What is the cheapest airline that flies from Lambert-St Louis to Portland?

United Airlines, Delta, and Southwest are the most popular carriers operating from Lambert-St Louis to Portland

What airlines fly to Portland, Maine?

American Airlines, Southwest and Delta are the top three most popular airlines that fly to Portland, Maine from St. Louis according to our data. American Airlines is the first choice among our users, with 52% of people opting to fly with this airline when traveling to Portland, Maine. Keep in mind that there are 6 different airlines that fly to Portland, Maine on a routine basis, so you have a few additional options to choose from.

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

Prices for flights from Lambert-St Louis Airport to Portland Airport are refreshed on a daily basis.

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

The number of operators available for flights from Lambert-St Louis Airport to Portland Airport is 4 as of September 2026.

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

The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Lambert-St Louis Airport to Portland Airport.

What documentation or ID do you need to fly to Portland Airport?

The travel and health documents you'll need for your trip to Portland Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Portland Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

$133 Cheap Flights from St. Louis to Portland, Maine in 2026/27

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from St. Louis to Portland

Round-trip

One-way

Last minute

Cheap round-trip flights

Enter your travel dates to find the best prices.

6:25 am - 12:25 pmSTL Lambert-St Louis-PWM Portland

5h 00m1 stop Baltimore/Washington

3:25 pm - 10:10 pmPWM Portland-STL Lambert-St Louis

7h 45m1 stop Baltimore/Washington

$282Southwest

Sat, Dec 5 - Tue, Dec 15

6:25 am - 2:45 pmSTL Lambert-St Louis-PWM Portland

7h 20m1 stop Baltimore/Washington

5:15 am - 12:40 pmPWM Portland-STL Lambert-St Louis

8h 25m2 stops Baltimore/Washington Chicago Midway

$286Southwest

Sat, Dec 5 - Tue, Dec 15

6:00 am - 11:56 amSTL Lambert-St Louis-PWM Portland

4h 56m1 stop Chicago O'Hare Intl

3:25 pm - 7:37 pmPWM Portland-STL Lambert-St Louis

5h 12m1 stop Washington, D.C. Reagan-National

$291American Airlines

Tue, Dec 1 - Sat, Dec 12

6:00 am - 11:56 amSTL Lambert-St Louis-PWM Portland

4h 56m1 stop Chicago O'Hare Intl

3:25 pm - 7:37 pmPWM Portland-STL Lambert-St Louis

5h 12m1 stop Washington, D.C. Reagan-National

$339American Airlines

Tue, Dec 1 - Sat, Dec 12

10:35 am - 4:02 pmSTL Lambert-St Louis-PWM Portland

4h 27m1 stop Detroit Metropolitan Wayne County

6:00 am - 1:23 pmPWM Portland-STL Lambert-St Louis

8h 23m1 stop Atlanta Hartsfield-Jackson

$339Delta

Sat, Nov 7 - Tue, Nov 10

2:25 pm - 9:00 pmSTL Lambert-St Louis-PWM Portland

5h 35m1 stop Atlanta Hartsfield-Jackson

6:01 am - 10:51 amPWM Portland-STL Lambert-St Louis

5h 50m1 stop Atlanta Hartsfield-Jackson

$339Delta

Sat, Oct 10 - Tue, Oct 13

7:30 am - 2:16 pmSTL Lambert-St Louis-PWM Portland

5h 46m1 stop Chicago O'Hare Intl

8:29 am - 3:43 pmPWM Portland-STL Lambert-St Louis

8h 14m1 stop Chicago O'Hare Intl

$339United Airlines

Sat, Oct 31 - Mon, Nov 2

9:04 am - 6:12 pmSTL Lambert-St Louis-PWM Portland

8h 08m2 stops Chicago O'Hare Intl Newark

5:08 pm - 9:40 pmPWM Portland-STL Lambert-St Louis

5h 32m1 stop Chicago O'Hare Intl

$344United Airlines

Tue, Oct 20 - Tue, Oct 27

4:30 pm - 9:08 amSTL Lambert-St Louis-PWM Portland

15h 38m1 stop Orlando

7:00 am - 5:40 pmPWM Portland-STL Lambert-St Louis

11h 40m2 stops Cincinnati Cinci./N. Kentucky Atlanta Hartsfield-Jackson

$511Multiple Airlines

Thu, Oct 15 - Mon, Oct 19

5:19 pm - 9:08 amSTL Lambert-St Louis-PWM Portland

14h 49m1 stop Orlando

5:09 pm - 1:10 pmPWM Portland-STL Lambert-St Louis

21h 01m2 stops Raleigh-Durham Atlanta Hartsfield-Jackson

$541Multiple Airlines

Fri, Oct 2 - Tue, Oct 6

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Southwest flights from St. Louis to Portland, Maine

Our best Southwest deals on St. Louis to Portland, Maine flight tickets

Southwest

Dec 5

STL6:25 amLambert-St Louis

5h 00m

1 stop

PWM12:25 pmPortland

Dec 15

PWM3:25 pmPortland

7h 45m

1 stop

STL10:10 pmLambert-St Louis

$282

Southwest

Dec 5

STL6:25 amLambert-St Louis

7h 20m

1 stop

PWM2:45 pmPortland

Dec 15

PWM5:15 amPortland

8h 25m

2 stops

STL12:40 pmLambert-St Louis

$286

Southwest

Dec 5

STL6:25 amLambert-St Louis

7h 20m

1 stop

PWM2:45 pmPortland

Dec 15

PWM5:15 amPortland

8h 25m

2 stops

STL12:40 pmLambert-St Louis

$344

Delta flights from St. Louis to Portland, Maine

Our best Delta deals on St. Louis to Portland, Maine flight tickets

Delta

Dec 1

STL2:33 pmLambert-St Louis

8h 01m

1 stop

PWM11:34 pmPortland

Dec 12

PWM6:00 amPortland

6h 29m

1 stop

STL11:29 amLambert-St Louis

$339

Delta

Dec 3

STL6:32 amLambert-St Louis

4h 25m

1 stop

PWM11:57 amPortland

Dec 13

PWM6:00 amPortland

6h 29m

1 stop

STL11:29 amLambert-St Louis

$379

Delta

Oct 1

STL6:40 amLambert-St Louis

4h 30m

1 stop

PWM12:10 pmPortland

Oct 3

PWM12:36 pmPortland

5h 16m

1 stop

STL4:52 pmLambert-St Louis

$537

momondo Fare Finder

Use the filters below to find and compare flights from St. Louis to Portland, Maine that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Sat 12/5

6:25 am-12:25 pm

1 stop5h 00m

Portland

Tue 12/15

3:25 pm-10:10 pm

1 stop7h 45m

$282

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Sat 12/5

6:25 am-2:45 pm

1 stop7h 20m

Portland

Tue 12/15

5:15 am-12:40 pm

2 stops8h 25m

$286

Quickest round-trip

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Tue 12/1

6:00 am-11:56 am

1 stop4h 56m

Portland

Sat 12/12

3:25 pm-7:37 pm

1 stop5h 12m

$291

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Tue 12/1

6:00 am-11:56 am

1 stop4h 56m

Portland

Sat 12/12

3:25 pm-7:37 pm

1 stop5h 12m

$339

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Sat 11/7

10:35 am-4:02 pm

1 stop4h 27m

Portland

Tue 11/10

6:00 am-1:23 pm

1 stop8h 23m

$339

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Sat 10/10

2:25 pm-9:00 pm

1 stop5h 35m

Portland

Tue 10/13

6:01 am-10:51 am

1 stop5h 50m

$339

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Sat 10/31

7:30 am-2:16 pm

1 stop5h 46m

Portland

Mon 11/2

8:29 am-3:43 pm

1 stop8h 14m

$339

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Tue 10/20

9:04 am-6:12 pm

2 stops8h 08m

Portland

Tue 10/27

5:08 pm-9:40 pm

1 stop5h 32m

$344

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Thu 10/15

4:30 pm-9:08 am

1 stop15h 38m

Portland

Mon 10/19

7:00 am-5:40 pm

2 stops11h 40m

$511

St. LouisPortland

STL Lambert-St Louis - PWM Portland

STLPWM

Lambert-St Louis

Fri 10/2

5:19 pm-9:08 am

1 stop14h 49m

Portland

Tue 10/6

5:09 pm-1:10 pm

2 stops21h 01m

$541

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from St. Louis to Portland, Maine

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

Prices

Airlines

What is the typical price of a round-trip flight between St. Louis and Portland, Maine?

Prices are currently low for flights on this route.

Typical prices usually range from $388 to $498.
The lowest price recently found on this route was $281.

What is the cheapest month to fly to Portland, Maine?

The cheapest month to fly to Portland, Maine from St. Louis is in March. Flight prices, which tend to average around $349, are often lower during this time because this is during the off-season. If you aren’t able to travel to Portland, Maine during the month of March, then flying in November is also cheap. Prices for this month can be found on momondo for an average of $379.

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

You are more likely to see cheaper flights to Portland, Maine from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Portland, Maine for around $438 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Portland, Maine from St. Louis for as low as $363 on momondo.

Can stopping save me money on St. Louis to Portland, Maine flights?

You could potentially save up to 22% on your flight if you consider stops on a St. Louis to Portland, Maine flight.

How have St. Louis to Portland, Maine flight prices changed over time?

As of September 2026, prices for St. Louis to Portland, Maine flights are approximately 2% cheaper when compared to flights at the same time last year.

When to book flights from St. Louis to Portland, Maine

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Portland, Maine according to our flight data. Find out which month and days have the cheapest flights.

Estimated round-trip price

Cheap St. Louis to Portland, Maine (STL to PWM) flight deals and tips

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

Best Price Found	$133
Fastest flight time	4h 27m
Direct flights	None

The best one-way flight to Portland, Maine from St. Louis in the past 72 hours is $133. The best round-trip flight deal from St. Louis to Portland, Maine found on momondo in the last 72 hours is $282.

The fastest flight from St. Louis to Portland, Maine takes 4h 27m

There are no direct flights from St. Louis to Portland, Maine. There are no popular flight routes from St. Louis to Portland, Maine.

Search flight deals

Frequently asked questions about flying from St. Louis to Portland, Maine

How far is Lambert-St Louis to Portland by plane?
Portland is 1090.4 mi away from Lambert-St Louis. In terms of flight time, this usually takes a little over 4h 27m.
When did momondo last update prices for flights from Lambert-St Louis Airport to Portland Airport?
Prices for flights from Lambert-St Louis Airport to Portland Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Lambert-St Louis Airport to Portland Airport?
The number of operators available for flights from Lambert-St Louis Airport to Portland Airport is 4 as of September 2026.
How old do you have to be to fly from Lambert-St Louis Airport to Portland Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Lambert-St Louis Airport to Portland Airport.
What documentation or ID do you need to fly to Portland Airport?
The travel and health documents you'll need for your trip to Portland Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Portland Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.
What is the most popular airline from St. Louis to Portland, Maine?
Based on momondo bookings for flights between St. Louis and Portland, Maine, the leading airline is American Airlines, making up 52% of the total bookings. Other popular airlines include Delta with 25%, United Airlines with 12%, and Southwest with 11%.

Best airlines flying from St. Louis to Portland, Maine

Compare and see reviews for airlines that fly from St. Louis to Portland, Maine with momondo

Airline	Rating	Free Cancellation	Price
Delta	PriceFrom $298	Free Cancellation	Rating 7.8 8,590 reviews	Search Delta flights
American Airlines	PriceFrom $298	Free Cancellation	Rating 7.0 12,072 reviews	Search American Airlines flights
United Airlines	PriceFrom $327	Free Cancellation	Rating 7.4 10,220 reviews	Search United Airlines flights
Southwest	PriceFrom $366	Free Cancellation	Rating 8.0 4,193 reviews	Search Southwest flights

North Conway

Jackson

Boothbay Harbor

Brunswick

Lewiston

Freeport

Auburn

Conway

Bartlett

Gorham

Bath

Windham

Intervale

Oxford

Georgetown

Falmouth

Tamworth

Why use momondo?

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

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from St. Louis to Portland. momondo saves you time and could save you money on your trip.

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

All flight searches from St. Louis to Portland on momondo can be filtered to show those which offer flexible booking policies.

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

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to Portland.

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

Price alerts on flights to Portland from St. Louis are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

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Cheap flights from St. Louis to Portland from $133

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Portland departing on 10/19. 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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Southwest flights from St. Louis to Portland, Maine

Our best Southwest deals on St. Louis to Portland, Maine flight tickets

Delta flights from St. Louis to Portland, Maine

Our best Delta deals on St. Louis to Portland, Maine flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from St. Louis to Portland, Maine that are best for you.

See travel insights to Portland from

How to get the cheapest flight ticket from St. Louis to Portland, Maine

What is the typical price of a round-trip flight between St. Louis and Portland, Maine?

What is the cheapest month to fly to Portland, Maine?

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

Can stopping save me money on St. Louis to Portland, Maine flights?

How have St. Louis to Portland, Maine flight prices changed over time?

What is the cheapest airline that flies from Lambert-St Louis to Portland?

What airlines fly to Portland, Maine?

When to book flights from St. Louis to Portland, Maine

Cheap St. Louis to Portland, Maine (STL to PWM) flight deals and tips

Best Price Found

Fastest flight time

Direct flights

Frequently asked questions about flying from St. Louis to Portland, Maine

Best airlines flying from St. Louis to Portland, Maine

Compare and see reviews for airlines that fly from St. Louis to Portland, Maine with momondo

Traveling to a place near Portland?

Why use momondo?

An easier way to manage your Portland, Maine trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to the United States

Airports servicing Maine

Fly your favorite airline to Portland

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Cabin classes currently available on flights to Portland

List of cabin classes available on flights landing in Portland. Availability may vary depending on flight origin and airline.

Popular cities in the United States

Popular flights according to clicks in the last 7 days on momondo

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According to popular flight searches on momondo this year

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