$202+ Cheap flights from Portland, ME to St. Louis (PWM - STL)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/25. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — STL
Oct 8 — Oct 151
Round-trip
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.Cheap flight deals from Portland to St. Louis
Cheapest
Best
Last-minute
One-way
Cheapest flights from Portland to St. LouisExplore 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 September 8, 2026.
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 September 8, 2026.
This American Airlines deal was found by Cheapflights users on 9/3. 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 10/75:30 am -
1 stop6h 11m
Fri 10/95:40 pm -
1 stop4h 56m
Deal found 9/3![American Airlines logo]()
$362
This Southwest deal was found by Cheapflights users on 9/7. 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 10/15:20 am -
1 stop6h 10m
Sat 10/33:40 pm -
1 stop5h 30m
Deal found 9/7![Southwest logo]()
$381
This American Airlines deal was found by Cheapflights users on 9/7. 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.
Sun 11/15:15 am -
1 stop5h 40m
Thu 11/55:00 am -
1 stop5h 53m
Deal found 9/7![American Airlines logo]()
$388
This Southwest deal was found by Cheapflights users on 9/7. 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.
Mon 11/2311:10 am -
2 stops8h 30m
Thu 12/36:20 am -
2 stops7h 25m
Deal found 9/7![Southwest logo]()
$391
This American Airlines deal was found by Cheapflights users on 9/3. 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.
Sun 10/45:15 am -
1 stop6h 14m
Tue 10/65:50 pm -
1 stop4h 46m
Deal found 9/3![American Airlines logo]()
$396
This Southwest deal was found by Cheapflights users on 9/7. 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 10/15:20 am -
1 stop6h 10m
Fri 10/25:40 pm -
1 stop5h 15m
Deal found 9/7![Southwest logo]()
$398
This United Airlines deal was found by Cheapflights users on 9/4. 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.
Thu 10/86:00 am -
1 stop6h 22m
Thu 10/158:00 am -
1 stop5h 38m
Deal found 9/4![United Airlines logo]()
$403
This United Airlines deal was found by Cheapflights users on 9/5. 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.
Wed 10/217:58 am -
1 stop5h 15m
Sat 10/246:00 am -
2 stops7h 38m
Deal found 9/5![United Airlines logo]()
$408
This American Airlines deal was found by Cheapflights users on 9/4. 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.
Fri 10/97:24 pm -
1 stop5h 35m
Sat 10/105:40 pm -
1 stop4h 56m
Deal found 9/4![American Airlines logo]()
$410
This American Airlines deal was found by Cheapflights users on 9/3. 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.
Fri 10/236:00 am -
1 stop7h 46m
Sun 10/255:00 am -
1 stop6h 31m
Deal found 9/3![American Airlines logo]()
$411
This Southwest deal was found by Cheapflights users on 9/4. 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.
Fri 11/61:40 pm -
2 stops8h 20m
Mon 11/94:40 pm -
2 stops6h 10m
Deal found 9/4![Southwest logo]()
$413
Best flights from Portland to St. LouisDiscover carefully curated flight deals from Portland to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 8, 2026.
Discover carefully curated flight deals from Portland to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 8, 2026.
This United Airlines deal was found by Cheapflights users on 9/4. 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.
Thu 10/86:00 am -
1 stop6h 22m
Thu 10/158:00 am -
1 stop5h 38m
Deal found 9/4![United Airlines logo]()
$403
This Southwest deal was found by Cheapflights users on 9/4. 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.
Tue 11/173:25 pm -
2 stops7h 30m
Thu 11/196:35 am -
1 stop4h 35m
Deal found 9/4![Southwest logo]()
$408
This Southwest deal was found by Cheapflights users on 9/4. 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.
Fri 11/61:40 pm -
2 stops8h 20m
Mon 11/95:10 pm -
1 stop5h 40m
Deal found 9/4![Southwest logo]()
$408
This United Airlines deal was found by Cheapflights users on 9/5. 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.
Wed 10/217:58 am -
1 stop5h 15m
Sat 10/246:00 am -
2 stops7h 38m
Deal found 9/5![United Airlines logo]()
$408
This Southwest deal was found by Cheapflights users on 9/6. 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.
Tue 10/205:40 am -
1 stop6h 55m
Thu 10/222:30 pm -
2 stops8h 25m
Deal found 9/6![Southwest logo]()
$418
This United Airlines deal was found by Cheapflights users on 9/7. 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 2/23:15 pm -
1 stop7h 38m
Wed 2/37:30 am -
1 stop6h 12m
Deal found 9/7![United Airlines logo]()
$429
This Southwest deal was found by Cheapflights users on 9/5. 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 10/215:40 am -
2 stops10h 20m
Sat 10/2412:55 pm -
2 stops8h 20m
Deal found 9/5![Southwest logo]()
$419
This Southwest deal was found by Cheapflights users on 9/3. 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 10/75:40 am -
1 stop6h 55m
Fri 10/97:50 pm -
2 stops12h 55m
Deal found 9/3![Southwest logo]()
$439
This United Airlines deal was found by Cheapflights users on 9/3. 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.
Sun 10/46:00 am -
1 stop5h 48m
Tue 10/68:00 am -
2 stops10h 24m
Deal found 9/3![United Airlines logo]()
$483
This United Airlines deal was found by Cheapflights users on 9/7. 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.
Sun 11/15:50 am -
2 stops10h 53m
Thu 11/56:00 am -
1 stop7h 16m
Deal found 9/7![United Airlines logo]()
$493
Last-minute flights from Portland to St. LouisDiscover last-minute flight deals from Portland to St. Louis. Data last updated September 8, 2026 and is based on user searches.
Discover last-minute flight deals from Portland to St. Louis. Data last updated September 8, 2026 and is based on user searches.
This American Airlines deal was found by Cheapflights users on 9/4. 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.
Fri 10/25:38 pm -
1 stop7h 49m
Sun 10/45:10 pm -
1 stop5h 37m
Deal found 9/4![American Airlines logo]()
$420
This American Airlines deal was found by Cheapflights users on 9/3. 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.
Sun 10/45:15 am -
1 stop6h 14m
Tue 10/65:50 pm -
1 stop4h 46m
Deal found 9/3![American Airlines logo]()
$396
This American Airlines deal was found by Cheapflights users on 9/3. 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 10/75:30 am -
1 stop6h 11m
Fri 10/95:40 pm -
1 stop4h 56m
Deal found 9/3![American Airlines logo]()
$362
This United Airlines deal was found by Cheapflights users on 9/4. 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.
Thu 10/86:00 am -
1 stop6h 22m
Thu 10/158:00 am -
1 stop5h 38m
Deal found 9/4![United Airlines logo]()
$403
This American Airlines deal was found by Cheapflights users on 9/4. 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.
Fri 10/97:24 pm -
1 stop5h 35m
Sat 10/105:40 pm -
1 stop4h 56m
Deal found 9/4![American Airlines logo]()
$410
This Kiwi.com deal was found by Cheapflights users on 9/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/197:00 am -
2 stops11h 40m
Thu 10/224:30 pm -
1 stop15h 38m
Deal found 9/6![Multiple Airlines logo]()
$423
This Southwest deal was found by Cheapflights users on 9/6. 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.
Tue 10/205:40 am -
1 stop6h 55m
Thu 10/222:30 pm -
2 stops8h 25m
Deal found 9/6![Southwest logo]()
$418
This United Airlines deal was found by Cheapflights users on 9/5. 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.
Wed 10/217:58 am -
1 stop5h 15m
Sat 10/246:00 am -
2 stops7h 38m
Deal found 9/5![United Airlines logo]()
$408
This Southwest deal was found by Cheapflights users on 9/5. 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 10/215:40 am -
2 stops10h 20m
Sat 10/2412:55 pm -
2 stops8h 20m
Deal found 9/5![Southwest logo]()
$419
This American Airlines deal was found by Cheapflights users on 9/3. 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.
Fri 10/236:00 am -
1 stop7h 46m
Sun 10/255:00 am -
1 stop6h 31m
Deal found 9/3![American Airlines logo]()
$411
One-way flights from Portland to St. LouisSearch for one-way flight options from Portland to St. Louis. Find affordable one-way fares based on user searches. Data last updated September 8, 2026.
Search for one-way flight options from Portland to St. Louis. Find affordable one-way fares based on user searches. Data last updated September 8, 2026.
This American Airlines deal was found by Cheapflights users on 9/7. 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.
Fri 12/255:25 am -
1 stop7h 38m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![American Airlines logo]()
$202
This Southwest deal was found by Cheapflights users on 9/7. 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.
Tue 11/241:25 pm -
1 stop11h 30m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![Southwest logo]()
$224
This American Airlines deal was found by Cheapflights users on 9/4. 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.
Sun 10/45:15 am -
1 stop6h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/4![American Airlines logo]()
$225
This Kiwi.com deal was found by Cheapflights users on 9/4. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/197:00 am -
2 stops11h 40m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/4![Multiple Airlines logo]()
$242
This United Airlines deal was found by Cheapflights users on 9/7. 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 12/256:00 am -
2 stops9h 18m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![United Airlines logo]()
$252
This American Airlines deal was found by Cheapflights users on 9/3. 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.
Thu 9/175:38 pm -
1 stop7h 49m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/3![American Airlines logo]()
$259
This American Airlines deal was found by Cheapflights users on 9/4. 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.
Mon 10/197:24 pm -
1 stop5h 35m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/4![American Airlines logo]()
$262
This United Airlines deal was found by Cheapflights users on 9/3. 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.
Thu 9/175:15 am -
2 stops7h 42m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/3![United Airlines logo]()
$264
This United Airlines deal was found by Cheapflights users on 9/7. 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.
Sun 10/45:15 am -
2 stops8h 00m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![United Airlines logo]()
$289
Find 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 September 8, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $362 (American Airlines) |
One-way from | $202 (American Airlines) |
Popular in | April |
Cheapest in | March |
Average price | $426 |
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 7,457,451 searches. Data last updated September 8, 2026.
Use the filters below to find and compare flights from Portland to St. Louis that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Tue 11/24
1:25 pm-11:55 pm
1 stop11h 30m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$224
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Sun 10/4
5:15 am-10:29 am
1 stop6h 14m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$225
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Mon 10/19
7:00 am-5:40 pm
2 stops11h 40m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$242
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Fri 12/25
6:00 am-2:18 pm
2 stops9h 18m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$252
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Sun 9/20
5:15 am-10:29 am
1 stop6h 14m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$259
Quickest round-trip
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Mon 10/19
7:24 pm-11:59 pm
1 stop5h 35m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$262
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Thu 9/17
5:15 am-11:57 am
2 stops7h 42m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$264
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Sun 9/20
5:15 am-12:02 pm
2 stops7h 47m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$264
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Thu 10/8
6:00 am-11:22 am
1 stop6h 22m
Lambert-St Louis
Thu 10/15
8:00 am-2:38 pm
1 stop5h 38m
$403
PortlandSt. Louis
PWM Portland - STL Lambert-St Louis
PWMSTL
Portland
Tue 11/17
3:25 pm-9:55 pm
2 stops7h 30m
Lambert-St Louis
Thu 11/19
6:35 am-12:10 pm
1 stop4h 35m
$408
Showing 1-10 of 18 resultsSorted by cheapest first
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 September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on Portland, Maine-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Portland, Maine-St. Louis flight deals on Cheapflights vs. FlightHub >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 FlightHub the most. FlightHub 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.
PWM-STL
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, March is the cheapest month in which you can book a flight from Portland, Maine to St. Louis (average of $334). Flying from Portland, Maine to St. Louis in April is currently the most expensive (average of $568). 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.
How much does it cost to fly round-trip from Portland, Maine to St. Louis?
Airfare is typical for this route at the moment.
Portland, Maine to St. Louis flights typically cost between $288 and $721 in October.The cheapest round-trip price found within the last 5 days was $362 on American Airlines (Oct 7-Oct 9).
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 September 8, 2026.
Get a feel of what it's like to fly with Southwest,Delta, andUnited 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.
Comfort
8.0
Boarding
8.1
Food
7.0
Crew
8.6
Overall
8.0
Entertainment
7.5
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Comfort
8.0
Boarding
8.1
Food
7.0
Crew
8.6
Overall
8.0
Entertainment
7.5
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Comfort
8.0
Boarding
8.1
Food
7.0
Crew
8.6
Overall
8.0
Entertainment
7.5
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Comfort
8.0
Boarding
8.1
Food
7.0
Crew
8.6
Overall
8.0
Entertainment
7.5
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Comfort
8.0
Boarding
8.1
Food
7.0
Crew
8.6
Overall
8.0
Entertainment
7.5
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
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.
Traveling to a place near St. Louis?
Book flights to St. Louis if you plan to visit one of these locationsEdwardsville
Fairview Heights
O'Fallon
Fenton
Swansea
Eureka
Maryland Heights
Collinsville
Wentzville
Glencoe
Chesterfield
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.
Alternative routes
Complete your trip
Flights by cabin class
Other flight options
Other flights from Portland
Popular flights
St. Louis flight routes
Alternative routes for Portland to St. Louis
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to St. Louis by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Portland to St. Louis by cabin class
Find flights from Portland to St. Louis, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Portland and St. Louis flights
Browse other Portland and St. Louis flight options. Last updated on September 8, 2026.
Other flights from Portland
Browse through other flights departing from Portland. Flights are based on user searches made on Cheapflights and were last updated on September 8, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Other flights to St. Louis
Explore flights to St. Louis departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 8, 2026.
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 7,457,451 searches. Data last updated September 8, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$268 | Average$407 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$316 | Average$465 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$348 | Average$576 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$361 | Average$526 | FlexibilityNo cancel fee | On-time69% |