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$127+ Cheap flights from St. Louis to Portland, ME (STL - PWM)

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 8/22. Fares are subject to change and may not be available on all flights or dates of travel.
STL — PWM
Aug 3 — Aug 101
Sun 8/3
Sun 8/10
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to Portland are usually found in January or November, booked 58 days in advance, depart on a Tuesday or Saturday and return on a Tuesday

Cheap flight deals from St. Louis to Portland

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Portland (PWM). 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 29, 2025.

Round-trip from

$297
(American Airlines)

One-way from

$127
(FlightHub)

Popular in

June

Cheapest in

January

Average price

$396
From Lambert-St Louis to Portland
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One-way flight from Lambert-St Louis to Portland
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Highest demand for flights based on searches. 5% potential increase in price ($25 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Find flight deals from St. Louis to Portland

Cheapest flights from St. Louis to Portland
Explore the most affordable flight options available from St. Louis to Portland. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 29, 2025.

This American Airlines deal was found by Cheapflights users on 7/26. 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 9/106:00 amSTL - PWM
1 stop6h 31mAmerican Airlines
Wed 9/175:20 pmPWM - STL
1 stop4h 50mAmerican Airlines
Deal found 7/26$297
This Delta deal was found by Cheapflights users on 7/28. 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 9/101:26 pmSTL - PWM
2 stops8h 59mDelta
Wed 9/176:00 amPWM - STL
1 stop7h 21mDelta
Deal found 7/28$302
This Southwest deal was found by Cheapflights users on 7/28. 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 9/172:15 pmSTL - PWM
1 stop7h 10mSouthwest
Sun 9/215:35 amPWM - STL
2 stops7h 10mSouthwest
Deal found 7/28$403
This United Airlines deal was found by Cheapflights users on 7/27. 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.
Mon 8/116:00 amSTL - PWM
1 stop6h 20mUnited Airlines
Fri 8/154:56 pmPWM - STL
1 stop6h 49mUnited Airlines
Deal found 7/27$527

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Portland 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 29, 2025.
Use the filters below to find and compare flights from St. Louis to Portland that are best for you.

Fly from

St. Louis

Fly to

Portland

Route

Depart

Return

Price

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Wed 9/10

10:54 am-4:34 pm

1 stop4h 40m

Portland

Wed 9/17

6:00 am-12:51 pm

1 stop7h 51m

$297

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Wed 9/10

1:26 pm-11:25 pm

2 stops8h 59m

Portland

Wed 9/17

6:00 am-12:21 pm

1 stop7h 21m

$302

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Wed 9/17

2:15 pm-10:25 pm

1 stop7h 10m

Portland

Sun 9/21

5:35 am-11:45 am

2 stops7h 10m

$403

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Mon 8/11

6:00 am-1:20 pm

1 stop6h 20m

Portland

Fri 8/15

4:56 pm-10:45 pm

1 stop6h 49m

$527

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Fri 8/22

3:16 pm-12:46 pm

1 stop20h 30m

$127

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Sat 10/11

4:10 pm-12:05 am

1 stop6h 55m

$149

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Sat 10/11

12:25 pm-11:20 pm

2 stops9h 55m

$194

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Sun 8/24

4:54 pm-10:59 pm

1 stop5h 05m

$204

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Mon 8/11

10:47 am-12:13 pm

3 stops24h 26m

$271

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Thu 8/21

2:45 pm-11:20 pm

2 stops7h 35m

$296

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/28

Best time to book a flight from St. Louis to Portland

Have a flexible travel schedule? Discover the best time to fly to Portland from St. Louis 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 St. Louis to Portland

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

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

The price you pay for your flight from St. Louis to Portland, Maine may vary depending on when you book. For the best chance of a lower fare, look to book 58 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 St. Louis to Portland, Maine?

Currently, January is the cheapest month in which you can book a flight from St. Louis to Portland, Maine (average of $296). Flying from St. Louis to Portland, Maine in July is currently the most expensive (average of $394). 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 STL to PWM?

Find hourly flight availability from St. Louis to Portland. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 29, 2025.

When flying from St. Louis to Portland, Maine, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 35% versus a flight at noon.

What’s the top layover airport for flights from St. Louis to Portland, Maine?

Share of 1-stop round-trip flights from St. Louis to Portland, Maine chosen by Cheapflights users in the past 12 months, using the same layover each way.

Baltimore (BWI) – chosen by Cheapflights users on 67% of 1-stop itineraries from St. Louis to Portland, Maine on Cheapflights.

What’s the cheapest layover airport for flights from St. Louis to Portland, Maine?

Average round-trip fare for 1-stop flights from St. Louis to Portland, Maine, chosen by Cheapflights users in the past 12 months, with the same layover each way.

Baltimore (BWI) is the most affordable 1-stop option, with an average round-trip price of $295.

What’s the fastest layover option from St. Louis to Portland, Maine?

Shortest average travel time for 1-stop one-way flights from St. Louis to Portland, Maine, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.

Flights via Newark (EWR) have the shortest average one-way travel time for 1-stop routes: 2h 14m.

Which airport typically offers the quickest layover for flights from St. Louis to Portland, Maine?

Average layover duration for 1-stop one-way flights from St. Louis to Portland, Maine, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Newark (EWR) offer the fastest connection on this route, with an average layover time of 1h 08m.

Reviews of airlines servicing Portland

Get insights into the airlines that provide service to Portland. 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 Portland. Reviews last updated July 29, 2025.
See what other customers who have flown with Southwest, Delta, and United Airlines from St. Louis to Portland have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,238 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
Southwest
8.0
Very good
4,238 reviews
Southwest
8.0
Very good
4,238 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
Delta
8.0
Very good
7,977 reviews
Southwest
8.0
Very good
4,238 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
United Airlines
7.4
Good
8,899 reviews
Southwest
8.0
Very good
4,238 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,238 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
Frontier
5.9
Fair
3,238 reviews
Southwest
8.0
Very good
4,238 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Portland. 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 St. Louis to Portland, Maine round-trip?

    According to our current data, American Airlines ($297), Delta ($302), and Southwest ($403) offers the cheapest pricing from St. Louis to Portland, Maine. These flights start at 27% lower than the current average price 3 months from now.

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

    $127 is the cheapest one-way deal found within the past few days, from Frontier. You may also be able to find cheap deals on Delta and United Airlines, with prices starting from $149 and $194, respectively.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from St. Louis to Portland 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 St. Louis to Portland, Maine?

    Currently, January is the cheapest month in which you can book a flight from St. Louis to Portland, Maine (average of $296). Flying from St. Louis to Portland, Maine in July is currently the most expensive (average of $394). 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
Brunswick
North Conway
Auburn
Conway
Lewiston

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Top 4 airlines flying from St. Louis to Portland

Discover the top 4 airlines that operate flights from St. Louis to Portland. 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 29, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$296Average$398FlexibilityNo cancel feeOn-time71%
DeltaCheapest$300Average$393FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$308Average$451FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$336Average$506FlexibilityNo cancel feeOn-time69%

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