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Cheap Flights from Philadelphia to St Louis

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Compare Philadelphia International to St Louis flight deals

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Flight deals from Philadelphia International to St Louis

Looking for a cheap last-minute deal or the best return flight from Philadelphia International to St Louis? Find the lowest prices on one-way and return tickets right here.
St Louis.$254 per passenger.Departing Wed, 2 Apr, returning Thu, 3 Apr.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Philadelphia International on Wed, 2 Apr, arriving in St Louis.Inbound indirect flight with Frontier Airlines, departs from St Louis on Thu, 3 Apr, arriving in Philadelphia International.Price includes taxes and charges.From $254, select.
St Louis.$255 per passenger.Departing Tue, 20 May, returning Tue, 20 May.Return flight with Spirit Airlines.Outbound indirect flight with Spirit Airlines, departs from Philadelphia International on Tue, 20 May, arriving in St Louis.Inbound indirect flight with Spirit Airlines, departs from St Louis on Tue, 20 May, arriving in Philadelphia International.Price includes taxes and charges.From $255, select.
St Louis.$285 per passenger.Departing Mon, 31 Mar, returning Fri, 16 May.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Philadelphia International on Mon, 31 Mar, arriving in St Louis.Inbound indirect flight with Frontier Airlines, departs from St Louis on Fri, 16 May, arriving in Philadelphia International.Price includes taxes and charges.From $285, select.
St Louis.$298 per passenger.Departing Tue, 25 Mar, returning Tue, 1 Apr.Return flight with Spirit Airlines.Outbound indirect flight with Spirit Airlines, departs from Philadelphia International on Tue, 25 Mar, arriving in St Louis.Inbound indirect flight with Spirit Airlines, departs from St Louis on Tue, 1 Apr, arriving in Philadelphia International.Price includes taxes and charges.From $298, select.
St Louis.$312 per passenger.Departing Thu, 20 Mar, returning Wed, 26 Mar.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Philadelphia International on Thu, 20 Mar, arriving in St Louis.Inbound indirect flight with Frontier Airlines, departs from St Louis on Wed, 26 Mar, arriving in Philadelphia International.Price includes taxes and charges.From $312, select.
St Louis.$317 per passenger.Departing Thu, 29 May, returning Mon, 2 Jun.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Philadelphia International on Thu, 29 May, arriving in St Louis.Inbound indirect flight with Frontier Airlines, departs from St Louis on Mon, 2 Jun, arriving in Philadelphia International.Price includes taxes and charges.From $317, select.
St Louis.$333 per passenger.Departing Thu, 26 Jun, returning Sat, 28 Jun.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Philadelphia International on Thu, 26 Jun, arriving in St Louis.Inbound indirect flight with Frontier Airlines, departs from St Louis on Sat, 28 Jun, arriving in Philadelphia International.Price includes taxes and charges.From $333, select.
St Louis.$365 per passenger.Departing Thu, 17 Apr, returning Fri, 2 May.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Philadelphia International on Thu, 17 Apr, arriving in St Louis.Inbound indirect flight with Frontier Airlines, departs from St Louis on Fri, 2 May, arriving in Philadelphia International.Price includes taxes and charges.From $365, select.

Find the cheapest month to fly from Philadelphia International to St Louis

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Philadelphia International to St Louis flights are currently cheapest in April.
Mar
from $312
Apr
from $254
May
from $255
Jun
from $333
Jul
from $692
Aug
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Sep
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Oct
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Nov
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Dec
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Jan
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Feb
from $2,265

Direct flights from Philadelphia International to St Louis

Philadelphia International to St Louis: Alternative routes

Compare routes from Philadelphia International to St Louis below. You may find an airport to fly into that's cheaper, faster, or easier than St Louis.

Philadelphia to St Louis: Flight information

The things to know before you go.
Cheapest flight found$254
Cheapest month to flyApril
Average flight time2 hrs, 35 mins
Most popular airlineQatar Airways
Average flights per week76

Finding cheap flights from Philadelphia International to St Louis: Frequently asked questions

The best price we found for a return flight from Philadelphia International to St Louis is $254. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
2 hours and 35 minutes is the average flight time from Philadelphia International to St Louis.
Qatar Airways, American Airlines and Southwest Airlines fly direct from Philadelphia International to St Louis.
As of March 2025, there are 76 flights per week flying from Philadelphia International to St Louis.
The cheapest month to fly from Philadelphia International to St Louis is usually March 2025.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Philadelphia International Airport to St Louis Airport on Wednesday, 2 April 2025.
Yes – the average flight time is 2 hours and 35 minutes.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to St Louis but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.
We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to St Louis is around 40 days in advance, so don’t leave your flight to the last minute.
Currently, Frontier Airlines and Southwest Airlines offer the cheapest flight tickets to St Louis.

Travelling from Philadelphia International Airport (PHL) to Lambert-St. Louis International Airport (STL): what you need to know

  • The average time for a direct flight from Philadelphia International Airport to Lambert-St. Louis International Airport is 2 hours 31 minutes. St Louis's timezone is UTC-5, making St Louis 1 hour behind Philadelphia.

  • Every week, there are 35 flights from Philadelphia International Airport to Lambert-St. Louis International Airport. The first flight from PHL to STL is at 06:00 and the latest is at 22:36.

  • If you're going away during a popular month like August, head to the airport even earlier. You'll want to arrive up to four hours before international flights and two hours ahead of domestic departures. Expect lines to be longer during peak periods like spring break and summer.

  • Getting to St Louis (and seeing more of United States!) is straightforward with Frontier Airlines. This popular carrier runs direct flights from Philadelphia International Airport to Lambert-St. Louis International Airport.

  • We make it a breeze to get a flight with a stopover. To see your options for flights from Philadelphia International Airport to Lambert-St. Louis International Airport, uncheck 'Direct flights only.' Then, pick a flight with a stop long enough to tour the city of your choice. Popular stopovers between PHL and STL are:

    • Ronald Reagan National Airport

    • Nashville International Airport

    • Washington Dulles International Airport

  • You won't need your passport or a visa to travel within United States. You will need a valid proof of identity however, like a driver's license or ID card. Add them to your packing list once you've got your cheap ticket from PHL to STL.

How to find the cheapest flights from Philadelphia International Airport (PHL) to Lambert-St. Louis International Airport (STL)

  • The best price we've seen for a one-way ticket from Philadelphia International Airport to Lambert-St. Louis International Airport is $119. The cheapest price for a return flight is $254. Bear in mind that fares could change due to demand at the time of booking.

  • To score cheap flight tickets from PHL to STL, book your trip 9 months ahead of your planned departure.

  • Organise your trip for May. That's the cheapest month for tickets from Philadelphia International Airport to Lambert-St. Louis International Airport. If you have flexibility with your dates, use the 'Whole month' tool to see the lowest price across every month.

  • Sign into your online account or use the app to set up a Price Alert. You'll be notified straight away if there's a better deal on this route. It's simple to do, and it'll save you from checking for cheap flight tickets from PHL to STL every day.

  • Use filters to tailor your flights from Philadelphia International Airport to Lambert-St. Louis International Airport. Simply select your ideal arrival and departure times, number of stops and airlines. Or sort your results by 'Cheapest' to find the best deals.

Handy information about Philadelphia International Airport (PHL)

Arriving at Lambert-St. Louis International Airport (STL)

Getting from Lambert-St. Louis International Airport (STL) to central St Louis

  • From Lambert-St. Louis International Airport, St Louis is approximately 26 kilometres away. It takes around 21 minutes to get to the centre driving.

  • If you're travelling by public transport, expect a journey time of around 36 minutes.

When to fly to Lambert-St. Louis International Airport (STL)

  • The quietest month for a flight from Philadelphia International Airport to Lambert-St. Louis International Airport is April, while July is the busiest. Pick the best time to visit St Louis based on whether you prefer a laid-back vibe or a more bustling atmosphere.

  • The warmest month in St Louis is July, with temperatures ranging between 17ºC and 33ºC. Lock in your flights from Philadelphia International Airport to Lambert-St. Louis International Airport in this month if this is the kind of weather you like.

  • Look for cheap flight tickets from PHL to STL in January if you like cooler conditions. Temperatures are at their lowest around then, ranging between -8ºC and 7ºC on average.

More about St Louis

Complete your St Louis trip with hotels and a car rental

  • After you've secured your cheap ticket to Lambert-St. Louis International Airport, check out the lowest prices and exclusive rates for hotels. You can also compare a range of car rental companies in one place to get the best car rental price for your St Louis trip.

Plan the rest of your trip from Philadelphia to St Louis

Prices shown on this page are estimated lowest prices only. Found in the last 45 days.