$168+ Cheap flights from Seattle (SEA) to Dulles Intl (IAD)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/27. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
Oct 29 — Nov 51
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to Dulles Intl 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
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
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl are usually found in February or April, booked 86 days in advance, depart on a Friday or Thursday and return on a Wednesday
Cheap flight deals from Seattle to Dulles Intl
Cheapest
Best
Last-minute
One-way
Cheapest flights from Seattle to Dulles IntlExplore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 29, 2026.
Explore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 29, 2026.
This Mytrip deal was found by Cheapflights users on 9/28. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/288:09 pm -
2 stops12h 27m
Wed 11/48:05 am -
2 stops28h 40m
Deal found 9/28![Frontier logo]()
$330
This Cheapflightsfares deal was found by Cheapflights users on 9/27. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/189:16 pm -
1 stop30h 04m
Sat 10/246:00 am -
1 stop29h 58m
Deal found 9/27![Frontier logo]()
$334
This Mytrip deal was found by Cheapflights users on 9/28. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2712:14 pm -
2 stops25h 58m
Tue 11/38:05 am -
2 stops34h 07m
Deal found 9/28![Frontier logo]()
$336
This Mytrip deal was found by Cheapflights users on 9/26. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/148:09 pm -
2 stops12h 27m
Tue 11/179:06 pm -
2 stops24h 48m
Deal found 9/26![Frontier logo]()
$337
This Mytrip deal was found by Cheapflights users on 9/25. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/58:09 pm -
2 stops12h 27m
Tue 11/109:06 pm -
2 stops21h 06m
Deal found 9/25![Frontier logo]()
$338
This Mytrip deal was found by Cheapflights users on 9/25. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/68:09 pm -
2 stops18h 03m
Wed 11/118:05 am -
2 stops28h 40m
Deal found 9/25![Frontier logo]()
$343
This SmartFares deal was found by Cheapflights users on 9/24. 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 SmartFares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/89:49 pm -
Nonstop4h 55m
Sun 11/157:05 am -
Nonstop5h 50m
Deal found 9/24![Alaska Airlines logo]()
$348
This Cheapflightsfares deal was found by Cheapflights users on 9/25. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/199:16 pm -
1 stop30h 04m
Thu 10/226:00 am -
1 stop30h 48m
Deal found 9/25![Frontier logo]()
$349
This Mytrip deal was found by Cheapflights users on 9/27. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/64:27 pm -
2 stops28h 16m
Tue 11/109:06 pm -
2 stops21h 06m
Deal found 9/27![Frontier logo]()
$350
This Mytrip deal was found by Cheapflights users on 9/26. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/288:09 pm -
2 stops12h 27m
Fri 11/139:06 pm -
2 stops21h 06m
Deal found 9/26![Frontier logo]()
$351
This Mytrip deal was found by Cheapflights users on 9/28. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/288:09 pm -
2 stops12h 27m
Sun 11/19:06 pm -
2 stops21h 06m
Deal found 9/28![Frontier logo]()
$353
Best flights from Seattle to Dulles IntlDiscover carefully curated flight deals from Seattle to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 29, 2026.
Discover carefully curated flight deals from Seattle to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 29, 2026.
This Delta deal was found by Cheapflights users on 9/27. 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 1/223:55 pm -
Nonstop4h 56m
Tue 1/267:05 am -
Nonstop6h 00m
Deal found 9/27![Delta logo]()
$377
This Alaska Airlines deal was found by Cheapflights users on 9/27. 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.
Fri 1/226:30 am -
1 stop8h 20m
Tue 1/265:30 pm -
Nonstop6h 03m
Deal found 9/27![Alaska Airlines logo]()
$387
This United Airlines deal was found by Cheapflights users on 9/28. 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 10/278:30 am -
1 stop8h 00m
Tue 11/34:10 pm -
1 stop8h 09m
Deal found 9/28![United Airlines logo]()
$457
This Alaska Airlines deal was found by Cheapflights users on 9/28. 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 11/102:53 pm -
2 stops23h 47m
Mon 11/165:17 pm -
Nonstop5h 56m
Deal found 9/28![Alaska Airlines logo]()
$414
This Delta deal was found by Cheapflights users on 9/28. 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 10/221:40 pm -
1 stop8h 02m
Wed 10/287:05 am -
Nonstop5h 51m
Deal found 9/28![Delta logo]()
$448
This Alaska Airlines deal was found by Cheapflights users on 9/27. 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.
Thu 12/178:30 am -
Nonstop4h 58m
Mon 1/115:30 pm -
Nonstop6h 03m
Deal found 9/27![Alaska Airlines logo]()
$437
This Alaska Airlines deal was found by Cheapflights users on 9/26. 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 11/118:07 am -
Nonstop5h 07m
Fri 11/207:00 am -
Nonstop5h 50m
Deal found 9/26![Alaska Airlines logo]()
$437
This Alaska Airlines deal was found by Cheapflights users on 9/25. 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.
Fri 10/239:08 pm -
1 stop17h 42m
Sun 10/257:02 am -
Nonstop5h 42m
Deal found 9/25![Alaska Airlines logo]()
$467
This Alaska Airlines deal was found by Cheapflights users on 9/28. 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.
Fri 12/188:30 am -
Nonstop4h 58m
Mon 1/116:53 pm -
1 stop17h 33m
Deal found 9/28![Alaska Airlines logo]()
$497
Last-minute flights from Seattle to Dulles IntlDiscover last-minute flight deals from Seattle to Dulles Intl. Data last updated September 29, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to Dulles Intl. Data last updated September 29, 2026 and is based on user searches.
This Cheapflightsfares deal was found by Cheapflights users on 9/25. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/169:16 pm -
1 stop30h 04m
Sat 10/246:00 am -
1 stop29h 58m
Deal found 9/25![Frontier logo]()
$354
This Cheapflightsfares deal was found by Cheapflights users on 9/27. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/189:16 pm -
1 stop30h 04m
Sat 10/246:00 am -
1 stop29h 58m
Deal found 9/27![Frontier logo]()
$334
This Cheapflightsfares deal was found by Cheapflights users on 9/25. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/199:16 pm -
1 stop30h 04m
Thu 10/226:00 am -
1 stop30h 48m
Deal found 9/25![Frontier logo]()
$349
This Mytrip deal was found by Cheapflights users on 9/28. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2712:14 pm -
2 stops25h 58m
Tue 11/38:05 am -
2 stops34h 07m
Deal found 9/28![Frontier logo]()
$336
This Mytrip deal was found by Cheapflights users on 9/26. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2712:14 pm -
2 stops25h 58m
Sun 11/19:06 pm -
2 stops21h 06m
Deal found 9/26![Frontier logo]()
$359
This Mytrip deal was found by Cheapflights users on 9/23. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2712:14 pm -
3 stops25h 58m
Wed 10/289:06 pm -
2 stops22h 47m
Deal found 9/23![Multiple Airlines logo]()
$364
This Mytrip deal was found by Cheapflights users on 9/24. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2712:14 pm -
2 stops19h 07m
Fri 10/309:06 pm -
2 stops21h 06m
Deal found 9/24![Frontier logo]()
$366
This Mytrip deal was found by Cheapflights users on 9/28. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/288:09 pm -
2 stops12h 27m
Wed 11/48:05 am -
2 stops28h 40m
Deal found 9/28![Frontier logo]()
$330
This Mytrip deal was found by Cheapflights users on 9/26. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/288:09 pm -
2 stops12h 27m
Fri 11/139:06 pm -
2 stops21h 06m
Deal found 9/26![Frontier logo]()
$351
This Mytrip deal was found by Cheapflights users on 9/28. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/288:09 pm -
2 stops12h 27m
Sun 11/19:06 pm -
2 stops21h 06m
Deal found 9/28![Frontier logo]()
$353
One-way flights from Seattle to Dulles IntlSearch for one-way flight options from Seattle to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated September 29, 2026.
Search for one-way flight options from Seattle to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated September 29, 2026.
This Mytrip deal was found by Cheapflights users on 9/27. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2712:14 pm -
2 stops25h 58m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Frontier logo]()
$168
This Kiwi.com deal was found by Cheapflights users on 9/27. 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 11/29:13 pm -
2 stops40h 59m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Frontier logo]()
$169
This Mytrip deal was found by Cheapflights users on 9/24. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/288:09 pm -
2 stops12h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Frontier logo]()
$175
This Kiwi.com deal was found by Cheapflights users on 9/28. 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 10/199:16 pm -
1 stop30h 04m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/28![Frontier logo]()
$176
This Super.com deal was found by Cheapflights users on 9/26. 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.
Sun 11/229:53 pm -
1 stop28h 17m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/26![Frontier logo]()
$179
This Super.com deal was found by Cheapflights users on 9/27. 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.
Sun 10/189:16 pm -
1 stop30h 04m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Frontier logo]()
$181
This Super.com deal was found by Cheapflights users on 9/24. 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 10/239:16 pm -
1 stop30h 04m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Frontier logo]()
$182
This Cheapflightsfares deal was found by Cheapflights users on 9/27. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/239:53 pm -
1 stop28h 17m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Frontier logo]()
$183
This Kiwi.com deal was found by Cheapflights users on 9/24. 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 10/259:16 pm -
1 stop30h 04m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Frontier logo]()
$184
Find flight deals from Seattle to Dulles Intl
Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Dulles Intl (IAD). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 29, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $330 (Mytrip) |
One-way from | $168 (Mytrip) |
Popular in | January |
Cheapest in | February |
Average price | $377 |
Good round-trip deal | $402 or less |
Good one-way deal | $246 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Seattle to Dulles Intl 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 7,457,451 searches. Data last updated September 29, 2026.
Use the filters below to find and compare flights from Seattle to Washington, D.C. Dulles Intl Airport that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Fri 11/27
8:15 am-4:13 pm
Nonstop4h 58m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$209
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Fri 1/29
3:55 pm-11:51 pm
Nonstop4h 56m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$209
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Mon 2/22
8:25 am-4:26 pm
Nonstop5h 01m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$209
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Tue 12/8
8:15 am-4:15 pm
Nonstop5h 00m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$209
Quickest round-trip
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Thu 11/12
9:49 pm-5:44 am
Nonstop4h 55m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$209
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Thu 11/26
10:36 am-11:21 am
1 stop21h 45m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$218
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Thu 11/26
7:00 am-7:01 pm
1 stop9h 01m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$219
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Wed 10/28
5:05 am-3:44 pm
1 stop7h 39m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$219
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Fri 10/16
5:50 pm-2:50 pm
1 stop18h 00m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$238
SeattleWashington, D.C.
SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl
SEAIAD
Seattle/Tacoma Intl
Fri 10/30
11:25 am-11:16 pm
1 stop8h 51m
Washington, D.C. Dulles Intl
Wed 12/31
12:00 am-9:00 pm
Nonstop0h 00m
$264
Showing 1-10 of 20 resultsSorted by cheapest first
Compare providers for flights from Seattle to Dulles Intl
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Dulles Intl in September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on Seattle-Washington, D.C. Dulles Intl Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Washington, D.C. Dulles Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Washington, D.C. Dulles Intl Airport flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Seattle-Washington, D.C. Dulles Intl Airport flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Washington, D.C. Dulles Intl Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from Seattle to Dulles Intl
Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from Seattle with our price prediction graph.
SEA-IAD
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 Washington, D.C. Dulles Intl Airport
Prices
Airlines
How far ahead should I book a flight from Seattle to Washington, D.C. Dulles Intl Airport?
Booking 85 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Washington, D.C. Dulles Intl Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?
Currently, February is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of $309). Flying from Seattle to Washington, D.C. Dulles Intl Airport in January is currently the most expensive (average of $643). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from SEA to IAD?
Find hourly flight availability from Seattle to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 29, 2026.
A simple way to save on the total cost of your ticket is to fly from Seattle to Washington, D.C. Dulles Intl Airport in the afternoon. If you’re flexible enough to do this you can expect to save up to 32% on your trip compared to booking a flight at noon.
What is the cheapest day to fly from Seattle to Washington, D.C. Dulles Intl Airport?
Use this chart to determine the cheapest time to fly round-trip from Seattle to Dulles Intl. Price data was last updated on September 26, 2026.
Travelers seeking maximum savings on their Seattle to Washington, D.C. Dulles Intl Airport flight should consider departing on Wednesday afternoons when fares are most often at their lowest. Monday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
The best insider tips for Seattle to Washington, D.C. Dulles Intl Airport flights
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Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to Washington, D.C. Dulles Intl Airport trip
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Reviews of airlines servicing Dulles Intl
Get insights into the airlines that provide service to Dulles Intl. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Dulles Intl. Reviews last updated September 29, 2026.
See what other customers who have flown with Alaska Airlines,Delta, andUnited Airlines from Seattle to Washington, D.C. Dulles Intl Airport have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Boarding
8.1
Crew
8.5
Entertainment
7.0
Comfort
7.8
Overall
7.9
Food
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Crew
8.5
Entertainment
7.0
Comfort
7.8
Overall
7.9
Food
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Crew
8.5
Entertainment
7.0
Comfort
7.8
Overall
7.9
Food
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Crew
8.5
Entertainment
7.0
Comfort
7.8
Overall
7.9
Food
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Crew
8.5
Entertainment
7.0
Comfort
7.8
Overall
7.9
Food
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Boarding
8.1
Crew
8.5
Entertainment
7.0
Comfort
7.8
Overall
7.9
Food
7.0
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Related info for your journey
Find useful and relevant information for your journey from Seattle to Dulles Intl. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near Washington, D.C. Dulles Intl Airport?
Book flights to Washington, D.C. Dulles Intl Airport if you plan to visit one of these locationsAlexandria
Arlington
Owings Mills
Lanham
Chantilly
Woodbridge
Tysons
Reston
Herndon
Hyattsville
Rockville
Fredericksburg
Falls Church
Sterling
Hanover
Laurel
Springfield
Oxon Hill
Clinton
Hunt Valley
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Top 5 airlines flying from Seattle to Dulles Intl
Discover the top 5 airlines that operate flights from Seattle to Dulles Intl. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated September 29, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$144 | Average$316 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$196 | Average$527 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$235 | Average$453 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$237 | Average$463 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$278 | Average$363 | FlexibilityNo cancel fee | On-time62% |