Cheap flights from Pittsburgh to St. Louis from $99

In general, November is the cheapest month to fly from Pittsburgh to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $283. The month of March is another great option to travel to St. Louis, with average flight prices from Pittsburgh averaging around $324.

The cheapest day to depart on your flight to St. Louis is on a Thursday when prices can be found for as low as $393. 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 Friday because tickets tend to average around $462. 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 Pittsburgh at noon is the least expensive time of day to depart. momondo users have found prices as low as $315 when looking at flights departing at noon. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $445 per ticket.

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

You are more likely to see cheaper flights to St. Louis from Pittsburgh when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $363 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Pittsburgh for as low as $237 on momondo.

No. A direct flight is the cheapest option for a flight between Pittsburgh to St. Louis.

As of May 2026, prices for Pittsburgh to St. Louis flights are approximately 46% more expensive when compared to flights at the same time last year.

American Airlines, Southwest, and Delta are the most popular carriers operating from Pittsburgh to Lambert-St Louis

Southwest, American Airlines and United Airlines are the top three most popular airlines that fly to St. Louis from Pittsburgh according to our data. Southwest is the first choice among our users, with 62% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 4 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

Detroit (DTW) was the most common stop: 67% of momondo users choosing 1-stop flights on this route connected there.

Flights via Chicago (ORD) offer the lowest average round-trip price of $256.

Flights connecting via Detroit (DTW) have the shortest average one-way travel time: 4h 13m.

Detroit (DTW) has the shortest average layover time for this route: 1h 04m.

The number of flights available between Pittsburgh and St. Louis is 1 per day as of May 2026. The most frequent departure time is 6:00AM, with 57% of daily flights leaving at noon.

As of May 2026, there are 9 flights per week flying from Pittsburgh to St. Louis. The most common day of the week flights depart is Mon, with 22% of flights taking off on this day.