Cheap flights from Seattle to Washington, D.C. from $129

The month of January is, on average, the cheapest month to fly to Washington, D.C. from Seattle, with most prices found around $363. If you’re not able to fly to Washington, D.C. in January, then February is your next best option. Flight prices from Seattle to Washington, D.C. during February average around $369.

On average, the least expensive day to fly to Washington, D.C. from Seattle is on a Friday. momondo users have found tickets for Friday departures for as low as $453. However, this price may fluctuate depending on the airline, the season, and holidays. When flying out on a Monday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to Washington, D.C. for around $638.

In the afternoon is the cheapest time of day to fly from Seattle to Washington, D.C. when you can find flight prices for as low as $385. Flying to Washington, D.C. in the afternoon is an ideal time because this is during off-peak travel hours. Try not to purchase tickets in the morning because they tend to be around $517. Of course, these prices can vary depending on the time of year and what airport you fly to.

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

You are more likely to see cheaper flights to Washington, D.C. from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. for around $453 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. from Seattle for as low as $373 on momondo.

There are 4 cabin classes available to choose from on Seattle to Washington, D.C. 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. flight.

As of October 2026, prices for Seattle to Washington, D.C. flights are approximately 16% more expensive when compared to flights at the same time last year.

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

Alaska Airlines, Delta and United Airlines are the top three most popular airlines that fly to Washington, D.C. from Seattle according to our data. Alaska Airlines is the first choice among our users, with 58% of people opting to fly with this airline when traveling to Washington, D.C.. Keep in mind that there are 6 different airlines that fly to Washington, D.C. on a routine basis, so you have a few additional options to choose from.

Las Vegas (LAS) was the most common stop: 43% of momondo users choosing 1-stop flights on this route connected there.

Flights via Detroit (DTW) offer the lowest average round-trip price of $236.

Flights connecting via Detroit (DTW) have the shortest average one-way travel time: 6h 32m.

Detroit (DTW) has the shortest average layover time for this route: 0h 41m.

18 flights are operational daily from Seattle to Washington, D.C. as of October 2026. The most popular departure time for this route is 8:00AM, with 48% of flights per day taking off at noon.

As of October 2026, 126 flights take off from Seattle and land in Washington, D.C. each week. The most common flight departure day for this route is Sat, with 20% of weekly flights taking off on this day.