Cheap flights from Seattle to Washington, D.C. from $121

In general, October is the cheapest month to fly from Seattle to Washington, D.C. Dulles Intl Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $325. If you aren’t able to travel to Washington, D.C. Dulles Intl Airport during the month of October, then flying in February is also cheap. Prices for this month can be found on momondo for an average of $344.

Our data shows that Thursday is the least expensive day to fly to Washington, D.C. Dulles Intl Airport. Tickets to fly out on this day can be as low as $427. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to Washington, D.C. Dulles Intl Airport for around $582.

Flying to Washington, D.C. Dulles Intl Airport from Seattle in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $326 when looking at flights departing in the afternoon. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $527 on average. Flights to Washington, D.C. Dulles Intl Airport from Seattle in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.

Fly from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl for the best Seattle/Tacoma Intl - Washington, D.C. Dulles Intl flight prices

You are more likely to see cheaper flights to Washington, D.C. Dulles Intl Airport from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. Dulles Intl Airport for around $419 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. Dulles Intl Airport from Seattle for as low as $317 on momondo.

There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to Washington, D.C. Dulles Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 13% on your flight if you consider stops on a Seattle to Washington, D.C. Dulles Intl Airport flight.

As of February 2026, prices for Seattle to Washington, D.C. Dulles Intl Airport flights are approximately 1% more expensive when compared to flights at the same time last year.

Delta and United Airlines are the most popular carriers operating from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl

Alaska Airlines, United Airlines and Delta are the top three most popular airlines that fly to Washington, D.C. Dulles Intl Airport from Seattle according to our data. Alaska Airlines is the first choice among our users, with 47% of people opting to fly with this airline when traveling to Washington, D.C. Dulles Intl Airport. Keep in mind that there are 6 different airlines that fly to Washington, D.C. Dulles Intl Airport on a routine basis, so you have a few additional options to choose from.

15 flights are operational daily from Seattle to Washington, D.C. Dulles Intl Airport as of February 2026. The most popular departure time for this route is 9:00AM, with 54% of flights per day taking off at noon.

108 flights are operational weekly from Seattle to Washington, D.C. Dulles Intl Airport as of February 2026. The most popular departure day for this route is Mon, with 19% of flights per week taking off on this day.