Cheap flights from Washington, D.C. Reagan-National Airport to St. Louis from $119

In general, January is the cheapest month to fly from Washington, D.C. Reagan-National Airport to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $309. The month of October is another great option to travel to St. Louis, with average flight prices from Washington, D.C. Reagan-National Airport averaging around $359.

The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $362. 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 $471. 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 Washington, D.C. Reagan-National Airport at noon is the least expensive time of day to depart. momondo users have found prices as low as $375 when looking at flights departing at noon. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $427 per ticket.

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

You are more likely to see cheaper flights to St. Louis from Washington, D.C. Reagan-National Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $396 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Washington, D.C. Reagan-National Airport for as low as $201 on momondo.

There are 3 cabin classes available to choose from on Washington, D.C. Reagan-National Airport to St. Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

No. A direct flight is the cheapest option for a flight between Washington, D.C. Reagan-National Airport to St. Louis.

As of September 2026, prices for Washington, D.C. Reagan-National Airport to St. Louis flights are approximately 48% more expensive when compared to flights at the same time last year.

4 flights are operational daily from Washington, D.C. Reagan-National Airport to St. Louis as of September 2026. The most popular departure time for this route is 8:00AM, with 44% of flights per day taking off in the afternoon.

31 flights are operational weekly from Washington, D.C. Reagan-National Airport to St. Louis as of September 2026. The most popular departure day for this route is Mon, with 23% of flights per week taking off on this day.