$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 9/15. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ILG
Jul 21 — Jul 281
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to Delaware with Cheapflights
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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 June 21, 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 June 21, 2026.
This Delta deal was found by Cheapflights users on 6/21. 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 9/29:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Fri 9/117:05 am
PHL
- SEA
Nonstop5h 51m
Delta
Deal found 6/21![Delta logo]()
$329
This CheapOair deal was found by Cheapflights users on 6/20. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/43:33 pm
SEA
- PHL
1 stop17h 16m
Frontier
Sun 7/128:37 pm
PHL
- SEA
1 stop15h 40m
Frontier
Deal found 6/20![Frontier logo]()
$330
This Trip.com deal was found by Cheapflights users on 6/17. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/158:13 pm
SEA
- PHL
1 stop30h 47m
Multiple Airlines
Wed 7/224:26 pm
PHL
- SEA
Nonstop6h 04m
Multiple Airlines
Deal found 6/17![Multiple Airlines logo]()
$331
This Expedia deal was found by Cheapflights users on 6/17. 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.
Tue 7/148:13 pm
SEA
- PHL
1 stop30h 47m
Multiple Airlines
Tue 7/214:26 pm
PHL
- SEA
Nonstop6h 04m
Multiple Airlines
Deal found 6/17![Multiple Airlines logo]()
$332
This Booking.com deal was found by Cheapflights users on 6/17. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/211:03 am
SEA
- PHL
1 stop19h 13m
Frontier
Mon 7/68:37 pm
PHL
- SEA
1 stop15h 40m
Frontier
Deal found 6/17![Frontier logo]()
$333
This Kiwi.com deal was found by Cheapflights users on 6/20. 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 6/308:12 pm
SEA
- PHL
1 stop31h 15m
Frontier
Sun 7/58:37 pm
PHL
- SEA
1 stop17h 43m
Frontier
Deal found 6/20![Frontier logo]()
$334
This United Airlines deal was found by Cheapflights users on 6/19. 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.
Fri 9/1811:00 pm
SEA
- PHL
1 stop8h 02m
United Airlines
Sun 9/206:00 am
PHL
- SEA
1 stop9h 20m
United Airlines
Deal found 6/19![United Airlines logo]()
$335
This Expedia deal was found by Cheapflights users on 6/21. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/27:06 pm
SEA
- PHL
1 stop7h 33m
Frontier
Fri 8/78:37 pm
PHL
- SEA
1 stop15h 27m
Frontier
Deal found 6/21![Frontier logo]()
$336
This Alaska Airlines deal was found by Cheapflights users on 6/20. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/18:28 am
SEA
- PHL
Nonstop5h 15m
Alaska Airlines
Sat 7/47:33 am
PHL
- SEA
Nonstop5h 59m
Alaska Airlines
Deal found 6/20![Alaska Airlines logo]()
$337
This Delta deal was found by Cheapflights users on 6/17. 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.
Thu 11/129:50 pm
SEA
- PHL
Nonstop5h 13m
Delta
Sun 11/156:40 pm
PHL
- SEA
1 stop8h 31m
Delta
Deal found 6/17![Delta logo]()
$338
This Delta deal was found by Cheapflights users on 6/21. 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 9/29:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Wed 9/96:59 pm
PHL
- SEA
1 stop7h 56m
Delta
Deal found 6/21![Delta logo]()
$339
This Gotogate deal was found by Cheapflights users on 6/17. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/33:33 pm
SEA
- PHL
1 stop11h 05m
Frontier
Mon 7/68:37 pm
PHL
- SEA
1 stop15h 40m
Frontier
Deal found 6/17![Frontier 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 June 21, 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 June 21, 2026.
This Delta deal was found by Cheapflights users on 6/18. 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.
Mon 9/289:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Thu 10/17:05 am
PHL
- SEA
Nonstop5h 51m
Delta
Deal found 6/18![Delta logo]()
$329
This Southwest deal was found by Cheapflights users on 6/16. 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.
Wed 8/511:05 pm
SEA
- PHL
2 stops11h 10m
Southwest
Tue 8/1110:45 am
PHL
- SEA
1 stop10h 10m
Southwest
Deal found 6/16![Southwest logo]()
$354
This Alaska Airlines deal was found by Cheapflights users on 6/19. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/229:27 pm
SEA
- PHL
Nonstop5h 13m
Alaska Airlines
Wed 9/234:48 pm
PHL
- SEA
1 stop8h 51m
Alaska Airlines
Deal found 6/19![Alaska Airlines logo]()
$369
This Delta deal was found by Cheapflights users on 6/19. 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 9/189:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Sun 9/207:05 am
PHL
- SEA
Nonstop5h 51m
Delta
Deal found 6/19![Delta logo]()
$329
This Delta deal was found by Cheapflights users on 6/20. 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.
Thu 11/129:50 pm
SEA
- PHL
Nonstop5h 13m
Delta
Sun 11/156:40 pm
PHL
- SEA
1 stop8h 31m
Delta
Deal found 6/20![Delta logo]()
$338
This Southwest deal was found by Cheapflights users on 6/16. 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.
Wed 8/197:10 am
SEA
- PHL
2 stops10h 25m
Southwest
Sun 8/236:20 am
PHL
- SEA
1 stop9h 55m
Southwest
Deal found 6/16![Southwest logo]()
$384
This American Airlines deal was found by Cheapflights users on 6/20. 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.
Mon 8/108:10 am
SEA
- SBY
1 stop11h 48m
American Airlines
Sun 8/166:41 am
SBY
- SEA
1 stop19h 15m
American Airlines
Deal found 6/20![American Airlines logo]()
$774
This Delta deal was found by Cheapflights users on 6/17. 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.
Thu 10/221:45 pm
SEA
- PHL
1 stop8h 06m
Delta
Sun 10/257:05 am
PHL
- SEA
Nonstop6h 19m
Delta
Deal found 6/17![Delta logo]()
$339
This Southwest deal was found by Cheapflights users on 6/16. 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.
Fri 7/2411:10 am
SEA
- PHL
2 stops10h 35m
Southwest
Mon 8/311:20 am
PHL
- SEA
1 stop11h 25m
Southwest
Deal found 6/16![Southwest logo]()
$395
This Delta deal was found by Cheapflights users on 6/18. 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.
Thu 10/157:35 pm
SEA
- PHL
1 stop7h 06m
Delta
Sun 10/187:05 am
PHL
- SEA
Nonstop6h 19m
Delta
Deal found 6/18![Delta logo]()
$339
This Southwest deal was found by Cheapflights users on 6/20. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/611:05 pm
SEA
- PHL
1 stop9h 05m
Southwest
Sun 8/96:20 am
PHL
- SEA
2 stops10h 20m
Southwest
Deal found 6/20![Southwest logo]()
$398
This Delta deal was found by Cheapflights users on 6/20. 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.
Wed 9/29:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Sat 9/53:55 pm
PHL
- SEA
1 stop11h 02m
Delta
Deal found 6/20![Delta logo]()
$339
This American Airlines deal was found by Cheapflights users on 6/16. 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.
Sat 8/110:47 am
SEA
- SBY
1 stop8h 16m
American Airlines
Sat 8/812:35 pm
SBY
- SEA
1 stop9h 13m
American Airlines
Deal found 6/16![American Airlines logo]()
$853
This American Airlines deal was found by Cheapflights users on 6/16. 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.
Sat 8/110:47 am
SEA
- SBY
1 stop8h 16m
American Airlines
Wed 8/56:41 am
SBY
- SEA
1 stop8h 09m
American Airlines
Deal found 6/16![American Airlines logo]()
$935
This American Airlines deal was found by Cheapflights users on 6/16. 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.
Sat 8/110:47 am
SEA
- SBY
1 stop8h 16m
American Airlines
Tue 8/116:41 am
SBY
- SEA
2 stops11h 15m
American Airlines
Deal found 6/16![American Airlines logo]()
$941
This American Airlines deal was found by Cheapflights users on 6/16. 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.
Sat 8/16:15 pm
SEA
- SBY
2 stops13h 43m
American Airlines
Mon 8/104:40 pm
SBY
- SEA
1 stop8h 19m
American Airlines
Deal found 6/16![American Airlines logo]()
$945
This American Airlines deal was found by Cheapflights users on 6/16. 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.
Sun 8/210:47 am
SEA
- SBY
1 stop8h 16m
American Airlines
Sat 8/86:41 am
SBY
- SEA
2 stops11h 15m
American Airlines
Deal found 6/16![American Airlines logo]()
$945
This American Airlines deal was found by Cheapflights users on 6/16. 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.
Sat 8/110:47 am
SEA
- SBY
1 stop8h 16m
American Airlines
Sun 8/94:41 pm
SBY
- SEA
1 stop9h 08m
American Airlines
Deal found 6/16![American Airlines logo]()
$1,016
This American Airlines deal was found by Cheapflights users on 6/19. 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.
Sat 7/45:10 am
SEA
- SBY
1 stop7h 58m
American Airlines
Wed 7/86:41 am
SBY
- SEA
1 stop7h 59m
American Airlines
Deal found 6/19![American Airlines logo]()
$1,031
This KAYAK deal was found by Cheapflights users on 6/18. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/139:35 pm
SEA
- SBY
1 stop10h 23m
American Airlines
Fri 7/176:00 am
SBY
- SEA
1 stop9h 07m
American Airlines
Deal found 6/18![American Airlines logo]()
$1,101
Last-minute flights from Seattle to DelawareDiscover last-minute flight deals from Seattle to Delaware. Data last updated June 21, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Delaware. Data last updated June 21, 2026 and is based on user searches.
This Trip.com deal was found by Cheapflights users on 6/17. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/237:41 pm
SEA
- PHL
1 stop13h 06m
Frontier
Thu 6/2511:00 am
PHL
- SEA
1 stop26h 35m
Frontier
Deal found 6/17![Frontier logo]()
$339
This Kiwi.com deal was found by Cheapflights users on 6/20. 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 6/308:12 pm
SEA
- PHL
1 stop31h 15m
Frontier
Sun 7/58:37 pm
PHL
- SEA
1 stop17h 43m
Frontier
Deal found 6/20![Frontier logo]()
$334
This Alaska Airlines deal was found by Cheapflights users on 6/20. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/18:28 am
SEA
- PHL
Nonstop5h 15m
Alaska Airlines
Sat 7/47:33 am
PHL
- SEA
Nonstop5h 59m
Alaska Airlines
Deal found 6/20![Alaska Airlines logo]()
$337
This Expedia deal was found by Cheapflights users on 6/17. 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.
Wed 7/17:41 pm
SEA
- PHL
1 stop13h 06m
Multiple Airlines
Sat 7/47:33 am
PHL
- SEA
Nonstop5h 59m
Multiple Airlines
Deal found 6/17![Multiple Airlines logo]()
$338
This American Airlines deal was found by Cheapflights users on 6/17. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/110:50 am
SEA
- SBY
1 stop8h 14m
American Airlines
Sat 7/46:00 am
SBY
- SEA
1 stop9h 07m
American Airlines
Deal found 6/17![American Airlines logo]()
$743
This Booking.com deal was found by Cheapflights users on 6/17. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/211:03 am
SEA
- PHL
1 stop19h 13m
Frontier
Mon 7/68:37 pm
PHL
- SEA
1 stop15h 40m
Frontier
Deal found 6/17![Frontier logo]()
$333
This Gotogate deal was found by Cheapflights users on 6/17. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/33:33 pm
SEA
- PHL
1 stop11h 05m
Frontier
Mon 7/68:37 pm
PHL
- SEA
1 stop15h 40m
Frontier
Deal found 6/17![Frontier logo]()
$340
This CheapOair deal was found by Cheapflights users on 6/20. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/43:33 pm
SEA
- PHL
1 stop17h 16m
Frontier
Sun 7/128:37 pm
PHL
- SEA
1 stop15h 40m
Frontier
Deal found 6/20![Frontier logo]()
$330
This Expedia deal was found by Cheapflights users on 6/17. 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.
Tue 7/148:13 pm
SEA
- PHL
1 stop30h 47m
Multiple Airlines
Tue 7/214:26 pm
PHL
- SEA
Nonstop6h 04m
Multiple Airlines
Deal found 6/17![Multiple Airlines logo]()
$332
This Trip.com deal was found by Cheapflights users on 6/17. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/158:13 pm
SEA
- PHL
1 stop30h 47m
Multiple Airlines
Wed 7/224:26 pm
PHL
- SEA
Nonstop6h 04m
Multiple Airlines
Deal found 6/17![Multiple Airlines logo]()
$331
This Kiwi.com deal was found by Cheapflights users on 6/17. 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 7/177:06 pm
SEA
- PHL
1 stop7h 33m
Multiple Airlines
Tue 7/217:33 am
PHL
- SEA
Nonstop5h 59m
Multiple Airlines
Deal found 6/17![Multiple Airlines logo]()
$335
This Delta deal was found by Cheapflights users on 6/17. 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.
Wed 7/229:20 pm
SEA
- PHL
Nonstop5h 09m
Delta
Tue 7/287:05 am
PHL
- SEA
Nonstop5h 56m
Delta
Deal found 6/17![Delta 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 June 21, 2026.
Search for one-way flight options from Seattle to Delaware. Find affordable one-way fares based on user searches. Data last updated June 21, 2026.
This Delta deal was found by Cheapflights users on 6/21. 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.
Tue 9/159:30 pm
SEA
- PHL
Nonstop5h 20m
Delta
Deal found 6/21![Delta logo]()
$165
This Trip.com deal was found by Cheapflights users on 6/20. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/48:13 pm
SEA
- PHL
2 stops13h 09m
Frontier
Deal found 6/20![Frontier logo]()
$166
This United Airlines deal was found by Cheapflights users on 6/18. 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 7/155:00 am
SEA
- PHL
1 stop10h 57m
United Airlines
Deal found 6/18![United Airlines logo]()
$167
This United Airlines deal was found by Cheapflights users on 6/16. 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.
Mon 8/2411:04 pm
SEA
- PHL
1 stop7h 39m
United Airlines
Deal found 6/16![United Airlines logo]()
$168
This Delta deal was found by Cheapflights users on 6/20. 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 7/39:25 am
SEA
- PHL
Nonstop5h 10m
Delta
Deal found 6/20![Delta logo]()
$169
This American Airlines deal was found by Cheapflights users on 6/17. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/69:58 pm
SEA
- PHL
Nonstop5h 18m
American Airlines
Deal found 6/17![American Airlines logo]()
$170
This Super.com deal was found by Cheapflights users on 6/21. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/107:06 pm
SEA
- PHL
1 stop7h 33m
Frontier
Deal found 6/21![Frontier logo]()
$172
This Kiwi.com deal was found by Cheapflights users on 6/19. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/207:06 pm
SEA
- PHL
2 stops33h 09m
Frontier
Deal found 6/19![Frontier logo]()
$173
This Delta deal was found by Cheapflights users on 6/18. 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.
Thu 9/177:59 pm
SEA
- PHL
1 stop7h 06m
Delta
Deal found 6/18![Delta logo]()
$175
This Kiwi.com deal was found by Cheapflights users on 6/20. 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 8/187:06 pm
SEA
- PHL
2 stops14h 20m
Frontier
Deal found 6/20![Frontier logo]()
$176
This Super.com deal was found by Cheapflights users on 6/16. 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.
Tue 7/218:13 pm
SEA
- PHL
1 stop30h 47m
Frontier
Deal found 6/16![Frontier logo]()
$177
This Kiwi.com deal was found by Cheapflights users on 6/19. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/149:16 pm
SEA
- SBY
3 stops43h 10m
Multiple Airlines
Deal found 6/19![Multiple Airlines logo]()
$240
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 June 21, 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 | $452 |
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 June 21, 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
Quickest round-trip
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Mon 9/28
9:30 pm-5:50 am
Nonstop5h 20m
Philadelphia
Thu 10/1
7:05 am-9:56 am
Nonstop5h 51m
$329
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Fri 9/18
9:30 pm-5:50 am
Nonstop5h 20m
Philadelphia
Sun 9/20
7:05 am-9:56 am
Nonstop5h 51m
$329
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Thu 11/12
9:50 pm-6:03 am
Nonstop5h 13m
Philadelphia
Sun 11/15
6:40 pm-12:11 am
1 stop8h 31m
$338
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Thu 10/22
1:45 pm-12:51 am
1 stop8h 06m
Philadelphia
Sun 10/25
7:05 am-10:24 am
Nonstop6h 19m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Thu 10/15
7:35 pm-5:41 am
1 stop7h 06m
Philadelphia
Sun 10/18
7:05 am-10:24 am
Nonstop6h 19m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 9/2
9:30 pm-5:50 am
Nonstop5h 20m
Philadelphia
Sat 9/5
3:55 pm-11:57 pm
1 stop11h 02m
$339
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 8/5
11:05 pm-1:15 pm
2 stops11h 10m
Philadelphia
Tue 8/11
10:45 am-5:55 pm
1 stop10h 10m
$354
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Tue 9/22
9:27 pm-5:40 am
Nonstop5h 13m
Philadelphia
Wed 9/23
4:48 pm-10:39 pm
1 stop8h 51m
$369
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Wed 8/19
7:10 am-8:35 pm
2 stops10h 25m
Philadelphia
Sun 8/23
6:20 am-1:15 pm
1 stop9h 55m
$384
SeattlePhiladelphia
SEA - PHL
SEAPHL
Seattle/Tacoma Intl
Fri 7/24
11:10 am-12:45 am
2 stops10h 35m
Philadelphia
Mon 8/3
11:20 am-7:45 pm
1 stop11h 25m
$395
Showing 1-10 of 36 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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