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Cheap flights from Portland to St. Louis from $106

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Portland to St. Louis departing on 9/8. 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
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Portland to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
5:56 pm - 7:13 pm-
23h 17m
Frontier Logo
12:17 pm - 11:36 am-
25h 19m
$240Frontier
Wed, Sep 2 - Wed, Sep 9
Frontier Logo
9:03 pm - 10:39 pm-
23h 36m
Frontier Logo
5:32 pm - 8:08 pm-
28h 36m
$240Frontier
Fri, Nov 6 - Sun, Nov 8
Alaska Airlines Logo
11:16 am - 5:10 pm-
3h 54mnonstop
Alaska Airlines Logo
6:08 pm - 8:20 pm-
4h 12mnonstop
$297Alaska Airlines
Wed, Sep 23 - Wed, Sep 30
Alaska Airlines Logo
11:16 am - 5:10 pm-
3h 54mnonstop
Alaska Airlines Logo
6:08 pm - 8:20 pm-
4h 12mnonstop
$297Alaska Airlines
Tue, Sep 1 - Tue, Sep 8
Southwest Logo
9:45 am - 3:30 pm-
3h 45mnonstop
Southwest Logo
8:30 am - 10:40 am-
4h 10mnonstop
$297Southwest
Sat, Aug 29 - Sat, Sep 5
Southwest Logo
9:00 am - 6:25 pm-
7h 25m
Southwest Logo
8:30 am - 10:40 am-
4h 10mnonstop
$307Southwest
Sat, Aug 29 - Sat, Sep 5
Delta Logo
7:33 pm - 10:39 am-
13h 06m
Delta Logo
6:20 am - 5:04 pm-
12h 44m
$313Delta
Fri, Nov 13 - Sun, Nov 15
Delta Logo
7:33 pm - 9:19 am-
11h 46m
Delta Logo
7:10 am - 6:53 pm-
13h 43m
$313Delta
Sun, Nov 22 - Thu, Nov 26
American Airlines Logo
5:00 am - 2:04 pm-
7h 04m
American Airlines Logo
5:00 am - 12:33 pm-
9h 33m
$317American Airlines
Wed, Nov 4 - Wed, Nov 11
American Airlines Logo
11:08 pm - 10:18 am-
9h 10m
American Airlines Logo
8:00 am - 1:35 pm-
7h 35m
$317American Airlines
Wed, Sep 16 - Tue, Sep 22

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United Airlines flights from Portland to St. Louis

Our best United Airlines deals on Portland to St. Louis flight tickets
United Airlines
Oct 24
PDX4:07 pmPortland
5h 37m
1 stop
STL11:44 pmLambert-St Louis
Oct 31
STL6:00 amLambert-St Louis
9h 25m
2 stops
PDX1:25 pmPortland
$322
United Airlines
Aug 18
PDX11:02 pmPortland
7h 37m
1 stop
STL8:39 amLambert-St Louis
Aug 19
STL1:36 pmLambert-St Louis
6h 13m
1 stop
PDX5:49 pmPortland
$402
United Airlines
Aug 15
PDX11:17 pmPortland
9h 59m
1 stop
STL11:16 amLambert-St Louis
Aug 18
STL12:59 pmLambert-St Louis
10h 06m
2 stops
PDX9:05 pmPortland
$512

Frontier flights from Portland to St. Louis

Our best Frontier deals on Portland to St. Louis flight tickets
Frontier
Sep 11
PDX12:39 pmPortland
20h 53m
1 stop
STL11:32 amLambert-St Louis
Sep 13
STL1:02 pmLambert-St Louis
24h 41m
1 stop
PDX11:43 amPortland
$240
Frontier
Oct 22
PDX12:34 pmPortland
28h 41m
1 stop
STL7:15 pmLambert-St Louis
Oct 29
STL8:10 pmLambert-St Louis
22h 25m
1 stop
PDX4:35 pmPortland
$247
Frontier
Sep 17
PDX12:38 pmPortland
28h 39m
1 stop
STL7:17 pmLambert-St Louis
Sep 20
STL8:10 pmLambert-St Louis
17h 33m
1 stop
PDX11:43 amPortland
$252

momondo 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, momondo users made 832,500 searches. Data last updated August 4, 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

Price

Cheapest round-trip

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Wed 9/2

5:56 pm-7:13 pm

1 stop23h 17m

Lambert-St Louis

Wed 9/9

12:17 pm-11:36 am

1 stop25h 19m

$240

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Fri 11/6

9:03 pm-10:39 pm

1 stop23h 36m

Lambert-St Louis

Sun 11/8

5:32 pm-8:08 pm

1 stop28h 36m

$240

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Wed 9/23

11:16 am-5:10 pm

Nonstop3h 54m

Lambert-St Louis

Wed 9/30

6:08 pm-8:20 pm

Nonstop4h 12m

$297

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Tue 9/1

11:16 am-5:10 pm

Nonstop3h 54m

Lambert-St Louis

Tue 9/8

6:08 pm-8:20 pm

Nonstop4h 12m

$297
Quickest round-trip

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sat 8/29

9:45 am-3:30 pm

Nonstop3h 45m

Lambert-St Louis

Sat 9/5

8:30 am-10:40 am

Nonstop4h 10m

$297

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sat 8/29

9:00 am-6:25 pm

1 stop7h 25m

Lambert-St Louis

Sat 9/5

8:30 am-10:40 am

Nonstop4h 10m

$307

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Fri 11/13

7:33 pm-10:39 am

2 stops13h 06m

Lambert-St Louis

Sun 11/15

6:20 am-5:04 pm

2 stops12h 44m

$313

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sun 11/22

7:33 pm-9:19 am

2 stops11h 46m

Lambert-St Louis

Thu 11/26

7:10 am-6:53 pm

2 stops13h 43m

$313

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Wed 11/4

5:00 am-2:04 pm

1 stop7h 04m

Lambert-St Louis

Wed 11/11

5:00 am-12:33 pm

1 stop9h 33m

$317

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Wed 9/16

11:08 pm-10:18 am

1 stop9h 10m

Lambert-St Louis

Tue 9/22

8:00 am-1:35 pm

1 stop7h 35m

$317

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to St. Louis from

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

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 typical price of a round-trip flight between Portland and St. Louis?

Prices are currently low for flights on this route.

Typical prices usually range from $318 to $457.
The lowest price recently found on this route was $240.

What is the cheapest month to fly to St. Louis?

In general, November is the cheapest month to fly from Portland to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $300. The month of May is another great option to travel to St. Louis, with average flight prices from Portland averaging around $318.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Tuesday when prices can be found for as low as $337. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $451. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest Portland to Lambert-St Louis flight route?

Fly from Portland to Lambert-St Louis for the best Portland - Lambert-St Louis flight prices

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

You are more likely to see cheaper flights to St. Louis from Portland when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $370 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Portland for as low as $240 on momondo.

What cabin class options are available on Portland to St. Louis flights?

There are 3 cabin classes available to choose from on Portland to St. Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

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

No. A direct flight is the cheapest option for a flight between Portland to St. Louis.

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

As of August 2026, prices for Portland to St. Louis flights are approximately 34% more expensive when compared to flights at the same time last year.

When to book flights from Portland to St. Louis

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

Cheap Portland to St. Louis (PDX to STL) flight deals and tips

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

Best Price Found

$218

Fastest flight time

3h 48m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Portland in the past 72 hours is $218. The best round-trip flight deal from Portland to St. Louis found on momondo in the last 72 hours is $337.
The fastest flight from Portland to St. Louis takes 3h 48m
Direct flights go from Portland to St. Louis every day.
There is 1 airport in St. Louis. From Portland there are direct flights to Lambert-St Louis (STL).
Search flight deals

Frequently asked questions about flying from Portland to St. Louis

  • How far is Portland to Lambert-St Louis by plane?

    A flight from Portland to Lambert-St Louis will travel around 1718.1 mi. A reasonable flight in good conditions will take 3h 48m.

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

    Prices for flights from Portland Airport to Lambert-St Louis Airport are updated daily.

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

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

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Portland Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents required for your trip to Lambert-St Louis Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Lambert-St Louis Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular plane model from Portland to St. Louis?

  • What is the most popular airline from Portland to St. Louis?

Best airlines flying from Portland to St. Louis

Compare and see reviews for airlines that fly from Portland to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $75Free CancellationRating
5.6
2,738 reviews
Search Frontier flights
DeltaPriceFrom $177Free CancellationRating
7.8
8,483 reviews
Search Delta flights
American AirlinesPriceFrom $208Free CancellationRating
7.1
11,851 reviews
Search American Airlines flights
Alaska AirlinesPriceFrom $213Free CancellationRating
7.9
12,762 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $248Free CancellationRating
8.0
4,222 reviews
Search Southwest flights
United AirlinesPriceFrom $248Free CancellationRating
7.4
10,060 reviews
Search United Airlines flights

  • Alaska Airlines Flights From Portland to St. Louis

    Alaska Airlines is one of the most popular airlines flying from Portland to St. Louis, operating 6 flights/week on average for this route. A good Alaska Airlines flight deal for Portland to St. Louis starts from $213 round-trip, up to an average price of $387. Our users have rated Alaska Airlines at 7.9/10.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Fairview Heights
Hermann
St. Peters
Maryland Heights
Florissant
Collinsville
Alton
O'Fallon
Clayton
Farmington
Fenton
Wentzville
Festus
Eureka
Edwardsville
Litchfield
Grafton
Shrewsbury

Why use momondo?

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

It is quick and easy to find Portland to St. Louis flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to St. Louis that suits you.

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

momondo does allow users to show only those flights to St. Louis from Portland which offer a flexible booking policy as well as other useful filters and features.

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

Once you have performed a search for Portland to St. Louis flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

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

Of course. momondo tracks the price of Portland to St. Louis flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

An easier way to manage your St. Louis trip

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