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Cheap flights from St. Louis to Philadelphia from $85

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Philadelphia departing on 4/29. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from St. Louis to Philadelphia

Cheap round-trip flights

KAYAK's recommended round-trip deals from the most popular airlines that fly from St. Louis to Philadelphia.
5:45 pm - 7:36 amSTL-PHL
12h 51m1 stop
3:52 pm - 12:06 amPHL-STL
9h 14m1 stop
$198Frontier
Find Deal
Thu, May 15 - Sat, May 17
4:07 pm - 5:37 pmSTL-PHL
24h 30m1 stop
4:33 pm - 12:06 amPHL-STL
8h 33m1 stop
$200Frontier
Find Deal
Thu, May 1 - Sun, May 4
10:10 am - 10:43 pmSTL-PHL
11h 33m1 stop
4:33 pm - 12:06 amPHL-STL
8h 33m1 stop
Thu, May 8 - Mon, May 12
10:10 am - 10:43 pmSTL-PHL
11h 33m1 stop
4:00 pm - 6:41 pmPHL-STL
27h 41m2 stops
Thu, May 8 - Mon, May 12
6:00 am - 9:11 amSTL-PHL
2h 11mnonstop
10:53 am - 12:27 pmPHL-STL
2h 34mnonstop
$339American Airlines
Find Deal
Thu, May 8 - Mon, May 12
6:00 am - 9:11 amSTL-PHL
2h 11mnonstop
10:53 am - 12:27 pmPHL-STL
2h 34mnonstop
$343American Airlines
Find Deal
Fri, May 30 - Mon, Jun 2
10:50 am - 5:00 pmSTL-PHL
5h 10m1 stop
12:20 pm - 10:10 pmPHL-STL
10h 50m2 stops
$364Southwest
Find Deal
Mon, May 12 - Wed, May 14
6:00 am - 11:10 amSTL-PHL
4h 10m1 stop
5:45 pm - 7:10 pmPHL-STL
2h 25mnonstop
$368Southwest
Find Deal
Sat, Apr 26 - Mon, Apr 28
6:45 am - 12:00 pmSTL-PHL
4h 15m1 stop
7:19 pm - 11:38 pmPHL-STL
5h 19m1 stop
$519Delta
Find Deal
Sun, Jun 1 - Sun, Jun 1
6:45 am - 12:00 pmSTL-PHL
4h 15m1 stop
7:19 pm - 11:38 pmPHL-STL
5h 19m1 stop
$628Delta
Find Deal
Fri, May 30 - Fri, May 30

Frontier flights from St. Louis to Philadelphia

Our best Frontier deals on St. Louis to Philadelphia flight tickets
Frontier
May 15
STL5:45 pmLambert-St Louis
12h 51m
1 stop
PHL7:36 amPhiladelphia
May 17
PHL3:52 pmPhiladelphia
9h 14m
1 stop
STL12:06 amLambert-St Louis
Frontier
May 1
STL4:07 pmLambert-St Louis
24h 30m
1 stop
PHL5:37 pmPhiladelphia
May 4
PHL4:33 pmPhiladelphia
8h 33m
1 stop
STL12:06 amLambert-St Louis
Frontier
Apr 15
STL4:57 pmLambert-St Louis
26h 03m
1 stop
PHL8:00 pmPhiladelphia
Apr 17
PHL4:16 pmPhiladelphia
8h 30m
1 stop
STL11:46 pmLambert-St Louis

Spirit Airlines flights from St. Louis to Philadelphia

Our best Spirit Airlines deals on St. Louis to Philadelphia flight tickets
Spirit Airlines
Sep 14
STL8:44 amLambert-St Louis
7h 26m
1 stop
PHL5:10 pmPhiladelphia
Sep 18
PHL6:10 amPhiladelphia
13h 22m
1 stop
STL6:32 pmLambert-St Louis
Spirit Airlines
Apr 20
STL6:10 pmLambert-St Louis
28h 59m
2 stops
PHL12:09 amPhiladelphia
Apr 30
PHL7:05 pmPhiladelphia
23h 10m
1 stop
STL5:15 pmLambert-St Louis
Spirit Airlines
Apr 20
STL6:10 pmLambert-St Louis
28h 59m
2 stops
PHL12:09 amPhiladelphia
Apr 30
PHL9:00 amPhiladelphia
33h 15m
2 stops
STL5:15 pmLambert-St Louis

See travel insights to Philadelphia from

How to get the cheapest flight ticket from St. Louis to Philadelphia

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Philadelphia?

The cheapest month to fly to Philadelphia from St. Louis is in June. Flight prices, which tend to average around $176, are often lower during this time because this is during the off-season. The month of July is another great option to travel to Philadelphia, with average flight prices from St. Louis averaging around $201.

What is the cheapest day to depart on your flight to Philadelphia?

The cheapest day to depart from St. Louis to Philadelphia is on a Friday. Travelers who choose to depart for Philadelphia on a Friday will often find tickets for as low as $563. On the other hand, Sunday is the most expensive day to depart from St. Louis because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $829.

What is the cheapest time of day to depart on your flight to Philadelphia?

According to our data, the cheapest time of day to fly to Philadelphia is in the evening. momondo users have found flights departing from St. Louis to Philadelphia in the evening for as low as $227. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. In contrast, the most expensive time of day to depart to Philadelphia is at noon when prices are around $1,094.

What is the cheapest Lambert-St Louis to Philadelphia flight route?

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

How far in advance should I book a flight to Philadelphia?

You are more likely to see cheaper flights to Philadelphia from St. Louis when booking 22 weeks ahead of your departure date. In general, you can expect to find flights to Philadelphia for around $323 when searching 22 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Philadelphia from St. Louis for as low as $180 on momondo.

What cabin class options are available on Lambert-St Louis to Philadelphia flights?

There are 4 cabin classes available to choose from on Lambert-St Louis to Philadelphia flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have St. Louis to Philadelphia flight prices changed over time?

As of March 2025, prices for St. Louis to Philadelphia flights are approximately 42% more expensive when compared to flights at the same time last year.

When to book flights from St. Louis to Philadelphia

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Philadelphia according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to Philadelphia (STL to PHL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Philadelphia

Best Price Found

$85

Fastest flight time

2h 10m

Direct flights

Every day

Airports in Philadelphia

1 airport
The best one-way flight to Philadelphia from St. Louis in the past 72 hours is $85. The best round-trip flight deal from St. Louis to Philadelphia found on momondo in the last 72 hours is $198.
The fastest flight from St. Louis to Philadelphia takes 2h 10m
Direct flights go from St. Louis to Philadelphia every day.
There is 1 airport near Philadelphia: Philadelphia (PHL)

  • How far is Lambert-St Louis to Philadelphia by plane?

    The distance between Lambert-St Louis and Philadelphia is about 808.1 mi. Flights usually cover this in 2h 10m, depending on flying conditions and air traffic around both airports.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Philadelphia Airport?

    Prices for flights from Lambert-St Louis Airport to Philadelphia Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Philadelphia Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to Philadelphia Airport?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Lambert-St Louis Airport to Philadelphia Airport.

  • What documentation or ID do you need to fly to Philadelphia Airport?

    The travel and health documents you'll need for your trip to Philadelphia Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Philadelphia Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from St. Louis to Philadelphia?

  • What is the most popular airline from St. Louis to Philadelphia?


Best airlines flying from St. Louis to Philadelphia

Compare and see reviews for airlines that fly from St. Louis to Philadelphia with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $48Free CancellationRating
6.0
3,276 reviews
Search Frontier flights
American AirlinesPriceFrom $131Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
DeltaPriceFrom $196Free CancellationRating
8.0
7,899 reviews
Search Delta flights
SouthwestPriceFrom $284Free CancellationRating
8.0
4,276 reviews
Search Southwest flights
  • Southwest Flights From St. Louis to Philadelphia

    Southwest flight deals from St. Louis to Philadelphia start from $284 round-trip. Over the 8 Southwest flights for this route in a normal week, average airfare is usually $409 round-trip - but some users have found much cheaper deals with momondo.

  • American Airlines Flights From St. Louis to Philadelphia

    American Airlines (7.2/10 from 10,000 reviews) operates around 9 flights from St. Louis to Philadelphia in any given week. The average American Airlines airfare for this route is around $297, with deals from around $131 rare but found on momondo. Referenced prices are for round-trip St. Louis to Philadelphia flight searches in the last 72 hours.


Traveling to a place near Philadelphia?

Book flights to Philadelphia if you plan to visit one of these locations
Wildwood
Rehoboth Beach
Cape May
Ocean City
Wildwood Crest
Reading
King of Prussia
Newark
Dover
North Wildwood
Cherry Hill
Dewey Beach
Lewes
Exton
Vineland
Essington
Pottstown
New Castle
Avalon
West Chester

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Philadelphia?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from St. Louis to Philadelphia. momondo saves you time and could save you money on your trip.

Can I find flights from St. Louis to Philadelphia with flexible booking policies on momondo?

momondo does allow users to show only those flights to Philadelphia from St. Louis which offer a flexible booking policy as well as other useful filters and features.

How can momondo help me find flights from St. Louis to Philadelphia?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to Philadelphia.

I’m not ready to book a flight from St. Louis to Philadelphia right now. Can momondo alert me if prices change?

If you are not ready to book a flight from St. Louis to Philadelphia now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Philadelphia and let you know when they change.


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