St. Louis

$143+ 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 9/4. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — STL
Jul 30 — Aug 61
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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 July 25, 2025.

Round-trip from

$282
(American Airlines)

One-way from

$143
(American Airlines)

Popular in

December

Cheapest in

February

Average price

$432
From Portland to Lambert-St Louis
One-way flight from Portland to Lambert-St Louis
Highest demand for flights based on searches. 8% potential increase in price ($38 potential increase over avg. RT price).
Cheapest flight prices on average. 3% potential price decrease ($14 potential savings vs. average RT price).
Average for round-trip flights in July 2025

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 July 25, 2025.

This American Airlines deal was found by Cheapflights users on 7/24. 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.
Wed 10/156:00 amPWM - STL
1 stop5h 24mAmerican Airlines
Sat 10/186:00 amSTL - PWM
1 stop7h 56mAmerican Airlines
Deal found 7/24$282
This Delta deal was found by Cheapflights users on 7/24. 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 10/156:30 amPWM - STL
2 stops10h 28mDelta
Sat 10/181:30 pmSTL - PWM
1 stop7h 28mDelta
Deal found 7/24$290
This Southwest deal was found by Cheapflights users on 7/24. 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.
Thu 10/165:45 amPWM - STL
2 stops10h 10mSouthwest
Tue 10/2112:30 pmSTL - PWM
2 stops9h 00mSouthwest
Deal found 7/24$386
This Mytrip deal was found by Cheapflights users on 7/22. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/612:38 pmPWM - STL
3 stops22h 14mMultiple Airlines
Sun 8/1010:47 amSTL - PWM
3 stops23h 58mMultiple Airlines
Deal found 7/22$632
This United Airlines deal was found by Cheapflights users on 7/24. 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.
Fri 8/86:20 pmPWM - STL
1 stop5h 25mUnited Airlines
Tue 8/123:20 pmSTL - PWM
1 stop5h 41mUnited Airlines
Deal found 7/24$682

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 July 25, 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

Wed 10/15

6:00 am-10:24 am

1 stop5h 24m

Lambert-St Louis

Sat 10/18

6:00 am-2:56 pm

1 stop7h 56m

$282

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Wed 10/15

6:30 am-3:58 pm

2 stops10h 28m

Lambert-St Louis

Sat 10/18

1:30 pm-9:58 pm

1 stop7h 28m

$290

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Thu 10/16

5:45 am-2:55 pm

2 stops10h 10m

Lambert-St Louis

Tue 10/21

12:30 pm-10:30 pm

2 stops9h 00m

$386

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Fri 8/8

12:52 pm-2:39 pm

3 stops26h 47m

Lambert-St Louis

Tue 8/12

9:50 am-11:53 am

3 stops25h 03m

$660

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Fri 8/8

6:20 pm-10:45 pm

1 stop5h 25m

Lambert-St Louis

Tue 8/12

5:00 am-1:19 pm

2 stops7h 19m

$664

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Thu 9/4

6:00 am-12:23 pm

1 stop7h 23m

$143

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Thu 9/4

6:00 am-2:37 pm

2 stops9h 37m

$148

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Tue 10/14

5:45 am-1:50 pm

2 stops9h 05m

$195

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Mon 8/18

6:10 am-3:47 pm

1 stop10h 37m

$233

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Sun 8/3

1:10 pm-9:52 am

3 stops21h 42m

$296

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/24

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 July 25, 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.

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 July 25, 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.

Food

7.0

Boarding

8.1

Overall

8.0

Comfort

8.0

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

Food

7.0

Boarding

8.1

Overall

8.0

Comfort

8.0

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.
8.0
Very good

Food

7.0

Boarding

8.1

Overall

8.0

Comfort

8.0

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

Food

7.0

Boarding

8.1

Overall

8.0

Comfort

8.0

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

Food

7.0

Boarding

8.1

Overall

8.0

Comfort

8.0

Entertainment

7.6

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

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

    Flying on American Airlines is currently your cheapest option to St. Louis, with prices starting at $282. Additional round-trip tickets that might be worth considering are offered by Delta and Southwest, with the lowest prices starting at $290 and $386, respectively. American Airlines is 31% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from Portland, Maine to St. Louis one-way?

    For one-way options, check prices for American Airlines. According to our data, you can fly for as low as $143. Users have also found prices from $148 and $195 on Delta and Southwest, respectively.

  • 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
O'Fallon
Maryland Heights
Fairview Heights
Collinsville
Eureka
St. Peters
Glencoe
Alton
Festus
Chesterfield
Farmington

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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 July 25, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$236Average$406FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$308Average$441FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$341Average$466FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$351Average$417FlexibilityNo cancel feeOn-time63%

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