Cheap flights from Phoenix Sky Harbor Intl Airport to St. Louis from $80

In general, January is the cheapest month to fly from Phoenix Sky Harbor Intl 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 Phoenix Sky Harbor Intl Airport averaging around $313.

The cheapest day to depart on your flight to St. Louis is on a Friday when prices can be found for as low as $353. 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 $451. 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 Phoenix Sky Harbor Intl Airport at noon is the least expensive time of day to depart. momondo users have found prices as low as $341 when looking at flights departing at noon. In the evening is when there is more demand to fly to St. Louis, so prices are often more expensive at around $397 per ticket.

Fly from Phoenix Sky Harbor Intl to Lambert-St Louis for the best Phoenix Sky Harbor Intl - Lambert-St Louis flight prices

You are more likely to see cheaper flights to St. Louis from Phoenix Sky Harbor Intl Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $366 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Phoenix Sky Harbor Intl Airport for as low as $305 on momondo.

No. A direct flight is the cheapest option for a flight between Phoenix Sky Harbor Intl Airport to St. Louis.

As of May 2026, prices for Phoenix Sky Harbor Intl Airport to St. Louis flights are approximately 178% more expensive when compared to flights at the same time last year.

Frontier and Southwest are the most popular carriers operating from Phoenix Sky Harbor Intl to Lambert-St Louis

Southwest, American Airlines and Frontier are the top three most popular airlines that fly to St. Louis from Phoenix Sky Harbor Intl Airport according to our data. Southwest is the first choice among our users, with 43% 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.

As of May 2026, there are 6 flights per day flying from Phoenix Sky Harbor Intl Airport to St. Louis. The most common time of day flights depart is 8:00AM, with 48% of flights taking off at noon.

As of May 2026, there are 44 flights per week flying from Phoenix Sky Harbor Intl Airport to St. Louis. The most common day of the week flights depart is Mon, with 20% of flights taking off on this day.