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Delaware

$125+ Cheap flights from Seattle (SEA) to Delaware

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/16. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ILG
Feb 18 — Feb 251
Wed 2/18
Wed 2/25
1 adult, Economy
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Cheap flight deals from Seattle to Delaware

Keep the following information in mind while searching for Seattle to Delaware flight deals. Data was last updated January 19, 2026.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$257
(Delta)

One-way from

$125
(Frontier)

Popular in

December

Cheapest in

October

Average price

$366
Provider with most accurate pricing for Seattle/Tacoma Intl-Philadelphia flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Philadelphia flights.
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From Seattle/Tacoma Intl to Delaware
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One-way flight from Seattle/Tacoma Intl to Delaware
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Highest demand for flights based on searches. 2% potential increase in price ($12 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($12 potential savings vs. average RT price).
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Average for round-trip flights in January 2026
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Find flight deals from Seattle to Delaware

Cheapest flights from Seattle to Delaware
Explore the most affordable flight options available from Seattle to Delaware. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 19, 2026.

This Delta deal was found by Cheapflights users on 1/18. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/2111:45 am
SEA
-
PHL
1 stop10h 06m
Delta
Fri 5/16:45 pm
PHL
-
SEA
1 stop8h 14m
Delta
Deal found 1/18$257
This Kiwi.com deal was found by Cheapflights users on 1/17. 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 2/211:16 pm
SEA
-
PHL
2 stops15h 16m
Frontier
Fri 2/277:05 pm
PHL
-
SEA
1 stop19h 56m
Frontier
Deal found 1/17$258
This Kiwi.com deal was found by Cheapflights users on 1/17. 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 2/191:16 pm
SEA
-
PHL
1 stop25h 39m
Frontier
Wed 2/2511:40 am
PHL
-
SEA
2 stops35h 28m
Frontier
Deal found 1/17$259
This United Airlines deal was found by Cheapflights users on 1/18. 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 Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/108:40 am
SEA
-
PHL
2 stops9h 56m
United Airlines
Sun 2/1512:55 pm
PHL
-
SEA
1 stop9h 08m
United Airlines
Deal found 1/18$262
This Expedia deal was found by Cheapflights users on 1/17. 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.
Mon 3/1612:24 pm
SEA
-
PHL
1 stop14h 07m
Multiple Airlines
Tue 3/316:47 pm
PHL
-
SEA
Nonstop6h 05m
Multiple Airlines
Deal found 1/17$263
This Kiwi.com deal was found by Cheapflights users on 1/17. 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 2/2312:30 pm
SEA
-
PHL
2 stops18h 57m
Frontier
Fri 2/277:05 pm
PHL
-
SEA
1 stop19h 56m
Frontier
Deal found 1/17$266
This Delta deal was found by Cheapflights users on 1/17. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/125:45 pm
SEA
-
PHL
1 stop8h 58m
Delta
Thu 5/147:05 am
PHL
-
SEA
Nonstop5h 59m
Delta
Deal found 1/17$267
This Kiwi.com deal was found by Cheapflights users on 1/17. 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 2/191:16 pm
SEA
-
PHL
1 stop25h 39m
Frontier
Mon 2/237:18 pm
PHL
-
SEA
2 stops24h 57m
Frontier
Deal found 1/17$270
This Kiwi.com deal was found by Cheapflights users on 1/17. 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.
Sun 2/2210:03 am
SEA
-
PHL
2 stops27h 34m
Frontier
Fri 2/277:05 pm
PHL
-
SEA
1 stop19h 56m
Frontier
Deal found 1/17$276
This American Airlines deal was found by Cheapflights users on 1/18. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/2010:57 pm
SEA
-
PHL
Nonstop5h 05m
American Airlines
Sun 3/16:35 pm
PHL
-
SEA
Nonstop6h 22m
American Airlines
Deal found 1/18$277
This Kiwi.com deal was found by Cheapflights users on 1/17. 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 2/2012:00 pm
SEA
-
PHL
2 stops19h 42m
Frontier
Thu 2/265:47 pm
PHL
-
SEA
1 stop20h 08m
Frontier
Deal found 1/17$284
This United Airlines deal was found by Cheapflights users on 1/18. 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 Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/1211:59 pm
SEA
-
PHL
1 stop7h 15m
United Airlines
Sat 3/146:20 pm
PHL
-
SEA
1 stop9h 39m
United Airlines
Deal found 1/18$286

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to Delaware 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 2,558,603 searches. Data last updated January 19, 2026.
Use the filters below to find and compare flights from Seattle to Delaware that are best for you.

Fly from

Seattle

Fly to

Delaware

Route

Depart

Return

Price

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 4/16

9:55 pm-6:05 am

Nonstop5h 10m

Philadelphia

Mon 4/20

6:47 pm-9:52 pm

Nonstop6h 05m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 5/28

9:50 pm-6:05 am

Nonstop5h 15m

Philadelphia

Sat 6/6

7:05 am-10:04 am

Nonstop5h 59m

$277

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Sat 2/21

6:50 am-9:10 pm

2 stops11h 20m

Philadelphia

Tue 2/24

1:50 pm-10:30 pm

2 stops11h 40m

$295

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 2/25

6:00 am-5:09 pm

1 stop8h 09m

Philadelphia

Mon 3/2

6:35 pm-9:57 pm

Nonstop6h 22m

$297

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 2/25

10:57 pm-7:02 am

Nonstop5h 05m

Philadelphia

Sun 3/1

4:33 pm-12:24 am

1 stop10h 51m

$297

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Mon 2/23

6:00 am-4:32 pm

1 stop7h 32m

Philadelphia

Fri 2/27

5:25 pm-10:05 pm

1 stop7h 40m

$297

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 3/18

10:08 pm-9:55 am

1 stop8h 47m

Philadelphia

Mon 3/23

6:35 pm-9:57 pm

Nonstop6h 22m

$297

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Sat 3/28

11:55 pm-10:45 am

1 stop7h 50m

Philadelphia

Fri 4/3

5:10 pm-10:50 pm

1 stop8h 40m

$306

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Thu 2/19

9:16 am-5:20 pm

Nonstop5h 04m

Philadelphia

Wed 2/25

6:20 pm-9:33 pm

Nonstop6h 13m

$307

SeattlePhiladelphia

SEA - PHL

SEAPHL

Seattle/Tacoma Intl

Wed 5/20

9:50 pm-6:05 am

Nonstop5h 15m

Philadelphia

Mon 6/1

7:05 am-10:04 am

Nonstop5h 59m

$307

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/18

Showing 1-10 of 26 results
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Best time to book a flight from Seattle to Delaware

Have a flexible travel schedule? Discover the best time to fly to Delaware from Seattle with our price prediction graph.
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.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Delaware
No data available for this route at this time. Please check back soon.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Delaware. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Seattle to Delaware?

    Most people fly from Seattle/Tacoma Intl (SEA) if they book a flight from Seattle to Delaware. Seattle/Tacoma Intl is conveniently located just 11.4 mi from Seattle’s city center.

  • How long is the flight from Seattle to Delaware?

    Airlines like Alaska Airlines, Delta, and Southwest fly from Seattle to Delaware in about 5h 10m. The time it takes to get you to your destination can typically vary by up to 6h 10m. Seattle and Delaware are separated by a distance of 2370 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • Can I find deals for flights from Seattle to Delaware that include hotel bookings?

    Yes. In addition to deals on Seattle to Delaware flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Delaware?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Delaware.

  • Can I find deals for business class flights from Seattle to Delaware?

    Yes. Cheapflights offers flight deals from Seattle to Delaware by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

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