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Cheap flights from Portland to St. Louis from $85

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 2/20. 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

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Find the cheapest flights from Portland to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
11:40 pm - 8:55 am
PDX
-
STL
7h 15m
1 stop
American Airlines Logo
6:00 am - 10:58 am
STL
-
PDX
6h 58m
1 stop
$249American Airlines
Mon, Feb 23 - Wed, Feb 25
Alaska Airlines Logo
11:25 am - 5:13 pm
PDX
-
STL
3h 48mnonstop
Alaska Airlines Logo
6:20 pm - 8:30 pm
STL
-
PDX
4h 10mnonstop
$264Alaska Airlines
Fri, Jun 12 - Fri, Jun 12
American Airlines Logo
11:40 pm - 8:57 am
PDX
-
STL
7h 17m
1 stop
American Airlines Logo
2:12 pm - 8:59 pm
STL
-
PDX
8h 47m
1 stop
$273American Airlines
Thu, Apr 16 - Sat, Apr 18
Delta Logo
1:55 pm - 12:21 am
PDX
-
STL
8h 26m
2 stops
Delta Logo
6:12 pm - 11:54 pm
STL
-
PDX
7h 42m
1 stop
$281Delta
Wed, Apr 1 - Mon, Apr 6
Delta Logo
6:05 am - 2:24 pm
PDX
-
STL
6h 19m
1 stop
Delta Logo
6:12 pm - 11:54 pm
STL
-
PDX
7h 42m
1 stop
$284Delta
Sat, Mar 14 - Wed, Mar 18
Alaska Airlines Logo
11:59 am - 11:59 pm
PDX
-
STL
10h 00m
1 stop
Alaska Airlines Logo
6:20 pm - 8:37 pm
STL
-
PDX
4h 17mnonstop
$288Alaska Airlines
Mon, May 4 - Mon, May 25
United Airlines Logo
12:59 pm - 10:00 pm
PDX
-
STL
7h 01m
1 stop
United Airlines Logo
6:00 pm - 11:14 pm
STL
-
PDX
7h 14m
1 stop
$293United Airlines
Sun, Feb 8 - Thu, Feb 19
Alaska Airlines Logo
12:00 pm - 11:57 pm
PDX
-
STL
9h 57m
1 stop
Alaska Airlines Logo
6:20 pm - 8:37 pm
STL
-
PDX
4h 17mnonstop
$294Alaska Airlines
Thu, May 21 - Wed, May 27
Delta Logo
11:35 am - 11:23 pm
PDX
-
STL
9h 48m
2 stops
Delta Logo
6:12 pm - 11:54 pm
STL
-
PDX
7h 42m
1 stop
$301Delta
Wed, Mar 4 - Mon, Mar 9
Delta Logo
1:32 pm - 12:22 am
PDX
-
STL
8h 50m
2 stops
Delta Logo
12:23 pm - 5:32 pm
STL
-
PDX
7h 09m
1 stop
$302Delta
Thu, Apr 16 - Sat, Apr 18

Delta flights from Portland to St. Louis

Our best Delta deals on Portland to St. Louis flight tickets
Delta
Apr 1
PDX1:55 pmPortland
8h 26m
2 stops
STL12:21 amLambert-St Louis
Apr 6
STL6:12 pmLambert-St Louis
7h 42m
1 stop
PDX11:54 pmPortland
$281
Delta
Mar 14
PDX6:05 amPortland
6h 19m
1 stop
STL2:24 pmLambert-St Louis
Mar 18
STL6:12 pmLambert-St Louis
7h 42m
1 stop
PDX11:54 pmPortland
$284
Delta
Mar 4
PDX11:35 amPortland
9h 48m
2 stops
STL11:23 pmLambert-St Louis
Mar 9
STL6:12 pmLambert-St Louis
7h 42m
1 stop
PDX11:54 pmPortland
$301

United Airlines flights from Portland to St. Louis

Our best United Airlines deals on Portland to St. Louis flight tickets
United Airlines
Feb 8
PDX12:59 pmPortland
7h 01m
1 stop
STL10:00 pmLambert-St Louis
Feb 19
STL6:00 pmLambert-St Louis
7h 14m
1 stop
PDX11:14 pmPortland
$293
United Airlines
Apr 16
PDX11:59 pmPortland
6h 36m
1 stop
STL8:35 amLambert-St Louis
Apr 17
STL6:05 pmLambert-St Louis
6h 49m
1 stop
PDX10:54 pmPortland
$314
United Airlines
Feb 6
PDX5:00 amPortland
6h 16m
1 stop
STL1:16 pmLambert-St Louis
Feb 8
STL6:00 amLambert-St Louis
8h 18m
1 stop
PDX12:18 pmPortland
$337

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 January 24, 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

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Mon 2/23

11:40 pm-8:55 am

1 stop7h 15m

Lambert-St Louis

Wed 2/25

6:00 am-10:58 am

1 stop6h 58m

$249

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Fri 6/12

11:25 am-5:13 pm

Nonstop3h 48m

Lambert-St Louis

Fri 6/12

6:20 pm-8:30 pm

Nonstop4h 10m

$264

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Thu 4/16

11:40 pm-8:57 am

1 stop7h 17m

Lambert-St Louis

Sat 4/18

2:12 pm-8:59 pm

1 stop8h 47m

$273

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Wed 4/1

1:55 pm-12:21 am

2 stops8h 26m

Lambert-St Louis

Mon 4/6

6:12 pm-11:54 pm

1 stop7h 42m

$281

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sat 3/14

6:05 am-2:24 pm

1 stop6h 19m

Lambert-St Louis

Wed 3/18

6:12 pm-11:54 pm

1 stop7h 42m

$284

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Mon 5/4

11:59 am-11:59 pm

1 stop10h 00m

Lambert-St Louis

Mon 5/25

6:20 pm-8:37 pm

Nonstop4h 17m

$288

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sun 2/8

12:59 pm-10:00 pm

1 stop7h 01m

Lambert-St Louis

Thu 2/19

6:00 pm-11:14 pm

1 stop7h 14m

$293

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Thu 5/21

12:00 pm-11:57 pm

1 stop9h 57m

Lambert-St Louis

Wed 5/27

6:20 pm-8:37 pm

Nonstop4h 17m

$294

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Wed 3/4

11:35 am-11:23 pm

2 stops9h 48m

Lambert-St Louis

Mon 3/9

6:12 pm-11:54 pm

1 stop7h 42m

$301

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Thu 4/16

1:32 pm-12:22 am

2 stops8h 50m

Lambert-St Louis

Sat 4/18

12:23 pm-5:32 pm

1 stop7h 09m

$302

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 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 September is another great option to travel to St. Louis, with average flight prices from Portland averaging around $317.

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 Saturday when prices can be found for as low as $548. 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 $621. 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 time of day to depart on your flight to St. Louis?

Flying to St. Louis from Portland in the morning is the least expensive time of day to depart. momondo users have found prices as low as $506 when looking at flights departing in the morning. At noon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $679 per ticket.

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 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 $369 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 $243 on momondo.

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

There is only 1 cabin class available to choose from on Portland to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

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

As of January 2026, prices for Portland to St. Louis flights are approximately 64% 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

$114

Fastest flight time

5h 19m

Direct flights

Mon, Tue, Fri, Sat and Sun

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Portland in the past 72 hours is $114. The best round-trip flight deal from Portland to St. Louis found on momondo in the last 72 hours is $242.
The fastest flight from Portland to St. Louis takes 5h 19m
Direct flights go from Portland to St. Louis on Monday, Tuesday, Friday, Saturday and Sunday. The only airline offering direct flights is Alaska Airlines.
There is 1 airport in St. Louis. From Portland there are direct flights to Lambert-St Louis (STL).
Search flight deals

  • 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 5h 19m.

  • 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 $139Free CancellationRating
5.7
3,058 reviews
Search Frontier flights
DeltaPriceFrom $186Free CancellationRating
7.9
8,110 reviews
Search Delta flights
American AirlinesPriceFrom $226Free CancellationRating
7.2
11,192 reviews
Search American Airlines flights
United AirlinesPriceFrom $226Free CancellationRating
7.4
9,194 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $242Free CancellationRating
8.0
11,785 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $248Free CancellationRating
8.0
4,268 reviews
Search Southwest flights

Traveling to a place near St. Louis?

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

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