Cheap flights from District of Columbia to St. Louis from $68

In general, August is the cheapest month to fly from District of Columbia to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $273. The month of October is another great option to travel to St. Louis, with average flight prices from District of Columbia averaging around $293.

The cheapest day to depart on your flight to St. Louis is on a Saturday when prices can be found for as low as $326. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $402. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

Flying to St. Louis from District of Columbia in the evening is the least expensive time of day to depart. momondo users have found prices as low as $308 when looking at flights departing in the evening. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $381 per ticket.

Fly from Washington, D.C. Reagan-National to Lambert-St Louis for the best District of Columbia - Lambert-St Louis flight prices

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

Southwest, American Airlines and Frontier are the top three most popular airlines that fly to St. Louis from District of Columbia according to our data. Southwest is the first choice among our users, with 49% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 5 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

As of February 2026, there are 12 flights per day flying from District of Columbia to St. Louis. The most common time of day flights depart is 6:00PM, with 46% of flights taking off in the evening.

As of February 2026, 86 flights take off from District of Columbia and land in St. Louis each week. The most common flight departure day for this route is Mon, with 17% of weekly flights taking off on this day.