Cheap flights from San Antonio to St. Louis from $96

In general, August is the cheapest month to fly from San Antonio to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $236. The month of February is another great option to travel to St. Louis, with average flight prices from San Antonio averaging around $313.

The cheapest day to depart on your flight to St. Louis is on a Wednesday 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. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $535. 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 San Antonio in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $342 when looking at flights departing in the afternoon. At noon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $527 per ticket.

Fly from San Antonio to Lambert-St Louis for the best San Antonio - Lambert-St Louis flight prices

As of May 2026, prices for San Antonio to St. Louis flights are approximately 28% more expensive when compared to flights at the same time last year.

United Airlines, Delta, and Southwest are the most popular carriers operating from San Antonio to Lambert-St Louis

Southwest, American Airlines and United Airlines are the top three most popular airlines that fly to St. Louis from San Antonio according to our data. Southwest is the first choice among our users, with 74% 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.

Atlanta (ATL) was the most common stop: 80% of momondo users choosing 1-stop flights on this route connected there.

Flights via Dallas (DFW) offer the lowest average round-trip price of $231.

Flights connecting via Dallas (DFW) have the shortest average one-way travel time: 3h 53m.

Dallas (DFW) has the shortest average layover time for this route: 0h 52m.

The number of flights available between San Antonio and St. Louis is 1 per day as of May 2026. The most frequent departure time is 7:00AM, with 62% of daily flights leaving at noon.

The number of flights available between San Antonio and St. Louis is 9 per week as of May 2026. The most frequent departure day is Mon, with 22% of weekly flights leaving on this day.