$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 10/12. Fares are subject to change and may not be available on all flights or dates of travel.
SEA ā ILG
Aug 15 ā Aug 221
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 āFind dealsā2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
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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 July 16, 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 July 16, 2026.
This Alaska Airlines deal was found by Cheapflights users on 7/12. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Alaska Airlines is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 9/29:27 pm
SEA
- PHL
Nonstop5h 13m
Alaska Airlines
Fri 9/256:59 pm
PHL
- SEA
Nonstop5h 52m
Alaska Airlines
Deal found 7/12![Alaska Airlines logo]()
$329
This Kiwi.com deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Mon 8/172:22 pm
SEA
- PHL
1 stop12h 17m
Frontier
Fri 8/218:00 am
PHL
- SEA
1 stop29h 39m
Frontier
Deal found 7/15![Frontier logo]()
$330
This Kiwi.com deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/132:22 pm
SEA
- PHL
1 stop12h 17m
Frontier
Thu 8/208:37 pm
PHL
- SEA
1 stop15h 42m
Frontier
Deal found 7/11![Frontier logo]()
$331
This Kiwi.com deal was found by Cheapflights users on 7/12. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sun 9/67:06 pm
SEA
- PHL
1 stop7h 33m
Multiple Airlines
Mon 9/214:48 pm
PHL
- SEA
1 stop8h 51m
Multiple Airlines
Deal found 7/12![Multiple Airlines logo]()
$332
This Kiwi.com deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sat 8/158:13 pm
SEA
- PHL
1 stop30h 47m
Multiple Airlines
Tue 8/187:33 am
PHL
- SEA
Nonstop5h 59m
Multiple Airlines
Deal found 7/11![Multiple Airlines logo]()
$333
This Southwest deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Southwest is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/277:00 am
SEA
- PHL
2 stops11h 05m
Southwest
Mon 8/312:05 pm
PHL
- SEA
2 stops9h 40m
Southwest
Deal found 7/15![Southwest logo]()
$334
This Kiwi.com deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/57:06 pm
SEA
- PHL
1 stop13h 43m
Frontier
Tue 8/118:30 am
PHL
- SEA
2 stops27h 34m
Frontier
Deal found 7/15![Frontier logo]()
$335
This CheapOair deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure CheapOair is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sun 7/198:53 pm
SEA
- PHL
1 stop30h 07m
Frontier
Tue 7/2811:06 am
PHL
- SEA
1 stop26h 33m
Frontier
Deal found 7/15![Frontier logo]()
$336
This Kiwi.com deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/128:13 pm
SEA
- PHL
1 stop30h 47m
Multiple Airlines
Tue 8/187:33 am
PHL
- SEA
Nonstop5h 59m
Multiple Airlines
Deal found 7/11![Multiple Airlines logo]()
$337
This Kiwi.com deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/132:22 pm
SEA
- PHL
1 stop12h 17m
Frontier
Fri 8/218:37 pm
PHL
- SEA
1 stop15h 42m
Frontier
Deal found 7/11![Frontier logo]()
$338
This Delta deal was found by Cheapflights users on 7/13. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 9/25:30 am
SEA
- PHL
1 stop8h 03m
Delta
Mon 9/77:05 am
PHL
- SEA
Nonstop5h 56m
Delta
Deal found 7/13![Delta logo]()
$339
This Southwest deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Southwest is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Fri 8/217:00 am
SEA
- PHL
2 stops11h 05m
Southwest
Mon 8/312:05 pm
PHL
- SEA
2 stops9h 40m
Southwest
Deal found 7/14![Southwest logo]()
$340
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 July 16, 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 July 16, 2026.
This Delta deal was found by Cheapflights users on 7/12. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 9/179:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Mon 9/217:05 am
PHL
- SEA
Nonstop5h 51m
Delta
Deal found 7/12![Delta logo]()
$329
This Alaska Airlines deal was found by Cheapflights users on 7/13. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Alaska Airlines is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/279:27 pm
SEA
- PHL
Nonstop5h 13m
Alaska Airlines
Thu 9/36:59 pm
PHL
- SEA
Nonstop5h 52m
Alaska Airlines
Deal found 7/13![Alaska Airlines logo]()
$332
This Southwest deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Southwest is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 9/96:40 am
SEA
- PHL
2 stops8h 20m
Southwest
Sun 9/135:05 pm
PHL
- SEA
1 stop9h 05m
Southwest
Deal found 7/14![Southwest logo]()
$335
This United Airlines deal was found by Cheapflights users on 7/13. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure United Airlines is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/126:15 pm
SEA
- PHL
2 stops12h 28m
United Airlines
Wed 8/195:01 pm
PHL
- SEA
1 stop8h 42m
United Airlines
Deal found 7/13![United Airlines logo]()
$432
This Delta deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Tue 9/2211:59 pm
SEA
- PHL
1 stop7h 48m
Delta
Thu 10/17:05 am
PHL
- SEA
Nonstop5h 51m
Delta
Deal found 7/15![Delta logo]()
$339
This American Airlines deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure American Airlines is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sat 8/156:25 am
SEA
- SBY
1 stop10h 46m
American Airlines
Sat 8/226:41 am
SBY
- SEA
1 stop8h 05m
American Airlines
Deal found 7/15![American Airlines logo]()
$743
This Southwest deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Southwest is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 11/255:30 am
SEA
- PHL
2 stops11h 25m
Southwest
Tue 12/17:25 am
PHL
- SEA
1 stop8h 30m
Southwest
Deal found 7/11![Southwest logo]()
$376
This Delta deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Mon 11/21:35 pm
SEA
- PHL
1 stop7h 09m
Delta
Fri 11/63:00 pm
PHL
- SEA
1 stop8h 50m
Delta
Deal found 7/11![Delta logo]()
$349
This Southwest deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Southwest is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Fri 8/287:00 am
SEA
- PHL
2 stops11h 05m
Southwest
Sun 9/69:00 am
PHL
- SEA
2 stops11h 45m
Southwest
Deal found 7/11![Southwest logo]()
$383
This Delta deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Fri 8/1411:10 pm
SEA
- PHL
1 stop6h 26m
Delta
Thu 8/207:00 pm
PHL
- SEA
1 stop7h 59m
Delta
Deal found 7/15![Delta logo]()
$359
This Delta deal was found by Cheapflights users on 7/12. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Tue 8/119:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Tue 8/187:05 am
PHL
- SEA
Nonstop5h 56m
Delta
Deal found 7/12![Delta logo]()
$403
This Delta deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Fri 8/1411:10 pm
SEA
- PHL
1 stop6h 26m
Delta
Fri 8/217:05 am
PHL
- SEA
Nonstop5h 56m
Delta
Deal found 7/15![Delta logo]()
$423
This American Airlines deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure American Airlines is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/125:10 am
SEA
- SBY
1 stop8h 05m
American Airlines
Tue 8/186:41 am
SBY
- SEA
1 stop8h 09m
American Airlines
Deal found 7/14![American Airlines logo]()
$743
This American Airlines deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure American Airlines is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/128:10 am
SEA
- SBY
1 stop11h 48m
American Airlines
Wed 8/196:41 am
SBY
- SEA
1 stop19h 15m
American Airlines
Deal found 7/14![American Airlines logo]()
$780
Last-minute flights from Seattle to DelawareDiscover last-minute flight deals from Seattle to Delaware. Data last updated July 16, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Delaware. Data last updated July 16, 2026 and is based on user searches.
This CheapOair deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure CheapOair is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sun 7/198:53 pm
SEA
- PHL
1 stop30h 07m
Frontier
Tue 7/2811:06 am
PHL
- SEA
1 stop26h 33m
Frontier
Deal found 7/15![Frontier logo]()
$336
This Kiwi.com deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/57:06 pm
SEA
- PHL
1 stop13h 43m
Frontier
Tue 8/118:30 am
PHL
- SEA
2 stops27h 34m
Frontier
Deal found 7/15![Frontier logo]()
$335
This Kiwi.com deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/128:13 pm
SEA
- PHL
1 stop30h 47m
Multiple Airlines
Tue 8/187:33 am
PHL
- SEA
Nonstop5h 59m
Multiple Airlines
Deal found 7/11![Multiple Airlines logo]()
$337
This American Airlines deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure American Airlines is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/125:10 am
SEA
- SBY
1 stop8h 05m
American Airlines
Tue 8/186:41 am
SBY
- SEA
1 stop8h 09m
American Airlines
Deal found 7/14![American Airlines logo]()
$743
This Kiwi.com deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/132:22 pm
SEA
- PHL
1 stop12h 17m
Frontier
Thu 8/208:37 pm
PHL
- SEA
1 stop15h 42m
Frontier
Deal found 7/11![Frontier logo]()
$331
This Kiwi.com deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/132:22 pm
SEA
- PHL
1 stop12h 17m
Frontier
Fri 8/218:37 pm
PHL
- SEA
1 stop15h 42m
Frontier
Deal found 7/11![Frontier logo]()
$338
This Kiwi.com deal was found by Cheapflights users on 7/11. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sat 8/158:13 pm
SEA
- PHL
1 stop30h 47m
Multiple Airlines
Tue 8/187:33 am
PHL
- SEA
Nonstop5h 59m
Multiple Airlines
Deal found 7/11![Multiple Airlines logo]()
$333
This Kiwi.com deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Mon 8/172:22 pm
SEA
- PHL
1 stop12h 17m
Frontier
Fri 8/218:00 am
PHL
- SEA
1 stop29h 39m
Frontier
Deal found 7/15![Frontier logo]()
$330
This Southwest deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Southwest is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Fri 8/217:00 am
SEA
- PHL
2 stops11h 05m
Southwest
Mon 8/312:05 pm
PHL
- SEA
2 stops9h 40m
Southwest
Deal found 7/14![Southwest logo]()
$340
This Southwest deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Southwest is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/277:00 am
SEA
- PHL
2 stops11h 05m
Southwest
Mon 8/312:05 pm
PHL
- SEA
2 stops9h 40m
Southwest
Deal found 7/15![Southwest logo]()
$334
This Delta deal was found by Cheapflights users on 7/13. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/276:09 pm
SEA
- PHL
1 stop8h 56m
Delta
Mon 8/317:05 am
PHL
- SEA
Nonstop5h 56m
Delta
Deal found 7/13![Delta logo]()
$339
This Alaska Airlines deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Alaska Airlines is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Fri 8/289:27 pm
SEA
- PHL
Nonstop5h 13m
Alaska Airlines
Fri 9/46:59 pm
PHL
- SEA
Nonstop5h 52m
Alaska Airlines
Deal found 7/14![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 July 16, 2026.
Search for one-way flight options from Seattle to Delaware. Find affordable one-way fares based on user searches. Data last updated July 16, 2026.
This Delta deal was found by Cheapflights users on 7/13. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 9/109:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Deal found 7/13![Delta logo]()
$165
This Kiwi.com deal was found by Cheapflights users on 7/16. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Mon 9/289:16 pm
SEA
- PHL
2 stops22h 55m
Frontier
Deal found 7/16![Frontier logo]()
$166
This Frontier deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Frontier is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Wed 8/127:06 pm
SEA
- PHL
1 stop13h 43m
Frontier
Deal found 7/15![Frontier logo]()
$167
This Kiwi.com deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 10/157:41 pm
SEA
- PHL
2 stops24h 40m
Frontier
Deal found 7/15![Frontier logo]()
$168
This Kiwi.com deal was found by Cheapflights users on 7/13. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sat 8/158:13 pm
SEA
- PHL
1 stop30h 47m
Frontier
Deal found 7/13![Frontier logo]()
$169
This Delta deal was found by Cheapflights users on 7/16. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Fri 10/169:31 pm
SEA
- PHL
Nonstop5h 14m
Delta
Deal found 7/16![Delta logo]()
$170
This Kiwi.com deal was found by Cheapflights users on 7/13. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Fri 9/119:16 pm
SEA
- PHL
2 stops17h 59m
Frontier
Deal found 7/13![Frontier logo]()
$171
This Super.com deal was found by Cheapflights users on 7/12. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Super.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 7/307:06 pm
SEA
- PHL
1 stop7h 33m
Frontier
Deal found 7/12![Frontier logo]()
$172
This Southwest deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Southwest is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sat 9/55:00 am
SEA
- PHL
2 stops12h 45m
Southwest
Deal found 7/14![Southwest logo]()
$174
This Delta deal was found by Cheapflights users on 7/13. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Delta is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sun 10/117:59 pm
SEA
- PHL
1 stop7h 06m
Delta
Deal found 7/13![Delta logo]()
$175
This Kiwi.com deal was found by Cheapflights users on 7/15. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure Kiwi.com is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Sun 9/137:00 am
SEA
- PHL
1 stop19h 36m
Frontier
Deal found 7/15![Frontier logo]()
$176
This KAYAK deal was found by Cheapflights users on 7/14. Clicking the āPick Datesā button in this card will allow you to select your dates and further customize your flight criteria. From there, click āFind dealsā, make sure KAYAK is selected, and click āCompare selectedā under the list of providers to see comparable flight deals.
Thu 8/66:25 am
SEA
- SBY
1 stop10h 46m
American Airlines
Deal found 7/14![American Airlines logo]()
$729
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 July 16, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $329 (Alaska Airlines) |
One-way from | $165 (Delta) |
Popular in | December |
Cheapest in | October |
Average price | $417 |
Cheapflights Fare Finder
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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 July 16, 2026.
Use the filters below to find and compare flights from Seattle to Delaware that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Thu 9/17
9:30 pm-5:50 am
Nonstop5h 20m
Philadelphia
Mon 9/21
7:05 am-9:56 am
Nonstop5h 51m
$329
Quickest round-trip
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Thu 8/27
9:27 pm-5:40 am
Nonstop5h 13m
Philadelphia
Thu 9/3
6:59 pm-9:51 pm
Nonstop5h 52m
$332
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 9/9
6:40 am-6:00 pm
2 stops8h 20m
Philadelphia
Sun 9/13
5:05 pm-11:10 pm
1 stop9h 05m
$335
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Tue 9/22
11:59 pm-10:47 am
1 stop7h 48m
Philadelphia
Thu 10/1
7:05 am-9:56 am
Nonstop5h 51m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Mon 11/2
1:35 pm-11:44 pm
1 stop7h 09m
Philadelphia
Fri 11/6
3:00 pm-8:50 pm
1 stop8h 50m
$349
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Fri 8/14
11:10 pm-8:36 am
1 stop6h 26m
Philadelphia
Thu 8/20
7:00 pm-11:59 pm
1 stop7h 59m
$359
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 11/25
5:30 am-7:55 pm
2 stops11h 25m
Philadelphia
Tue 12/1
7:25 am-12:55 pm
1 stop8h 30m
$376
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Fri 8/28
7:00 am-9:05 pm
2 stops11h 05m
Philadelphia
Sun 9/6
9:00 am-5:45 pm
2 stops11h 45m
$383
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Tue 8/11
9:30 pm-5:50 am
Nonstop5h 20m
Philadelphia
Tue 8/18
7:05 am-10:01 am
Nonstop5h 56m
$403
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Fri 8/14
11:10 pm-8:36 am
1 stop6h 26m
Philadelphia
Fri 8/21
7:05 am-10:01 am
Nonstop5h 56m
$423
Showing 1-10 of 26 resultsSorted by cheapest first
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.
SEA-PHL
SEA-SBY
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
SEA-USDE
SEA-PHL
SEA-SBY
No data available for this route at this time. Please check back soon.
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