Cheap flights from Phoenix Sky Harbor Intl Airport to St. Louis from $82

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 December is another great option to travel to St. Louis, with average flight prices from Phoenix Sky Harbor Intl Airport averaging around $333.

The cheapest day to depart on your flight to St. Louis is on a Friday when prices can be found for as low as $349. 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 $442. 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 in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $365 when looking at flights departing in the afternoon. In the evening is when there is more demand to fly to St. Louis, so prices are often more expensive at around $396 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 $362 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 $282 on momondo.

There are 3 cabin classes available to choose from on Phoenix Sky Harbor Intl to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 21% on your flight if you consider stops on a Phoenix Sky Harbor Intl Airport to St. Louis flight.

As of March 2026, prices for Phoenix Sky Harbor Intl Airport to St. Louis flights are approximately 37% cheaper when compared to flights at the same time last year.

Frontier, Alaska Airlines, 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 42% 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 March 2026, there are 9 flights per day flying from Phoenix Sky Harbor Intl Airport to St. Louis. The most common time of day flights depart is 7:00PM, with 38% of flights taking off at noon.

As of March 2026, there are 63 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 19% of flights taking off on this day.