HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
St. Louis

$116+ 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 5/5. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — STL
May 4 — May 111
Sun 5/4
Sun 5/11
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Portland to St. Louis with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Portland to Lambert-St Louis are usually found in February or January, booked 10 days in advance, depart on a Tuesday or Friday and return on a Tuesday

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 April 29, 2025.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$285
(American Airlines)

One-way from

$116
(Mytrip)

Popular in

December

Cheapest in

February

Average price

$526
Provider with most accurate pricing for Portland-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Portland-Lambert-St Louis flights.
Search Deals
From Portland to Lambert-St Louis
Search Deals
One-way flight from Portland to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 3% potential increase in price ($16 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($11 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 2025
Search Deals

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 April 29, 2025.

This American Airlines deal was found by Cheapflights users on 4/28. 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 5/215:50 amPWM - STL
1 stop4h 52mAmerican Airlines
Wed 5/2810:25 amSTL - PWM
1 stop5h 26mAmerican Airlines
Deal found 4/28$285
This Delta deal was found by Cheapflights users on 4/28. 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 5/281:40 pmPWM - STL
2 stops10h 58mDelta
Wed 6/43:40 pmSTL - PWM
1 stop6h 41mDelta
Deal found 4/28$290
This Southwest deal was found by Cheapflights users on 4/28. 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.
Wed 5/286:15 amPWM - STL
1 stop7h 05mSouthwest
Sat 5/3112:20 pmSTL - PWM
2 stops10h 05mSouthwest
Deal found 4/28$381
This United Airlines deal was found by Cheapflights users on 4/28. 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 6/2412:15 pmPWM - STL
2 stops11h 30mUnited Airlines
Sat 6/287:55 amSTL - PWM
2 stops9h 18mUnited Airlines
Deal found 4/28$508
This Mytrip deal was found by Cheapflights users on 4/29. 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.
Mon 5/1911:50 amPWM - STL
3 stops31h 51mMultiple Airlines
Thu 5/2210:10 amSTL - PWM
2 stops26h 57mMultiple Airlines
Deal found 4/29$599

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 April 29, 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 5/21

5:50 am-9:42 am

1 stop4h 52m

Lambert-St Louis

Wed 5/28

10:25 am-4:51 pm

1 stop5h 26m

$285

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Wed 5/28

1:40 pm-11:38 pm

2 stops10h 58m

Lambert-St Louis

Wed 6/4

3:40 pm-11:21 pm

1 stop6h 41m

$290

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Wed 5/28

6:15 am-12:20 pm

1 stop7h 05m

Lambert-St Louis

Sat 5/31

12:20 pm-11:25 pm

2 stops10h 05m

$381

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Tue 6/24

12:15 pm-10:45 pm

2 stops11h 30m

Lambert-St Louis

Sat 6/28

7:55 am-6:13 pm

2 stops9h 18m

$508

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Mon 5/19

11:50 am-6:41 pm

3 stops31h 51m

Lambert-St Louis

Thu 5/22

10:10 am-2:07 pm

2 stops26h 57m

$599

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Mon 5/5

9:30 pm-12:06 am

1 stop27h 36m

$116

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Mon 5/5

6:00 am-3:47 pm

2 stops10h 47m

$325

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Fri 5/9

5:30 am-1:19 pm

2 stops8h 49m

$379

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Mon 5/5

6:16 pm-5:15 pm

3 stops23h 59m

$390

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/28

Compare providers for flights from Portland to St. Louis

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Portland to St. Louis in April.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
GotogatePrice Accuracy3 starsTrust Score*2 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
FlightnetworkPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Portland, Maine-St. Louis flights, users find the pricing of Mytrip to be most consistent on Cheapflights vs. Mytrip Users can find the same prices on Portland, Maine-St. Louis flight deals on Cheapflights vs. Mytrip >95% of the time. Price accuracy is based on data collected from Portland, Maine-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Portland, Maine-St. Louis flights, Cheapflights users trust Mytrip the most. Mytrip has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Portland, Maine-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

How far ahead should I book a flight from Portland, Maine to St. Louis?

Use this chart to determine the optimal time to book a round-trip flight from Portland to St. Louis. Price data was last updated on April 25, 2025.

The price you pay for your flight from Portland, Maine to St. Louis may vary depending on when you book. For the best chance of a lower fare, look to book 10 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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 April 29, 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.

Rainfall in St. Louis by month

Plan your trip to St. Louis by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in St. Louis ranges from 2.2 - 4.7 inches per month. May is typically the wettest month, when rainfall can reach 4.7 in. February is typically the driest time to visit St. Louis when rainfall is around 2.2 in.

Temperature in St. Louis by month

Plan your trip to St. Louis by taking into account the average temperature totals by month.

If weather is an important factor for your trip to St. Louis, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 32.0 F).

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 April 29, 2025.
Peruse reviews from past customers who have flown with Southwest, Delta and United Airlines from Portland to St. Louis to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,295 reviews

Food

7.1

Comfort

8.0

Boarding

8.2

Entertainment

7.6

Overall

8.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

Gina,Apr 2025

LAS - DEN

Good, the crew was friendly and helpful. The pilot had great skills in keeping the plane stable through rough turbulence. Smooth landing, too! Thank you!
Southwest
8.0
Very good
4,295 reviews
Southwest
8.0
Very good
4,295 reviews

Food

7.1

Comfort

8.0

Boarding

8.2

Entertainment

7.6

Overall

8.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

Gina,Apr 2025

LAS - DEN

Good, the crew was friendly and helpful. The pilot had great skills in keeping the plane stable through rough turbulence. Smooth landing, too! Thank you!
Delta
8.0
Very good
7,929 reviews
Southwest
8.0
Very good
4,295 reviews

Food

7.1

Comfort

8.0

Boarding

8.2

Entertainment

7.6

Overall

8.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

Gina,Apr 2025

LAS - DEN

Good, the crew was friendly and helpful. The pilot had great skills in keeping the plane stable through rough turbulence. Smooth landing, too! Thank you!
United Airlines
7.4
Good
8,696 reviews
Southwest
8.0
Very good
4,295 reviews

Food

7.1

Comfort

8.0

Boarding

8.2

Entertainment

7.6

Overall

8.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

Gina,Apr 2025

LAS - DEN

Good, the crew was friendly and helpful. The pilot had great skills in keeping the plane stable through rough turbulence. Smooth landing, too! Thank you!
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,295 reviews

Food

7.1

Comfort

8.0

Boarding

8.2

Entertainment

7.6

Overall

8.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

Gina,Apr 2025

LAS - DEN

Good, the crew was friendly and helpful. The pilot had great skills in keeping the plane stable through rough turbulence. Smooth landing, too! Thank you!
Frontier
6.0
Okay
3,284 reviews
Southwest
8.0
Very good
4,295 reviews

Food

7.1

Comfort

8.0

Boarding

8.2

Entertainment

7.6

Overall

8.0

Crew

8.6

Reviews

1 / 20
10.0
Excellent

Gina,Apr 2025

LAS - DEN

Good, the crew was friendly and helpful. The pilot had great skills in keeping the plane stable through rough turbulence. Smooth landing, too! Thank you!

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 $285. Additional round-trip tickets that might be worth considering are offered by Delta and Southwest, with the lowest prices starting at $290 and $381, respectively. American Airlines is 33% 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 Frontier. According to our data, you can fly for as low as $116. Users have also found prices from $325 and $379 on United Airlines and Delta, 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 Portland?

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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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 April 29, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$308Average$422FlexibilityNo cancel feeOn-time71%
DeltaCheapest$333Average$455FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$341Average$466FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$351Average$417FlexibilityNo cancel feeOn-time63%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.