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$129+ Cheap flights from Portland, ME to St. Louis (PWM - STL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/2. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — STL
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
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Cheap flight deals from Portland to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Portland (PWM) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 11, 2025.

Round-trip from

$229
(United Airlines)

One-way from

$129
(American Airlines)

Popular in

December

Cheapest in

February

Average price

$349
From Portland to Lambert-St Louis
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One-way flight from Portland to Lambert-St Louis
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Highest demand for flights based on searches. 8% potential increase in price ($40 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($14 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Portland to St. Louis

Cheapest flights from Portland to St. Louis
Explore the most affordable flight options available from Portland to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

This United Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/306:00 amPWM - STL
1 stop5h 48mUnited Airlines
Tue 9/303:23 pmSTL - PWM
1 stop5h 21mUnited Airlines
Deal found 9/11$229
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/85:42 amPWM - STL
2 stops11h 13mDelta
Wed 10/156:40 amSTL - PWM
1 stop4h 20mDelta
Deal found 9/10$242
This American Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/165:59 pmPWM - STL
1 stop6h 59mAmerican Airlines
Sat 10/186:00 amSTL - PWM
1 stop5h 42mAmerican Airlines
Deal found 9/10$243
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/31:35 pmPWM - STL
1 stop5h 12mDelta
Mon 10/61:30 pmSTL - PWM
1 stop7h 49mDelta
Deal found 9/10$272
This Delta deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/291:27 pmPWM - STL
1 stop5h 35mDelta
Sun 11/25:00 amSTL - PWM
1 stop5h 32mDelta
Deal found 9/11$277
This American Airlines deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/86:00 amPWM - STL
1 stop5h 17mAmerican Airlines
Fri 12/122:04 pmSTL - PWM
1 stop6h 33mAmerican Airlines
Deal found 9/9$317
This Southwest deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/85:30 amPWM - STL
2 stops8h 05mSouthwest
Fri 12/125:10 amSTL - PWM
1 stop5h 00mSouthwest
Deal found 9/11$323

Cheapflights Fare Finder

 
Customize your flight search to find flights from Portland 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, Cheapflights users made 2,558,603 searches. Data last updated September 11, 2025.
Use the filters below to find and compare flights from Portland to St. Louis that are best for you.

Fly from

Portland

Fly to

St. Louis

Route

Depart

Return

Price

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Tue 9/30

6:00 am-12:51 pm

1 stop7h 51m

Lambert-St Louis

Tue 9/30

6:00 pm-11:45 pm

1 stop4h 45m

$229

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Tue 9/30

6:14 am-10:49 am

1 stop5h 35m

Lambert-St Louis

Tue 9/30

3:23 pm-11:59 pm

2 stops7h 36m

$234

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Wed 10/8

5:42 am-3:55 pm

2 stops11h 13m

Lambert-St Louis

Wed 10/15

6:40 am-12:00 pm

1 stop4h 20m

$242

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Fri 10/3

1:35 pm-5:47 pm

1 stop5h 12m

Lambert-St Louis

Mon 10/6

1:30 pm-10:19 pm

1 stop7h 49m

$272

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Fri 10/3

5:10 pm-11:07 pm

1 stop6h 57m

Lambert-St Louis

Mon 10/6

4:34 pm-10:45 pm

1 stop5h 11m

$272

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Mon 12/8

6:00 am-10:17 am

1 stop5h 17m

Lambert-St Louis

Fri 12/12

2:04 pm-9:37 pm

1 stop6h 33m

$272

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Wed 10/29

11:30 am-3:29 pm

1 stop4h 59m

Lambert-St Louis

Sun 11/2

4:10 pm-12:05 am

1 stop6h 55m

$277

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Thu 10/16

5:59 pm-11:58 pm

1 stop6h 59m

Lambert-St Louis

Sun 10/19

6:00 am-2:56 pm

1 stop7h 56m

$282

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Thu 10/2

3:28 pm-8:25 pm

1 stop5h 57m

$129

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Thu 10/16

5:59 pm-11:58 pm

1 stop6h 59m

$139

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/10

Showing 1-10 of 16 results
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Best time to book a flight from Portland to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Portland with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Portland to St. Louis

What is the cheapest month to book a flight from Portland, Maine to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Portland, Maine to St. Louis (average of $311). Flying from Portland, Maine to St. Louis in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from PWM to STL?

Find hourly flight availability from Portland to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 11, 2025.

When flying from Portland, Maine to St. Louis, the time of day you fly usually plays a role in the price. Save by searching for a flight in the afternoon, which can drop the price by up to 28% versus a flight at noon.

How much does it cost to fly round-trip from Portland, Maine to St. Louis?

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Louis. Reviews last updated September 11, 2025.
Get a feel of what it's like to fly with Southwest, Delta, and United Airlines from Portland to St. Louis by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,248 reviews

Entertainment

7.5

Food

7.0

Overall

8.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Southwest
8.0
Very good
4,248 reviews
Southwest
8.0
Very good
4,248 reviews

Entertainment

7.5

Food

7.0

Overall

8.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Delta
8.0
Very good
7,960 reviews
Southwest
8.0
Very good
4,248 reviews

Entertainment

7.5

Food

7.0

Overall

8.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
United Airlines
7.4
Good
8,937 reviews
Southwest
8.0
Very good
4,248 reviews

Entertainment

7.5

Food

7.0

Overall

8.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,248 reviews

Entertainment

7.5

Food

7.0

Overall

8.0

Comfort

8.0

Crew

8.6

Boarding

8.1

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines

Related info for your journey

Find useful and relevant information for your journey from Portland to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Portland, Maine to St. Louis?

    A quick flight from Portland, Maine to St. Louis can take about 5h 35m. American Airlines provides one of the quickest options available for as low as $234. Portland, Maine and St. Louis are separated by a distance of 1092 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from Portland, Maine to St. Louis round-trip?

    Flying on Delta is currently your cheapest option to St. Louis, with prices starting at $236. Additional round-trip tickets that might be worth considering are offered by American Airlines and United Airlines, with the lowest prices starting at $300 and $341, respectively. Delta is 41% cheaper than the average price of flights available within the next 90 days to this destination.

  • Can I find deals for flights from Portland to St. Louis that include hotel bookings?

    Yes. In addition to deals on Portland to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Portland to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Portland to St. Louis.

  • Can I find deals for business class flights from Portland to St. Louis?

    Yes. Cheapflights offers flight deals from Portland to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Portland, Maine to St. Louis?

    Currently, August is the cheapest month in which you can book a flight from Portland, Maine to St. Louis (average of $311). Flying from Portland, Maine to St. Louis in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

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Top 4 airlines flying from Portland to St. Louis

Discover the top 4 airlines that operate flights from Portland to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$236Average$383FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$300Average$426FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$341Average$466FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$371Average$417FlexibilityNo cancel feeOn-time63%

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