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Cheap flights from St. Louis to Pennsylvania from $56

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 Pennsylvania departing on 2/25. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from St. Louis to Pennsylvania

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
8:22 pm - 11:14 am
STL
-
PHL
13h 52m1 stop
Frontier Logo
8:25 pm - 11:33 pm
PHL
-
STL
28h 08m1 stop
$130Frontier
Mon, Jan 26 - Tue, Jan 27
Multiple Airlines Logo
3:43 pm - 11:30 pm
STL
-
EWR
6h 47m1 stop
Multiple Airlines Logo
5:40 pm - 6:51 am
EWR
-
STL
14h 11m1 stop
$130Multiple Airlines
Thu, Jan 8 - Tue, Jan 13
American Airlines Logo
3:54 pm - 11:29 pm
STL
-
PIT
6h 35m1 stop
American Airlines Logo
4:00 pm - 10:44 pm
PIT
-
STL
7h 44m1 stop
$191American Airlines
Thu, Jan 8 - Sat, Jan 10
Southwest Logo
1:10 pm - 4:10 pm
STL
-
DCA
2h 00mnonstop
Southwest Logo
12:25 pm - 1:45 pm
DCA
-
STL
2h 20mnonstop
$227Southwest
Thu, Dec 25 - Thu, Jan 1
United Airlines Logo
8:15 am - 11:24 am
STL
-
IAD
2h 09mnonstop
United Airlines Logo
5:50 pm - 7:22 pm
IAD
-
STL
2h 32mnonstop
$227United Airlines
Thu, Dec 25 - Wed, Dec 31
Southwest Logo
8:20 am - 11:15 am
STL
-
DCA
1h 55mnonstop
Southwest Logo
12:00 pm - 1:35 pm
DCA
-
STL
2h 35mnonstop
$231Southwest
Tue, Jan 13 - Tue, Jan 20
United Airlines Logo
8:30 am - 11:40 am
STL
-
IAD
2h 10mnonstop
United Airlines Logo
8:40 am - 10:13 am
IAD
-
STL
2h 33mnonstop
$231United Airlines
Tue, Jan 13 - Sat, Jan 17
American Airlines Logo
9:54 am - 12:59 pm
STL
-
DCA
2h 05mnonstop
American Airlines Logo
7:40 am - 9:24 am
DCA
-
STL
2h 44mnonstop
$235American Airlines
Wed, Jan 7 - Sat, Jan 10
Delta Logo
5:32 pm - 9:00 pm
STL
-
LGA
2h 28mnonstop
Delta Logo
10:30 am - 12:33 pm
LGA
-
STL
3h 03mnonstop
$267Delta
Tue, Jan 20 - Thu, Jan 29
Delta Logo
6:00 am - 11:45 am
STL
-
LGA
4h 45m1 stop
Delta Logo
2:55 pm - 4:52 pm
LGA
-
STL
2h 57mnonstop
$277Delta
Thu, Feb 12 - Tue, Feb 17

Delta flights from St. Louis to Pennsylvania

Our best Delta deals on St. Louis to Pennsylvania flight tickets
Delta
Jan 13
STL12:00 pmLambert-St Louis
4h 17m
1 stop
IAD5:17 pmWashington, D.C. Dulles Intl
Jan 20
IAD5:26 pmWashington, D.C. Dulles Intl
4h 17m
1 stop
STL8:43 pmLambert-St Louis
$251
Find similar
Delta
Jan 20
STL1:18 pmLambert-St Louis
2h 25m
LGA4:43 pmNew York LaGuardia
Feb 1
LGA6:05 pmNew York LaGuardia
3h 01m
STL8:06 pmLambert-St Louis
$267
Find similar
Delta
Dec 24
STL7:10 amLambert-St Louis
2h 27m
LGA10:37 amNew York LaGuardia
Jan 6
LGA10:30 amNew York LaGuardia
3h 03m
STL12:33 pmLambert-St Louis
$273
Find similar

Frontier flights from St. Louis to Pennsylvania

Our best Frontier deals on St. Louis to Pennsylvania flight tickets
Frontier
Jan 26
STL8:22 pmLambert-St Louis
13h 52m
1 stop
PHL11:14 amPhiladelphia
Jan 27
PHL8:25 pmPhiladelphia
28h 08m
1 stop
STL11:33 pmLambert-St Louis
$130
Find similar
Frontier
Jan 20
STL5:42 pmLambert-St Louis
16h 07m
1 stop
EWR10:49 amNewark
Jan 23
EWR10:30 pmNewark
9h 21m
1 stop
STL6:51 amLambert-St Louis
$131
Find similar
Frontier
Jan 20
STL5:42 pmLambert-St Louis
16h 07m
1 stop
EWR10:49 amNewark
Jan 23
EWR10:30 pmNewark
9h 21m
1 stop
STL6:51 amLambert-St Louis
$133
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Pennsylvania that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated December 15, 2025.
Use the filters below to find and compare flights from St. Louis to Pennsylvania that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisPhiladelphia

STL - PHL

STLPHL

Lambert-St Louis

Mon 1/26

8:22 pm-11:14 am

1 stop13h 52m

Philadelphia

Tue 1/27

8:25 pm-11:33 pm

1 stop28h 08m

$130

St. LouisNewark

STL - EWR

STLEWR

Lambert-St Louis

Thu 1/8

3:43 pm-11:30 pm

1 stop6h 47m

Newark

Tue 1/13

5:40 pm-6:51 am

1 stop14h 11m

$130

St. LouisPittsburgh

STL - PIT

STLPIT

Lambert-St Louis

Thu 1/8

3:54 pm-11:29 pm

1 stop6h 35m

Pittsburgh

Sat 1/10

4:00 pm-10:44 pm

1 stop7h 44m

$191

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Thu 12/25

1:10 pm-4:10 pm

Nonstop2h 00m

Washington, D.C. Reagan-National

Thu 1/1

12:25 pm-1:45 pm

Nonstop2h 20m

$227

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Thu 12/25

8:15 am-11:24 am

Nonstop2h 09m

Washington, D.C. Dulles Intl

Wed 12/31

5:50 pm-7:22 pm

Nonstop2h 32m

$227

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Tue 1/13

8:20 am-11:15 am

Nonstop1h 55m

Washington, D.C. Reagan-National

Tue 1/20

12:00 pm-1:35 pm

Nonstop2h 35m

$231

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Tue 1/13

8:30 am-11:40 am

Nonstop2h 10m

Washington, D.C. Dulles Intl

Sat 1/17

8:40 am-10:13 am

Nonstop2h 33m

$231

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 1/7

9:54 am-12:59 pm

Nonstop2h 05m

Washington, D.C. Reagan-National

Sat 1/10

7:40 am-9:24 am

Nonstop2h 44m

$235

St. LouisNew York

STL - LGA

STLLGA

Lambert-St Louis

Tue 1/20

5:32 pm-9:00 pm

Nonstop2h 28m

New York LaGuardia

Thu 1/29

10:30 am-12:33 pm

Nonstop3h 03m

$267

St. LouisNew York

STL - LGA

STLLGA

Lambert-St Louis

Thu 2/12

6:00 am-11:45 am

1 stop4h 45m

New York LaGuardia

Tue 2/17

2:55 pm-4:52 pm

Nonstop2h 57m

$277

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Pennsylvania from

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

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 Pennsylvania?

The month of August is, on average, the cheapest month to fly to Pennsylvania from St. Louis, with most prices found around $277. If you don’t want to visit Pennsylvania in August, then you should wait until September to fly from St. Louis, when ticket prices are also cheap, with an average price of $340.

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

The cheapest day to depart on your flight to Pennsylvania is on a Thursday when prices can be found for as low as $629. 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 $951. These prices are subject to change though, so be sure to set up a Price Alert for flights to Pennsylvania.

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

Our most recent data shows that the best time of day to fly to Pennsylvania is in the evening. Flights from St. Louis to Pennsylvania during this time can be as low as $404. In contrast, the most expensive time of day to depart to Pennsylvania is at noon when prices are around $1,131.

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

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

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

You are more likely to see cheaper flights to Pennsylvania from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Pennsylvania for around $404 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Pennsylvania from St. Louis for as low as $310 on momondo.

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

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

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

You could potentially save up to 51% on your flight if you consider stops on a St. Louis to Pennsylvania flight.

Cheap St. Louis to Pennsylvania flight deals and tips

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

Best Price Found

$393

Fastest flight time

1h 35m

Direct flights

Every day

Airports in Pennsylvania

152 airports
The best one-way flight to Pennsylvania from St. Louis in the past 72 hours is $393. The best round-trip flight deal from St. Louis to Pennsylvania found on momondo in the last 72 hours is $537.
The fastest flight from St. Louis to Pennsylvania takes 1h 35m
Direct flights go from St. Louis to Pennsylvania every day.
There are 152 airports in Pennsylvania. From St. Louis there are direct flights to Washington, D.C. Reagan-National (DCA), Philadelphia (PHL), Pittsburgh (PIT), Washington, D.C. Dulles Intl (IAD).
Search flight deals

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

    Prices for flights from Lambert-St Louis Airport to Pennsylvania refresh daily.

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

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

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Pennsylvania.

  • What documentation or ID do you need to fly to Pennsylvania?

    The travel and health documents you'll need for your trip to Pennsylvania 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 Pennsylvania. 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 Pennsylvania?

Best airlines flying from St. Louis to Pennsylvania

Compare and see reviews for airlines that fly from St. Louis to Pennsylvania with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $130Free CancellationRating
5.8
3,080 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $132Free CancellationRating
6.3
8,187 reviews
Search Spirit Airlines flights
DeltaPriceFrom $172Free CancellationRating
7.9
8,008 reviews
Search Delta flights
American AirlinesPriceFrom $226Free CancellationRating
7.2
11,051 reviews
Search American Airlines flights
SouthwestPriceFrom $241Free CancellationRating
7.9
4,249 reviews
Search Southwest flights
United AirlinesPriceFrom $248Free CancellationRating
7.4
9,092 reviews
Search United Airlines flights

Why use momondo?

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

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

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

Yes. All flights to Pennsylvania from St. Louis on momondo can be compared and filtered by various policies on offer, including flexible booking.

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

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Pennsylvania from St. Louis.

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

Yes. momondo can track prices for St. Louis to Pennsylvania flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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