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Cheap flights from Pennsylvania to St. Louis from $72

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Pennsylvania to St. Louis departing on 10/23. 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 Pennsylvania to St. Louis

Cheap round-trip flights

Frontier Logo
6:10 am - 3:04 pmIAD-STL
9h 54m1 stop
Frontier Logo
1:57 pm - 6:24 pmSTL-IAD
27h 27m1 stop
$143Frontier
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Thu, Sep 4 - Fri, Sep 5
Frontier Logo
6:30 am - 3:04 pmLGA-STL
9h 34m1 stop
Frontier Logo
10:39 am - 8:59 pmSTL-LGA
9h 20m1 stop
$152Frontier
Find Deal
Thu, Sep 25 - Sun, Sep 28
American Airlines Logo
5:06 pm - 11:54 pmPIT-STL
7h 48m1 stop
American Airlines Logo
6:00 am - 2:42 pmSTL-PIT
7h 42m1 stop
$171American Airlines
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Tue, Oct 7 - Thu, Oct 9
United Airlines Logo
8:40 am - 10:02 amIAD-STL
2h 22mnonstop
United Airlines Logo
1:10 pm - 4:20 pmSTL-IAD
2h 10mnonstop
$173United Airlines
Find Deal
Wed, Sep 3 - Mon, Sep 8
Southwest Logo
3:20 pm - 4:40 pmDCA-STL
2h 20mnonstop
Southwest Logo
6:30 pm - 9:35 pmSTL-DCA
2h 05mnonstop
$173Southwest
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Thu, Sep 25 - Sat, Sep 27
American Airlines Logo
12:35 pm - 8:32 pmPIT-STL
8h 57m1 stop
American Airlines Logo
6:05 am - 12:16 pmSTL-PIT
5h 11m1 stop
$174American Airlines
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Thu, Sep 4 - Sun, Sep 7
Southwest Logo
6:20 am - 8:50 amPIT-STL
3h 30m1 stop
Southwest Logo
8:15 am - 10:50 amSTL-PIT
1h 35mnonstop
$177Southwest
Find Deal
Thu, Oct 2 - Mon, Oct 6
United Airlines Logo
5:53 pm - 11:44 pmIAD-STL
6h 51m1 stop
United Airlines Logo
8:15 am - 11:25 amSTL-IAD
2h 10mnonstop
$183United Airlines
Find Deal
Mon, Sep 8 - Wed, Sep 10
Logo
5:54 am - 10:37 amEWR-STL
5h 43m1 stop
Logo
10:57 am - 11:31 pmSTL-EWR
11h 34m1 stop
$188
Find Deal
Fri, Oct 10 - Tue, Oct 14
Logo
5:55 am - 3:04 pmEWR-STL
10h 09m1 stop
Logo
10:35 am - 5:51 pmSTL-EWR
6h 16m1 stop
$204
Find Deal
Thu, Sep 18 - Sun, Sep 21

American Airlines flights from Pennsylvania to St. Louis

Our best American Airlines deals on Pennsylvania to St. Louis flight tickets
American Airlines
Oct 7
PIT5:06 pmPittsburgh
7h 48m
1 stop
STL11:54 pmLambert-St Louis
Oct 9
STL6:00 amLambert-St Louis
7h 42m
1 stop
PIT2:42 pmPittsburgh
$171
Find similar
American Airlines
Sep 4
PIT12:35 pmPittsburgh
8h 57m
1 stop
STL8:32 pmLambert-St Louis
Sep 7
STL6:05 amLambert-St Louis
5h 11m
1 stop
PIT12:16 pmPittsburgh
$174
Find similar
American Airlines
Sep 16
PHL7:19 pmPhiladelphia
2h 47m
STL9:06 pmLambert-St Louis
Sep 18
STL6:00 amLambert-St Louis
2h 18m
PHL9:18 amPhiladelphia
$203
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Delta flights from Pennsylvania to St. Louis

Our best Delta deals on Pennsylvania to St. Louis flight tickets
Delta
Sep 9
JFK2:59 pmNew York John F Kennedy Intl
2h 50m
STL4:49 pmLambert-St Louis
Sep 17
STL4:10 pmLambert-St Louis
2h 48m
JFK7:58 pmNew York John F Kennedy Intl
$189
Find similar
Delta
Oct 3
PIT7:12 amPittsburgh
6h 19m
1 stop
STL12:31 pmLambert-St Louis
Oct 5
STL6:01 amLambert-St Louis
5h 34m
1 stop
PIT12:35 pmPittsburgh
$197
Find similar
Delta
Oct 6
LGA6:30 amNew York LaGuardia
2h 43m
STL8:13 amLambert-St Louis
Oct 21
STL5:40 pmLambert-St Louis
2h 23m
LGA9:03 pmNew York LaGuardia
$203
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Pennsylvania to St. Louis 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 August 14, 2025.
Use the filters below to find and compare flights from Pennsylvania to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 9/4

6:10 am-3:04 pm

1 stop9h 54m

Lambert-St Louis

Fri 9/5

1:57 pm-6:24 pm

1 stop27h 27m

$143

New YorkSt. Louis

LGA - STL

LGASTL

New York LaGuardia

Thu 9/25

6:30 am-3:04 pm

1 stop9h 34m

Lambert-St Louis

Sun 9/28

10:39 am-8:59 pm

1 stop9h 20m

$152

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Tue 10/7

5:06 pm-11:54 pm

1 stop7h 48m

Lambert-St Louis

Thu 10/9

6:00 am-2:42 pm

1 stop7h 42m

$171

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Wed 9/3

8:40 am-10:02 am

Nonstop2h 22m

Lambert-St Louis

Mon 9/8

1:10 pm-4:20 pm

Nonstop2h 10m

$173

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 9/25

3:20 pm-4:40 pm

Nonstop2h 20m

Lambert-St Louis

Sat 9/27

6:30 pm-9:35 pm

Nonstop2h 05m

$173

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Thu 9/4

12:35 pm-8:32 pm

1 stop8h 57m

Lambert-St Louis

Sun 9/7

6:05 am-12:16 pm

1 stop5h 11m

$174

PittsburghSt. Louis

PIT - STL

PITSTL

Pittsburgh

Thu 10/2

6:20 am-8:50 am

1 stop3h 30m

Lambert-St Louis

Mon 10/6

8:15 am-10:50 am

Nonstop1h 35m

$177

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Mon 9/8

5:53 pm-11:44 pm

1 stop6h 51m

Lambert-St Louis

Wed 9/10

8:15 am-11:25 am

Nonstop2h 10m

$183

NewarkSt. Louis

EWR - STL

EWRSTL

Newark

Fri 10/10

5:54 am-10:37 am

1 stop5h 43m

Lambert-St Louis

Tue 10/14

10:57 am-11:31 pm

1 stop11h 34m

$188

NewarkSt. Louis

EWR - STL

EWRSTL

Newark

Thu 9/18

5:55 am-3:04 pm

1 stop10h 09m

Lambert-St Louis

Sun 9/21

10:35 am-5:51 pm

1 stop6h 16m

$204

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 St. Louis from

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

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 St. Louis?

In general, August is the cheapest month to fly from Pennsylvania to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $316. The month of September is another great option to travel to St. Louis, with average flight prices from Pennsylvania averaging around $338.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $391. 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 $465. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Pennsylvania in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $386 when looking at flights departing in the afternoon. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $422 per ticket.

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

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

How far in advance should I book a flight to St. Louis?

You are more likely to see cheaper flights to St. Louis from Pennsylvania when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $397 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Pennsylvania for as low as $338 on momondo.

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

There are 3 cabin classes available to choose from on Pennsylvania 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.

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

You could potentially save up to 40% on your flight if you consider stops on a Pennsylvania to St. Louis flight.

Cheap Pennsylvania to St. Louis flight deals and tips

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

Best Price Found

$72

Fastest flight time

1h 45m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Pennsylvania in the past 72 hours is $72. The best round-trip flight deal from Pennsylvania to St. Louis found on momondo in the last 72 hours is $143.
The fastest flight from Pennsylvania to St. Louis takes 1h 45m
Direct flights go from Pennsylvania to St. Louis every day.
There is 1 airport near St. Louis: Lambert-St Louis (STL)
Search flight deals

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

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

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

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

    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 Pennsylvania to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

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

Best airlines flying from Pennsylvania to St. Louis

Compare and see reviews for airlines that fly from Pennsylvania to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $75Free CancellationRating
5.8
3,219 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $95Free CancellationRating
6.3
8,045 reviews
Search Spirit Airlines flights
American AirlinesPriceFrom $177Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
United AirlinesPriceFrom $236Free CancellationRating
7.4
8,916 reviews
Search United Airlines flights
DeltaPriceFrom $238Free CancellationRating
8.0
7,980 reviews
Search Delta flights
SouthwestPriceFrom $244Free CancellationRating
8.0
4,244 reviews
Search Southwest flights

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Fairview Heights
Hermann
Maryland Heights
Florissant
O'Fallon
Fenton
Wentzville
Collinsville
Alton
St. Peters
Farmington
Festus
Glencoe
Eureka
Clayton
Edwardsville
Litchfield
Shrewsbury

Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Pennsylvania to St. Louis. Millions of users trust and use momondo every year so you are in good hands.

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

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

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

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 St. Louis from Pennsylvania.

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

Yes momondo offers price alerts on flights to St. Louis from Pennsylvania. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

An easier way to manage your St. Louis trip

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