Latest deals
Insights
When to book
FAQs
Reviews
Price Alerts

Cheap flights from St. Louis to Portland from $168

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 4/20. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from St. Louis to Portland

Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
5:21 pm - 12:13 am
STL
-
PWM
5h 52m
1 stop
American Airlines Logo
5:51 pm - 10:19 pm
PWM
-
STL
5h 28m
1 stop
$317American Airlines
Tue, Apr 28 - Thu, May 7
United Airlines Logo
8:30 am - 2:23 pm
STL
-
PWM
4h 53m
1 stop
United Airlines Logo
4:15 pm - 9:40 pm
PWM
-
STL
6h 25m
1 stop
$339United Airlines
Mon, Feb 16 - Fri, Feb 20
United Airlines Logo
6:25 am - 2:23 pm
STL
-
PWM
6h 58m
2 stops
United Airlines Logo
4:15 pm - 9:40 pm
PWM
-
STL
6h 25m
1 stop
$344United Airlines
Mon, Feb 16 - Fri, Feb 20
United Airlines Logo
6:25 am - 2:23 pm
STL
-
PWM
6h 58m
2 stops
United Airlines Logo
2:10 pm - 9:40 pm
PWM
-
STL
8h 30m
2 stops
$349United Airlines
Mon, Feb 16 - Fri, Feb 20
United Airlines Logo
7:45 am - 2:14 pm
STL
-
PWM
5h 29m
1 stop
United Airlines Logo
4:45 pm - 9:08 pm
PWM
-
STL
5h 23m
1 stop
$353United Airlines
Tue, May 5 - Fri, May 8
Delta Logo
1:02 pm - 12:46 am
STL
-
PWM
10h 44m
2 stops
Delta Logo
12:52 pm - 5:16 pm
PWM
-
STL
5h 24m
1 stop
$358Delta
Tue, May 5 - Fri, May 8
Delta Logo
6:40 am - 11:57 am
STL
-
PWM
4h 17m
1 stop
Delta Logo
12:52 pm - 5:16 pm
PWM
-
STL
5h 24m
1 stop
$371Delta
Sat, May 16 - Thu, May 21
United Airlines Logo
10:00 am - 7:04 pm
STL
-
PWM
8h 04m
2 stops
United Airlines Logo
4:45 pm - 10:59 pm
PWM
-
STL
7h 14m
1 stop
$376United Airlines
Tue, May 5 - Fri, May 8
Southwest Logo
1:45 pm - 10:20 pm
STL
-
PWM
7h 35m
2 stops
Southwest Logo
2:50 pm - 10:55 pm
PWM
-
STL
9h 05m
2 stops
$403Southwest
Tue, May 5 - Fri, May 8
Delta Logo
6:20 am - 3:57 pm
STL
-
PWM
8h 37m
2 stops
Delta Logo
12:52 pm - 5:16 pm
PWM
-
STL
5h 24m
1 stop
$404Delta
Tue, Apr 28 - Thu, May 7

Southwest flights from St. Louis to Portland, Maine

Our best Southwest deals on St. Louis to Portland, Maine flight tickets
Southwest
May 5
STL1:45 pmLambert-St Louis
7h 35m
2 stops
PWM10:20 pmPortland
May 8
PWM2:50 pmPortland
9h 05m
2 stops
STL10:55 pmLambert-St Louis
$403
Southwest
Mar 11
STL2:25 pmLambert-St Louis
7h 40m
2 stops
PWM11:05 pmPortland
Mar 17
PWM12:30 pmPortland
8h 25m
2 stops
STL7:55 pmLambert-St Louis
$417
Southwest
Mar 27
STL4:45 pmLambert-St Louis
6h 20m
1 stop
PWM12:05 amPortland
Mar 29
PWM5:30 pmPortland
7h 45m
2 stops
STL12:15 amLambert-St Louis
$432

Delta flights from St. Louis to Portland, Maine

Our best Delta deals on St. Louis to Portland, Maine flight tickets
Delta
May 5
STL1:02 pmLambert-St Louis
10h 44m
2 stops
PWM12:46 amPortland
May 8
PWM12:52 pmPortland
5h 24m
1 stop
STL5:16 pmLambert-St Louis
$358
Delta
May 16
STL6:40 amLambert-St Louis
4h 17m
1 stop
PWM11:57 amPortland
May 21
PWM12:52 pmPortland
5h 24m
1 stop
STL5:16 pmLambert-St Louis
$371
Delta
Apr 28
STL6:20 amLambert-St Louis
8h 37m
2 stops
PWM3:57 pmPortland
May 7
PWM12:52 pmPortland
5h 24m
1 stop
STL5:16 pmLambert-St Louis
$404

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Portland, Maine 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, momondo users made 832,500 searches. Data last updated February 5, 2026.
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

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Tue 4/28

5:21 pm-12:13 am

1 stop5h 52m

Portland

Thu 5/7

5:51 pm-10:19 pm

1 stop5h 28m

$317

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Mon 2/16

8:30 am-2:23 pm

1 stop4h 53m

Portland

Fri 2/20

4:15 pm-9:40 pm

1 stop6h 25m

$339

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Mon 2/16

6:25 am-2:23 pm

2 stops6h 58m

Portland

Fri 2/20

4:15 pm-9:40 pm

1 stop6h 25m

$344

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Mon 2/16

6:25 am-2:23 pm

2 stops6h 58m

Portland

Fri 2/20

2:10 pm-9:40 pm

2 stops8h 30m

$349

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Tue 5/5

7:45 am-2:14 pm

1 stop5h 29m

Portland

Fri 5/8

4:45 pm-9:08 pm

1 stop5h 23m

$353

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Tue 5/5

1:02 pm-12:46 am

2 stops10h 44m

Portland

Fri 5/8

12:52 pm-5:16 pm

1 stop5h 24m

$358

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Sat 5/16

6:40 am-11:57 am

1 stop4h 17m

Portland

Thu 5/21

12:52 pm-5:16 pm

1 stop5h 24m

$371

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Tue 5/5

10:00 am-7:04 pm

2 stops8h 04m

Portland

Fri 5/8

4:45 pm-10:59 pm

1 stop7h 14m

$376

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Tue 5/5

1:45 pm-10:20 pm

2 stops7h 35m

Portland

Fri 5/8

2:50 pm-10:55 pm

2 stops9h 05m

$403

St. LouisPortland

STL - PWM

STLPWM

Lambert-St Louis

Tue 4/28

6:20 am-3:57 pm

2 stops8h 37m

Portland

Thu 5/7

12:52 pm-5:16 pm

1 stop5h 24m

$404

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

See travel insights to Portland from

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

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 $386, 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 December is also cheap. Prices for this month can be found on momondo for an average of $386.

How far in advance should I book a flight 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 $440 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 $323 on momondo.

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

As of February 2026, prices for St. Louis to Portland, Maine flights are approximately 12% 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

Fastest flight time

4h 17m

Direct flights

None
The fastest flight from St. Louis to Portland, Maine takes 4h 17m
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

  • 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 17m.

  • 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?

  • 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?

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
United AirlinesPriceFrom $212Free CancellationRating
7.4
9,240 reviews
Search United Airlines flights
DeltaPriceFrom $272Free CancellationRating
7.9
8,151 reviews
Search Delta flights
SouthwestPriceFrom $284Free CancellationRating
8.0
4,275 reviews
Search Southwest flights
American AirlinesPriceFrom $284Free CancellationRating
7.2
11,237 reviews
Search American Airlines flights

Traveling to a place near Portland?

Book flights to Portland if you plan to visit one of these locations
North Conway
Boothbay Harbor
Jackson
Conway
Freeport
Lewiston
Brunswick
Bartlett
Gorham
Auburn
Windham
Intervale
Bath
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.

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.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Sat 3/7
Sat 3/14
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States