Cheap flights from St. Louis to District of Columbia from $70

In general, August is the cheapest month to fly from St. Louis to District of Columbia. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $229. If you don’t want to visit District of Columbia in August, then you should wait until October to fly from St. Louis, when ticket prices are also cheap, with an average price of $262.

The cheapest day to depart on your flight to District of Columbia is on a Tuesday when prices can be found for as low as $366. This is often the case because there is less demand to fly during this day of the week. On the other hand, Wednesday is the most expensive day to depart from St. Louis because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $475.

Flying to District of Columbia from St. Louis in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $333 when looking at flights departing in the afternoon. Flights to District of Columbia are more costly at noon, with an average ticket price of $789. Departure times at noon fall within the peak daily travel times, which is why tickets can be more expensive.

Fly from Lambert-St Louis to Baltimore/Washington for the best Lambert-St Louis - District of Columbia flight prices

You are more likely to see cheaper flights to District of Columbia from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to District of Columbia for around $379 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to District of Columbia from St. Louis for as low as $236 on momondo.

There are 4 cabin classes available to choose from on Lambert-St Louis to District of Columbia flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Southwest, Delta, and United Airlines are the most popular carriers operating from Lambert-St Louis to District of Columbia

Southwest, American Airlines and United Airlines are the top three most popular airlines that fly to District of Columbia from St. Louis according to our data. Southwest is the first choice among our users, with 52% of people opting to fly with this airline when traveling to District of Columbia. Keep in mind that there are 5 different airlines that fly to District of Columbia on a routine basis, so you have a few additional options to choose from.

10 flights are operational daily from St. Louis to District of Columbia as of April 2026. The most popular departure time for this route is 8:00AM, with 48% of flights per day taking off in the afternoon.

The number of flights available between St. Louis and District of Columbia is 70 per week as of April 2026. The most frequent departure day is Thu, with 20% of weekly flights leaving on this day.