Cheap flights from the United States to St. Louis from $19

In general, October is the cheapest month to fly from United States to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $333. The month of September is another great option to travel to St. Louis, with average flight prices from United States 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 $385. 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 Monday because tickets tend to average around $497. 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 United States in the evening is the least expensive time of day to depart. momondo users have found prices as low as $395 when looking at flights departing in the evening. At noon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $425 per ticket.

Fly from Atlanta Hartsfield-Jackson to Lambert-St Louis for the best United States - Lambert-St Louis flight prices

There are 4 cabin classes available to choose from on United States 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 United States to St. Louis.

Frontier, Southwest, and Delta are the most popular carriers operating from United States to Lambert-St Louis

Southwest, Frontier and American Airlines are the top three most popular airlines that fly to St. Louis from United States according to our data. Southwest is the first choice among our users, with 38% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 13 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

Historically, on average around 19% of flights between United States and St. Louis have experienced a delay on any given week. The average delay length over the past 12 months has been 128 minutes.

Generally, flights departing in the morning tend to experience fewer delays. Flights in the evening have, in the past, seen delays more frequently in comparison.

Tuesday is statistically the day of the week which experiences the fewest number of delays on this flight route. Sunday has historically seen more delays on average compared to the rest of the week.

According to our data, Southwest have had the least number of delays on this route over the last 12 months; with about 17% of their flights experiencing any sort of delay.

72 flights are operational daily from United States to St. Louis as of August 2026. The most popular departure time for this route is 5:00PM, with 45% of flights per day taking off in the afternoon.

506 flights are operational weekly from United States to St. Louis as of August 2026. The most popular departure day for this route is Fri, with 25% of flights per week taking off on this day.