Way

Cle Elum

Lakewood

Fife

Westport

Kirkland

Centralia

Shoreline

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.