$165+ 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 7/15. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ILG
Jun 22 — Jun 291
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to Delaware 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
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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 Seattle to Delaware
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Cheapest flights from Seattle to DelawareExplore 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 May 23, 2026.
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 May 23, 2026.
This Delta deal was found by Cheapflights users on 5/18. 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.
Wed 7/19:25 am
SEA
- PHL
Nonstop5h 10m
Delta
Fri 7/36:45 pm
PHL
- SEA
Nonstop6h 14m
Delta
Deal found 5/18![Delta logo]()
$329
This American Airlines deal was found by Cheapflights users on 5/20. 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 7/312:39 pm
SEA
- PHL
Nonstop5h 26m
American Airlines
Sat 7/117:35 pm
PHL
- SEA
Nonstop6h 21m
American Airlines
Deal found 5/20![American Airlines logo]()
$330
This Delta deal was found by Cheapflights users on 5/18. 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 6/99:25 am
SEA
- PHL
Nonstop5h 10m
Delta
Sun 6/216:45 pm
PHL
- SEA
Nonstop6h 14m
Delta
Deal found 5/18![Delta logo]()
$333
This Delta deal was found by Cheapflights users on 5/18. 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.
Fri 5/299:20 pm
SEA
- PHL
Nonstop5h 17m
Delta
Tue 6/96:45 pm
PHL
- SEA
Nonstop6h 14m
Delta
Deal found 5/18![Delta logo]()
$337
This Delta deal was found by Cheapflights users on 5/18. 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.
Wed 7/19:25 am
SEA
- PHL
Nonstop5h 10m
Delta
Sat 7/47:23 am
PHL
- SEA
1 stop8h 29m
Delta
Deal found 5/18![Delta logo]()
$338
This Delta deal was found by Cheapflights users on 5/20. 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 8/119:53 am
SEA
- PHL
1 stop6h 32m
Delta
Wed 8/197:00 am
PHL
- SEA
Nonstop5h 56m
Delta
Deal found 5/20![Delta logo]()
$339
This CheapOair deal was found by Cheapflights users on 5/18. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/87:50 pm
SEA
- PHL
1 stop12h 57m
Frontier
Wed 6/1011:00 am
PHL
- SEA
1 stop26h 35m
Frontier
Deal found 5/18![Frontier logo]()
$340
This Super.com deal was found by Cheapflights users on 5/18. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/103:33 pm
SEA
- PHL
1 stop17h 14m
Frontier
Fri 6/1211:00 am
PHL
- SEA
1 stop26h 35m
Frontier
Deal found 5/18![Frontier logo]()
$342
This Delta deal was found by Cheapflights users on 5/18. 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.
Fri 5/2911:59 pm
SEA
- PHL
1 stop7h 33m
Delta
Mon 6/86:45 pm
PHL
- SEA
Nonstop6h 14m
Delta
Deal found 5/18![Delta logo]()
$347
This Travelocity deal was found by Cheapflights users on 5/18. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/13:19 pm
SEA
- PHL
1 stop11h 18m
Frontier
Tue 6/97:06 pm
PHL
- SEA
1 stop18h 29m
Frontier
Deal found 5/18![Frontier logo]()
$350
This American Airlines deal was found by Cheapflights users on 5/19. 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.
Wed 7/87:10 am
SEA
- SBY
1 stop10h 20m
American Airlines
Wed 7/154:33 pm
SBY
- SEA
1 stop9h 27m
American Airlines
Deal found 5/19![American Airlines logo]()
$704
This American Airlines deal was found by Cheapflights users on 5/18. 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 6/198:10 am
SEA
- SBY
1 stop12h 00m
American Airlines
Tue 6/306:40 am
SBY
- SEA
1 stop17h 55m
American Airlines
Deal found 5/18![American Airlines logo]()
$758
Best flights from Seattle to DelawareDiscover carefully curated flight deals from Seattle to Delaware that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated May 23, 2026.
Discover carefully curated flight deals from Seattle to Delaware that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated May 23, 2026.
This Delta deal was found by Cheapflights users on 5/18. 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 8/49:29 pm
SEA
- PHL
Nonstop5h 11m
Delta
Tue 8/117:00 am
PHL
- SEA
Nonstop5h 56m
Delta
Deal found 5/18![Delta logo]()
$329
This Southwest deal was found by Cheapflights users on 5/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/15:00 am
SEA
- PHL
1 stop7h 50m
Southwest
Mon 10/512:20 pm
PHL
- SEA
2 stops11h 05m
Southwest
Deal found 5/18![Southwest logo]()
$354
This United Airlines deal was found by Cheapflights users on 5/22. 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.
Wed 6/2412:50 pm
SEA
- PHL
1 stop7h 40m
United Airlines
Sun 6/286:30 pm
PHL
- SEA
1 stop9h 45m
United Airlines
Deal found 5/22![United Airlines logo]()
$359
This Delta deal was found by Cheapflights users on 5/20. 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.
Mon 8/249:29 pm
SEA
- PHL
Nonstop5h 11m
Delta
Thu 8/277:00 pm
PHL
- SEA
1 stop7h 59m
Delta
Deal found 5/20![Delta logo]()
$339
This Delta deal was found by Cheapflights users on 5/22. 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.
Fri 8/76:09 pm
SEA
- PHL
1 stop8h 56m
Delta
Sat 8/297:00 am
PHL
- SEA
Nonstop5h 56m
Delta
Deal found 5/22![Delta logo]()
$339
This American Airlines deal was found by Cheapflights users on 5/18. 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.
Tue 6/28:10 am
SEA
- SBY
1 stop12h 00m
American Airlines
Thu 1/286:30 am
SBY
- SEA
1 stop18h 37m
American Airlines
Deal found 5/18![American Airlines logo]()
$800
This Delta deal was found by Cheapflights users on 5/22. 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.
Wed 7/299:20 pm
SEA
- PHL
Nonstop5h 09m
Delta
Fri 8/77:00 pm
PHL
- SEA
1 stop7h 59m
Delta
Deal found 5/22![Delta logo]()
$339
This Delta deal was found by Cheapflights users on 5/22. 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 8/119:29 pm
SEA
- PHL
Nonstop5h 11m
Delta
Tue 8/183:29 pm
PHL
- SEA
1 stop9h 31m
Delta
Deal found 5/22![Delta logo]()
$339
This Delta deal was found by Cheapflights users on 5/21. 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.
Wed 7/299:20 pm
SEA
- PHL
Nonstop5h 09m
Delta
Thu 8/67:20 am
PHL
- SEA
1 stop8h 39m
Delta
Deal found 5/21![Delta logo]()
$339
This Delta deal was found by Cheapflights users on 5/20. 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 8/49:53 am
SEA
- PHL
1 stop6h 32m
Delta
Thu 8/137:00 pm
PHL
- SEA
1 stop7h 59m
Delta
Deal found 5/20![Delta logo]()
$349
This Delta deal was found by Cheapflights users on 5/20. 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.
Fri 7/319:45 am
SEA
- PHL
1 stop6h 40m
Delta
Thu 8/67:20 am
PHL
- SEA
1 stop8h 39m
Delta
Deal found 5/20![Delta logo]()
$349
This American Airlines deal was found by Cheapflights users on 5/19. 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.
Thu 7/97:26 am
SEA
- SBY
2 stops11h 37m
American Airlines
Thu 7/166:41 am
SBY
- SEA
1 stop7h 59m
American Airlines
Deal found 5/19![American Airlines logo]()
$906
This American Airlines deal was found by Cheapflights users on 5/19. 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.
Wed 7/87:26 am
SEA
- SBY
2 stops11h 37m
American Airlines
Wed 7/154:33 pm
SBY
- SEA
2 stops11h 24m
American Airlines
Deal found 5/19![American Airlines logo]()
$907
This American Airlines deal was found by Cheapflights users on 5/18. 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 6/197:31 am
SEA
- SBY
2 stops11h 33m
American Airlines
Tue 6/306:40 am
SBY
- SEA
2 stops13h 04m
American Airlines
Deal found 5/18![American Airlines logo]()
$969
Last-minute flights from Seattle to DelawareDiscover last-minute flight deals from Seattle to Delaware. Data last updated May 23, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Delaware. Data last updated May 23, 2026 and is based on user searches.
This Delta deal was found by Cheapflights users on 5/18. 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.
Fri 5/299:20 pm
SEA
- PHL
Nonstop5h 17m
Delta
Tue 6/96:45 pm
PHL
- SEA
Nonstop6h 14m
Delta
Deal found 5/18![Delta logo]()
$337
This Delta deal was found by Cheapflights users on 5/18. 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.
Fri 5/2911:59 pm
SEA
- PHL
1 stop7h 33m
Delta
Mon 6/86:45 pm
PHL
- SEA
Nonstop6h 14m
Delta
Deal found 5/18![Delta logo]()
$347
This Travelocity deal was found by Cheapflights users on 5/18. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/13:19 pm
SEA
- PHL
1 stop11h 18m
Frontier
Tue 6/97:06 pm
PHL
- SEA
1 stop18h 29m
Frontier
Deal found 5/18![Frontier logo]()
$350
This American Airlines deal was found by Cheapflights users on 5/18. 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.
Tue 6/28:10 am
SEA
- SBY
1 stop12h 00m
American Airlines
Thu 1/286:30 am
SBY
- SEA
1 stop18h 37m
American Airlines
Deal found 5/18![American Airlines logo]()
$800
This CheapOair deal was found by Cheapflights users on 5/18. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/87:50 pm
SEA
- PHL
1 stop12h 57m
Frontier
Wed 6/1011:00 am
PHL
- SEA
1 stop26h 35m
Frontier
Deal found 5/18![Frontier logo]()
$340
This Delta deal was found by Cheapflights users on 5/18. 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 6/99:25 am
SEA
- PHL
Nonstop5h 10m
Delta
Sun 6/216:45 pm
PHL
- SEA
Nonstop6h 14m
Delta
Deal found 5/18![Delta logo]()
$333
This Super.com deal was found by Cheapflights users on 5/18. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/103:33 pm
SEA
- PHL
1 stop17h 14m
Frontier
Fri 6/1211:00 am
PHL
- SEA
1 stop26h 35m
Frontier
Deal found 5/18![Frontier logo]()
$342
This Trip.com deal was found by Cheapflights users on 5/19. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/107:41 pm
SEA
- PHL
1 stop13h 06m
Frontier
Mon 6/1511:00 am
PHL
- SEA
1 stop26h 35m
Frontier
Deal found 5/19![Frontier logo]()
$353
This American Airlines deal was found by Cheapflights users on 5/18. 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 6/198:10 am
SEA
- SBY
1 stop12h 00m
American Airlines
Tue 6/306:40 am
SBY
- SEA
1 stop17h 55m
American Airlines
Deal found 5/18![American Airlines logo]()
$758
This Delta deal was found by Cheapflights users on 5/19. 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.
Sat 6/206:00 am
SEA
- PHL
1 stop9h 57m
Delta
Tue 6/236:45 pm
PHL
- SEA
Nonstop6h 14m
Delta
Deal found 5/19![Delta logo]()
$339
This American Airlines deal was found by Cheapflights users on 5/23. 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.
Thu 6/2510:35 pm
SEA
- PHL
Nonstop5h 12m
American Airlines
Fri 7/37:35 pm
PHL
- SEA
Nonstop6h 21m
American Airlines
Deal found 5/23![American Airlines logo]()
$330
This Alaska Airlines deal was found by Cheapflights users on 5/18. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/278:28 am
SEA
- PHL
Nonstop5h 15m
Alaska Airlines
Sat 7/44:26 pm
PHL
- SEA
Nonstop6h 04m
Alaska Airlines
Deal found 5/18![Alaska Airlines logo]()
$329
One-way flights from Seattle to DelawareSearch for one-way flight options from Seattle to Delaware. Find affordable one-way fares based on user searches. Data last updated May 23, 2026.
Search for one-way flight options from Seattle to Delaware. Find affordable one-way fares based on user searches. Data last updated May 23, 2026.
This Delta deal was found by Cheapflights users on 5/21. 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.
Wed 7/159:20 pm
SEA
- PHL
Nonstop5h 09m
Delta
Deal found 5/21![Delta logo]()
$165
This Delta deal was found by Cheapflights users on 5/19. 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.
Fri 5/299:20 pm
SEA
- PHL
Nonstop5h 17m
Delta
Deal found 5/19![Delta logo]()
$169
This Kiwi.com deal was found by Cheapflights users on 5/20. 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.
Tue 6/237:41 pm
SEA
- PHL
2 stops23h 48m
Frontier
Deal found 5/20![Frontier logo]()
$170
This United Airlines deal was found by Cheapflights users on 5/20. 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.
Wed 7/1511:20 pm
SEA
- PHL
1 stop7h 25m
United Airlines
Deal found 5/20![United Airlines logo]()
$175
This Expedia deal was found by Cheapflights users on 5/23. 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 9/78:59 pm
SEA
- PHL
1 stop15h 46m
Alaska Airlines
Deal found 5/23![Alaska Airlines logo]()
$180
This Frontier deal was found by Cheapflights users on 5/23. 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.
Wed 7/17:41 pm
SEA
- PHL
1 stop13h 06m
Frontier
Deal found 5/23![Frontier logo]()
$181
This Kiwi.com deal was found by Cheapflights users on 5/23. 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 7/308:53 pm
SEA
- PHL
2 stops16h 55m
Multiple Airlines
Deal found 5/23![Multiple Airlines logo]()
$182
This United Airlines deal was found by Cheapflights users on 5/18. 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.
Wed 6/177:00 am
SEA
- PHL
1 stop9h 18m
United Airlines
Deal found 5/18![United Airlines logo]()
$185
This United Airlines deal was found by Cheapflights users on 5/19. 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 6/910:29 am
SEA
- PHL
2 stops11h 30m
United Airlines
Deal found 5/19![United Airlines logo]()
$190
This Southwest deal was found by Cheapflights users on 5/21. 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 8/65:15 am
SEA
- PHL
1 stop9h 40m
Southwest
Deal found 5/21![Southwest logo]()
$191
This United Airlines deal was found by Cheapflights users on 5/23. 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 7/210:29 am
SEA
- PHL
1 stop11h 54m
United Airlines
Deal found 5/23![United Airlines logo]()
$192
This Kiwi.com deal was found by Cheapflights users on 5/18. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/278:12 pm
SEA
- SBY
2 stops44h 19m
Multiple Airlines
Deal found 5/18![Multiple Airlines logo]()
$453
Find flight deals from Seattle to Delaware
Keep the following information in mind while searching for Seattle to Delaware flight deals. Data was last updated May 23, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $329 (Delta) |
One-way from | $165 (Delta) |
Popular in | December |
Cheapest in | October |
Average price | $435 |
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 May 23, 2026.
Use the filters below to find and compare flights from Seattle to Delaware that are best for you.
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SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Tue 8/4
9:29 pm-5:40 am
Nonstop5h 11m
Philadelphia
Tue 8/11
7:00 am-9:56 am
Nonstop5h 56m
$329
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Mon 8/24
9:29 pm-5:40 am
Nonstop5h 11m
Philadelphia
Thu 8/27
7:00 pm-11:59 pm
1 stop7h 59m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Fri 8/7
6:09 pm-6:05 am
1 stop8h 56m
Philadelphia
Sat 8/29
7:00 am-9:56 am
Nonstop5h 56m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 7/29
9:20 pm-5:29 am
Nonstop5h 09m
Philadelphia
Fri 8/7
7:00 pm-11:59 pm
1 stop7h 59m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Tue 8/11
9:29 pm-5:40 am
Nonstop5h 11m
Philadelphia
Tue 8/18
3:29 pm-10:00 pm
1 stop9h 31m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 7/29
9:20 pm-5:29 am
Nonstop5h 09m
Philadelphia
Thu 8/6
7:20 am-12:59 pm
1 stop8h 39m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Tue 8/4
9:53 am-7:25 pm
1 stop6h 32m
Philadelphia
Thu 8/13
7:00 pm-11:59 pm
1 stop7h 59m
$349
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Fri 7/31
9:45 am-7:25 pm
1 stop6h 40m
Philadelphia
Thu 8/6
7:20 am-12:59 pm
1 stop8h 39m
$349
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Thu 10/1
5:00 am-3:50 pm
1 stop7h 50m
Philadelphia
Mon 10/5
12:20 pm-8:25 pm
2 stops11h 05m
$354
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 6/24
12:50 pm-11:30 pm
1 stop7h 40m
Philadelphia
Sun 6/28
6:30 pm-1:15 am
1 stop9h 45m
$359
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Best time to book a flight from Seattle to Delaware
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SEA-PHL
SEA-SBY
Estimated round-trip price
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SEA-USDE
SEA-PHL
SEA-SBY
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