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Cheap flights from Portland to St. Louis from $87

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 9/3. 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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0 bags

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Find the cheapest flights from Portland to St. Louis (PDX-STL)

Cheap round-trip flights

Delta Logo
12:40 am - 8:51 amPDX-STL
6h 11m1 stop
Delta Logo
12:14 pm - 5:27 pmSTL-PDX
7h 13m1 stop
$229Delta
Find Deal
Thu, Oct 23 - Tue, Oct 28
Frontier Logo
6:05 am - 9:06 amPDX-STL
25h 01m1 stop
Frontier Logo
7:55 pm - 12:12 amSTL-PDX
6h 17m1 stop
$230Frontier
Find Deal
Thu, Sep 18 - Sun, Sep 21
United Airlines Logo
5:00 am - 12:43 pmPDX-STL
5h 43m1 stop
United Airlines Logo
1:40 pm - 8:50 pmSTL-PDX
9h 10m2 stops
$234United Airlines
Find Deal
Sat, Sep 20 - Sat, Sep 27
Southwest Logo
6:40 am - 10:15 pmPDX-STL
13h 35m2 stops
Southwest Logo
5:35 am - 9:35 amSTL-PDX
6h 00m1 stop
$240Southwest
Find Deal
Tue, Sep 30 - Mon, Oct 6
Logo
7:15 am - 9:06 amPDX-STL
23h 51m1 stop
Logo
4:00 pm - 11:11 amSTL-PDX
21h 11m2 stops
$252
Find Deal
Sat, Sep 20 - Mon, Sep 29
American Airlines Logo
5:38 am - 3:09 pmPDX-STL
7h 31m1 stop
American Airlines Logo
3:59 pm - 9:27 pmSTL-PDX
7h 28m1 stop
$255American Airlines
Find Deal
Sat, Sep 13 - Sat, Sep 20
Southwest Logo
10:20 am - 11:05 pmPDX-STL
10h 45m2 stops
Southwest Logo
4:00 pm - 9:25 pmSTL-PDX
7h 25m1 stop
$259Southwest
Find Deal
Thu, Oct 30 - Tue, Nov 4
Logo
6:05 am - 9:06 amPDX-STL
25h 01m1 stop
Logo
6:20 am - 1:24 pmSTL-PDX
9h 04m1 stop
$260
Find Deal
Thu, Sep 11 - Sun, Sep 14
United Airlines Logo
5:00 am - 3:44 pmPDX-STL
8h 44m2 stops
United Airlines Logo
5:15 am - 9:29 amSTL-PDX
6h 14m1 stop
$270United Airlines
Find Deal
Sat, Sep 20 - Mon, Sep 29
American Airlines Logo
3:23 pm - 11:59 pmPDX-STL
6h 36m1 stop
American Airlines Logo
7:23 am - 2:33 pmSTL-PDX
9h 10m1 stop
$303American Airlines
Find Deal
Thu, Sep 11 - Sat, Sep 13

Delta flights from Portland to St. Louis

Our best Delta deals on Portland to St. Louis flight tickets
Delta
Oct 23
PDX12:40 amPortland
6h 11m
1 stop
STL8:51 amLambert-St Louis
Oct 28
STL12:14 pmLambert-St Louis
7h 13m
1 stop
PDX5:27 pmPortland
$229
Find similar
Delta
Oct 23
PDX12:40 amPortland
6h 11m
1 stop
STL8:51 amLambert-St Louis
Oct 26
STL6:00 amLambert-St Louis
8h 50m
1 stop
PDX12:50 pmPortland
$254
Find similar
Delta
Sep 26
PDX10:50 pmPortland
8h 43m
1 stop
STL9:33 amLambert-St Louis
Sep 30
STL2:15 pmLambert-St Louis
11h 37m
2 stops
PDX11:52 pmPortland
$271
Find similar

Frontier flights from Portland to St. Louis

Our best Frontier deals on Portland to St. Louis flight tickets
Frontier
Sep 18
PDX6:05 amPortland
25h 01m
1 stop
STL9:06 amLambert-St Louis
Sep 21
STL7:55 pmLambert-St Louis
6h 17m
1 stop
PDX12:12 amPortland
$230
Find similar
Frontier
Aug 31
PDX6:27 amPortland
24h 44m
1 stop
STL9:11 amLambert-St Louis
Sep 8
STL7:55 pmLambert-St Louis
6h 17m
1 stop
PDX12:12 amPortland
$249
Find similar
Frontier
Aug 31
PDX6:27 amPortland
24h 44m
1 stop
STL9:11 amLambert-St Louis
Sep 2
STL7:54 pmLambert-St Louis
28h 45m
1 stop
PDX10:39 pmPortland
$255
Find similar

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 25, 2025.
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

Thu 10/23

12:40 am-8:51 am

1 stop6h 11m

Lambert-St Louis

Tue 10/28

12:14 pm-5:27 pm

1 stop7h 13m

$229

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Thu 9/18

6:05 am-9:06 am

1 stop25h 01m

Lambert-St Louis

Sun 9/21

7:55 pm-12:12 am

1 stop6h 17m

$230

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sat 9/20

5:00 am-12:43 pm

1 stop5h 43m

Lambert-St Louis

Sat 9/27

1:40 pm-8:50 pm

2 stops9h 10m

$234

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Tue 9/30

6:40 am-10:15 pm

2 stops13h 35m

Lambert-St Louis

Mon 10/6

5:35 am-9:35 am

1 stop6h 00m

$240

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sat 9/20

7:15 am-9:06 am

1 stop23h 51m

Lambert-St Louis

Mon 9/29

4:00 pm-11:11 am

2 stops21h 11m

$252

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sat 9/13

5:38 am-3:09 pm

1 stop7h 31m

Lambert-St Louis

Sat 9/20

3:59 pm-9:27 pm

1 stop7h 28m

$255

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Thu 10/30

10:20 am-11:05 pm

2 stops10h 45m

Lambert-St Louis

Tue 11/4

4:00 pm-9:25 pm

1 stop7h 25m

$259

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Thu 9/11

6:05 am-9:06 am

1 stop25h 01m

Lambert-St Louis

Sun 9/14

6:20 am-1:24 pm

1 stop9h 04m

$260

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Sat 9/20

5:00 am-3:44 pm

2 stops8h 44m

Lambert-St Louis

Mon 9/29

5:15 am-9:29 am

1 stop6h 14m

$270

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Thu 9/11

3:23 pm-11:59 pm

1 stop6h 36m

Lambert-St Louis

Sat 9/13

7:23 am-2:33 pm

1 stop9h 10m

$303

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?

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

In general, January 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 $280. The month of September is another great option to travel to St. Louis, with average flight prices from Portland averaging around $310.

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 $379. 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 $596. 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 evening is the least expensive time of day to depart. momondo users have found prices as low as $288 when looking at flights departing in the evening. 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 $389 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 $271 on momondo.

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

There are 1 cabin classes 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 August 2025, prices for Portland to St. Louis flights are approximately 3% 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

Fastest flight time

3h 45m

Direct flights

Mon and Sun

Airports in St. Louis

1 airport
The fastest flight from Portland to St. Louis takes 3h 45m
Direct flights go from Portland to St. Louis on Monday and Sunday. There are no airlines offering direct flights.
There is 1 airport near St. Louis: 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 28m.

  • 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 $118Free CancellationRating
5.8
3,201 reviews
Search Frontier flights
DeltaPriceFrom $206Free CancellationRating
7.9
7,981 reviews
Search Delta flights
American AirlinesPriceFrom $226Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
United AirlinesPriceFrom $226Free CancellationRating
7.4
8,940 reviews
Search United Airlines flights
SouthwestPriceFrom $249Free CancellationRating
8.0
4,243 reviews
Search Southwest flights
Alaska AirlinesPriceFrom $262Free CancellationRating
8.0
10,000 reviews
Search Alaska Airlines flights

  • Southwest Flights From Portland to St. Louis

    Southwest is one of the most popular airlines flying from Portland to St. Louis, operating 1 flight/week on average for this route. A good Southwest flight deal for Portland to St. Louis starts from $249 round-trip, up to an average price of $450. Our users have rated Southwest at 8.0/10.

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
Maryland Heights
Florissant
O'Fallon
Fenton
Collinsville
Wentzville
Alton
St. Peters
Festus
Farmington
Glencoe
Clayton
Edwardsville
Eureka
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.

An easier way to manage your St. Louis trip

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