What is the cheapest airline that flies from Lambert-St Louis to Philadelphia?

Frontier and Delta are the most popular carriers operating from Lambert-St Louis to Philadelphia

How many flights depart from St. Louis to Philadelphia on average per day?

As of May 2026, 6 flights take off from St. Louis and land in Philadelphia each day. The most common flight departure time for this route is 1:00PM, with 46% of daily flights taking off in the afternoon.

What airlines fly to Philadelphia?

American Airlines, Delta and United Airlines are the top three most popular airlines that fly to Philadelphia from St. Louis according to our data. American Airlines is the first choice among our users, with 39% of people opting to fly with this airline when traveling to Philadelphia. Keep in mind that there are 6 different airlines that fly to Philadelphia on a routine basis, so you have a few additional options to choose from.

How many flights depart from St. Louis to Philadelphia on average per week?

The number of flights available between St. Louis and Philadelphia is 42 per week as of May 2026. The most frequent departure day is Mon, with 19% of weekly flights leaving on this day.

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?

The number of operators available for flights from Lambert-St Louis Airport to Philadelphia Airport is 5 as of May 2026.

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.

$90 Cheap Flights from St. Louis to Philadelphia in 2026

Q: What is the typical price of a round-trip flight between St. Louis and Philadelphia?

Prices are currently low for flights on this route. Typical prices usually range from $479 to $320. The lowest price recently found on this route was $175.

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Find the cheapest flights from St. Louis to Philadelphia

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

6:30 pm - 6:21 am

STL

PHL

10h 51m

1 stop

6:10 am - 2:48 pm

PHL

STL

9h 38m

1 stop

$175Frontier

Sat, May 23 - Tue, May 26

6:33 pm - 7:12 am

STL

PHL

11h 39m

1 stop

5:21 am - 11:57 pm

PHL

STL

19h 36m

1 stop

$180Frontier

Thu, May 28 - Sun, May 31

6:30 pm - 6:21 am

STL

PHL

10h 51m

1 stop

10:40 am - 8:11 pm

PHL

STL

10h 31m

1 stop

$181Frontier

Sat, May 23 - Fri, May 29

4:19 pm - 11:29 pm

STL

PHL

6h 10m

1 stop

5:10 pm - 11:49 pm

PHL

STL

7h 39m

1 stop

$185Frontier

Wed, Jun 3 - Wed, Jun 10

6:33 pm - 7:15 am

STL

PHL

11h 42m

1 stop

8:30 am - 5:30 pm

PHL

STL

10h 00m

1 stop

$190Frontier

Tue, Aug 4 - Tue, Aug 25

4:19 pm - 8:54 am

STL

PHL

15h 35m

1 stop

10:11 am - 11:57 pm

PHL

STL

14h 46m

1 stop

$204Frontier

Wed, May 27 - Mon, Jun 1

4:19 pm - 11:29 pm

STL

PHL

6h 10m

1 stop

5:21 am - 10:29 am

PHL

STL

6h 08m

1 stop

$205Frontier

Fri, May 29 - Mon, Jun 1

8:08 pm - 5:39 am

STL

PHL

8h 31m

1 stop

5:59 pm - 11:59 pm

PHL

STL

7h 00m

1 stop

$210Frontier

Fri, Jul 24 - Tue, Jul 28

4:17 pm - 12:44 am

STL

PHL

7h 27m

1 stop

5:10 pm - 11:49 pm

PHL

STL

7h 39m

1 stop

$212Frontier

Tue, Jun 16 - Wed, Jun 17

6:33 pm - 7:12 am

STL

PHL

11h 39m

1 stop

8:35 pm - 7:23 pm

PHL

STL

23h 48m

1 stop

$213Frontier

Thu, May 28 - Wed, Jun 3

Southwest flights from St. Louis to Philadelphia

Our best Southwest deals on St. Louis to Philadelphia flight tickets

Southwest

Jun 3

STL6:50 pmLambert-St Louis

2h 10m

PHL10:00 pmPhiladelphia

Jun 10

PHL6:20 amPhiladelphia

2h 20m

STL7:40 amLambert-St Louis

$277

Southwest

May 30

STL6:55 pmLambert-St Louis

2h 10m

PHL10:05 pmPhiladelphia

Jun 2

PHL6:35 pmPhiladelphia

2h 25m

STL8:00 pmLambert-St Louis

$284

Southwest

Jun 3

STL6:50 pmLambert-St Louis

2h 10m

PHL10:00 pmPhiladelphia

Jun 10

PHL7:25 amPhiladelphia

6h 10m

1 stop

STL12:35 pmLambert-St Louis

$287

Frontier flights from St. Louis to Philadelphia

Our best Frontier deals on St. Louis to Philadelphia flight tickets

Frontier

May 23

STL6:30 pmLambert-St Louis

10h 51m

1 stop

PHL6:21 amPhiladelphia

May 26

PHL6:10 amPhiladelphia

9h 38m

1 stop

STL2:48 pmLambert-St Louis

$175

Frontier

May 28

STL6:33 pmLambert-St Louis

11h 39m

1 stop

PHL7:12 amPhiladelphia

Jun 1

PHL5:21 amPhiladelphia

19h 36m

1 stop

STL11:57 pmLambert-St Louis

$180

Frontier

May 23

STL6:30 pmLambert-St Louis

10h 51m

1 stop

PHL6:21 amPhiladelphia

May 29

PHL10:40 amPhiladelphia

10h 31m

1 stop

STL8:11 pmLambert-St Louis

$181

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Sat 5/23

6:30 pm-6:21 am

1 stop10h 51m

Philadelphia

Tue 5/26

6:10 am-2:48 pm

1 stop9h 38m

$175

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Thu 5/28

6:33 pm-7:12 am

1 stop11h 39m

Philadelphia

Sun 5/31

5:21 am-11:57 pm

1 stop19h 36m

$180

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Sat 5/23

6:30 pm-6:21 am

1 stop10h 51m

Philadelphia

Fri 5/29

10:40 am-8:11 pm

1 stop10h 31m

$181

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Wed 6/3

4:19 pm-11:29 pm

1 stop6h 10m

Philadelphia

Wed 6/10

5:10 pm-11:49 pm

1 stop7h 39m

$185

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Tue 8/4

6:33 pm-7:15 am

1 stop11h 42m

Philadelphia

Tue 8/25

8:30 am-5:30 pm

1 stop10h 00m

$190

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Wed 5/27

4:19 pm-8:54 am

1 stop15h 35m

Philadelphia

Mon 6/1

10:11 am-11:57 pm

1 stop14h 46m

$204

Quickest round-trip

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Fri 5/29

4:19 pm-11:29 pm

1 stop6h 10m

Philadelphia

Mon 6/1

5:21 am-10:29 am

1 stop6h 08m

$205

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Fri 7/24

8:08 pm-5:39 am

1 stop8h 31m

Philadelphia

Tue 7/28

5:59 pm-11:59 pm

1 stop7h 00m

$210

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Tue 6/16

4:17 pm-12:44 am

1 stop7h 27m

Philadelphia

Wed 6/17

5:10 pm-11:49 pm

1 stop7h 39m

$212

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Thu 5/28

6:33 pm-7:12 am

1 stop11h 39m

Philadelphia

Wed 6/3

8:35 pm-7:23 pm

1 stop23h 48m

$213

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

Prices

Airlines

Other information

What is the typical price of a round-trip flight between St. Louis and Philadelphia?

What is the cheapest month to fly to Philadelphia?

The cheapest month to fly to Philadelphia from St. Louis is in August. Flight prices, which tend to average around $285, are often lower during this time because this is during the off-season. The month of September is another great option to travel to Philadelphia, with average flight prices from St. Louis averaging around $343.

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 $558. On the other hand, Saturday 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 $966.

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 $423. 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 $1,055.

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 from St. Louis to Philadelphia?

You are more likely to see cheaper flights to Philadelphia from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Philadelphia for around $411 when searching 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 $327 on momondo.

Can stopping save me money on St. Louis to Philadelphia flights?

You could potentially save up to 21% on your flight if you consider stops on a St. Louis to Philadelphia flight.

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

As of May 2026, prices for St. Louis to Philadelphia flights are approximately 245% 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	$217
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 $217. The best round-trip flight deal from St. Louis to Philadelphia found on momondo in the last 72 hours is $401.

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 in Philadelphia. From St. Louis there are direct flights to Philadelphia (PHL).

Search flight deals

Frequently asked questions about flying from St. Louis to Philadelphia

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?
The number of operators available for flights from Lambert-St Louis Airport to Philadelphia Airport is 5 as of May 2026.
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?
Based on momondo bookings for flights between St. Louis and Philadelphia, the leading plane model is Airbus A319, making up 31.08% of the total bookings. Other popular models include Boeing 737 MAX 8 with 22.97%, Canadair (Bombardier) Regional Jet 900 with 12.61%, and Boeing 737-800 Passenger/BBJ2 (winglets) with 12.39%.
What is the most popular airline from St. Louis to Philadelphia?
momondo data reveals that the most frequently booked airline on the route from St. Louis to Philadelphia is American Airlines, representing 56% of all bookings. The subsequent popular airlines are Southwest at 29%, Frontier at 11%, and Spirit Airlines at 2%.

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
Spirit Airlines	PriceFrom $82	Free Cancellation	Rating 6.3 8,638 reviews	Search Spirit Airlines flights
Frontier	PriceFrom $142	Free Cancellation	Rating 5.6 2,962 reviews	Search Frontier flights
Delta	PriceFrom $231	Free Cancellation	Rating 7.9 8,456 reviews	Search Delta flights
American Airlines	PriceFrom $245	Free Cancellation	Rating 7.1 11,667 reviews	Search American Airlines flights
Southwest	PriceFrom $252	Free Cancellation	Rating 7.9 4,302 reviews	Search Southwest flights

Southwest Flights From St. Louis to Philadelphia
Southwest flight deals from St. Louis to Philadelphia start from $252 round-trip. Over the 13 Southwest flights for this route in a normal week, average airfare is usually $446 round-trip - but some users have found much cheaper deals with momondo.
American Airlines Flights From St. Louis to Philadelphia
American Airlines (7.1/10 from 11,667 reviews) operates around 12 flights from St. Louis to Philadelphia in any given week. The average American Airlines airfare for this route is around $428, with deals from around $245 rare but found on momondo. Referenced prices are for round-trip St. Louis to Philadelphia flight searches in the last 72 hours.

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Rehoboth Beach

Cape May

Wildwood Crest

Ocean City

Cherry Hill

King of Prussia

Newark

Dewey Beach

Reading

Avalon

Dover

North Wildwood

Lewes

Stone Harbor

New Castle

Essington

Vineland

Pottstown

Somers Point

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.