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Cheap flights from St. Louis to Washington from $63

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 Washington departing on 1/7. 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 St. Louis to Washington

Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
2:38 pm - 8:57 pm
STL
-
SEA
8h 19m1 stop
American Airlines Logo
7:35 am - 4:14 pm
SEA
-
STL
6h 39m1 stop
$176American Airlines
Thu, Jan 8 - Thu, Jan 15
Delta Logo
3:40 pm - 8:46 pm
STL
-
SEA
7h 06m1 stop
Delta Logo
1:38 pm - 9:38 pm
SEA
-
STL
6h 00m1 stop
$177Delta
Sat, Jan 17 - Tue, Jan 20
Frontier Logo
7:43 pm - 11:21 am
STL
-
SEA
17h 38m1 stop
Frontier Logo
10:51 am - 2:46 pm
SEA
-
STL
25h 55m2 stops
$179Frontier
Wed, Jan 7 - Fri, Jan 30
Frontier Logo
10:01 pm - 9:36 am
STL
-
SEA
13h 35m1 stop
Frontier Logo
6:30 pm - 3:53 pm
SEA
-
STL
19h 23m2 stops
$182Frontier
Thu, Jan 29 - Tue, Feb 10
American Airlines Logo
7:15 am - 3:34 pm
STL
-
SEA
10h 19m1 stop
American Airlines Logo
9:45 pm - 9:40 am
SEA
-
STL
9h 55m1 stop
$184American Airlines
Fri, Jan 9 - Mon, Jan 19
Alaska Airlines Logo
6:19 pm - 8:54 pm
STL
-
SEA
4h 35mnonstop
Alaska Airlines Logo
7:55 am - 1:54 pm
SEA
-
STL
3h 59mnonstop
$197Alaska Airlines
Sat, Jan 17 - Tue, Jan 20
Delta Logo
6:10 am - 10:55 am
STL
-
SEA
6h 45m1 stop
Delta Logo
5:00 am - 1:48 pm
SEA
-
STL
6h 48m1 stop
$198Delta
Thu, Jan 15 - Thu, Jan 22
Alaska Airlines Logo
6:20 pm - 8:30 pm
STL
-
PDX
4h 10mnonstop
Alaska Airlines Logo
1:25 pm - 12:04 am
PDX
-
STL
8h 39m1 stop
$239Alaska Airlines
Wed, May 13 - Mon, May 18
United Airlines Logo
11:20 am - 9:12 pm
STL
-
PDX
11h 52m2 stops
United Airlines Logo
1:24 pm - 8:58 pm
PDX
-
STL
5h 34m1 stop
$254United Airlines
Tue, Jan 13 - Tue, Jan 20
United Airlines Logo
11:25 am - 9:07 pm
STL
-
GEG
11h 42m2 stops
United Airlines Logo
5:00 am - 1:14 pm
GEG
-
STL
6h 14m1 stop
$410United Airlines
Wed, Feb 25 - Sat, Feb 28

American Airlines flights from St. Louis to State of Washington

Our best American Airlines deals on St. Louis to State of Washington flight tickets
American Airlines
Jan 8
STL2:38 pmLambert-St Louis
8h 19m
1 stop
SEA8:57 pmSeattle/Tacoma Intl
Jan 15
SEA7:35 amSeattle/Tacoma Intl
6h 39m
1 stop
STL4:14 pmLambert-St Louis
$176
Find similar
American Airlines
Jan 9
STL7:15 amLambert-St Louis
10h 19m
1 stop
SEA3:34 pmSeattle/Tacoma Intl
Jan 19
SEA9:45 pmSeattle/Tacoma Intl
9h 55m
1 stop
STL9:40 amLambert-St Louis
$184
Find similar
American Airlines
Jan 12
STL3:37 pmLambert-St Louis
10h 14m
1 stop
SEA11:51 pmSeattle/Tacoma Intl
Jan 19
SEA9:45 pmSeattle/Tacoma Intl
9h 55m
1 stop
STL9:40 amLambert-St Louis
$193
Find similar

Delta flights from St. Louis to State of Washington

Our best Delta deals on St. Louis to State of Washington flight tickets
Delta
Jan 17
STL3:40 pmLambert-St Louis
7h 06m
1 stop
SEA8:46 pmSeattle/Tacoma Intl
Jan 20
SEA1:38 pmSeattle/Tacoma Intl
6h 00m
1 stop
STL9:38 pmLambert-St Louis
$177
Find similar
Delta
Jan 15
STL6:10 amLambert-St Louis
6h 45m
1 stop
SEA10:55 amSeattle/Tacoma Intl
Jan 22
SEA5:00 amSeattle/Tacoma Intl
6h 48m
1 stop
STL1:48 pmLambert-St Louis
$198
Find similar
Delta
Mar 20
STL5:29 pmLambert-St Louis
8h 24m
1 stop
SEA11:53 pmSeattle/Tacoma Intl
Mar 23
SEA11:59 pmSeattle/Tacoma Intl
6h 51m
1 stop
STL8:50 amLambert-St Louis
$209
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to State of Washington 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 December 18, 2025.
Use the filters below to find and compare flights from St. Louis to Washington that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 1/8

2:38 pm-8:57 pm

1 stop8h 19m

Seattle/Tacoma Intl

Thu 1/15

7:35 am-4:14 pm

1 stop6h 39m

$176

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Sat 1/17

3:40 pm-8:46 pm

1 stop7h 06m

Seattle/Tacoma Intl

Tue 1/20

1:38 pm-9:38 pm

1 stop6h 00m

$177

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 1/7

7:43 pm-11:21 am

1 stop17h 38m

Seattle/Tacoma Intl

Fri 1/30

10:51 am-2:46 pm

2 stops25h 55m

$179

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 1/29

10:01 pm-9:36 am

1 stop13h 35m

Seattle/Tacoma Intl

Tue 2/10

6:30 pm-3:53 pm

2 stops19h 23m

$182

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Fri 1/9

7:15 am-3:34 pm

1 stop10h 19m

Seattle/Tacoma Intl

Mon 1/19

9:45 pm-9:40 am

1 stop9h 55m

$184

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Sat 1/17

6:19 pm-8:54 pm

Nonstop4h 35m

Seattle/Tacoma Intl

Tue 1/20

7:55 am-1:54 pm

Nonstop3h 59m

$197

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 1/15

6:10 am-10:55 am

1 stop6h 45m

Seattle/Tacoma Intl

Thu 1/22

5:00 am-1:48 pm

1 stop6h 48m

$198

St. LouisPortland

STL - PDX

STLPDX

Lambert-St Louis

Wed 5/13

6:20 pm-8:30 pm

Nonstop4h 10m

Portland

Mon 5/18

1:25 pm-12:04 am

1 stop8h 39m

$239

St. LouisPortland

STL - PDX

STLPDX

Lambert-St Louis

Tue 1/13

11:20 am-9:12 pm

2 stops11h 52m

Portland

Tue 1/20

1:24 pm-8:58 pm

1 stop5h 34m

$254

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Wed 2/25

11:25 am-9:07 pm

2 stops11h 42m

Spokane

Sat 2/28

5:00 am-1:14 pm

1 stop6h 14m

$410

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 Washington from

How to get the cheapest flight ticket from St. Louis to State of Washington

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 State of Washington?

The month of October is, on average, the cheapest month to fly to State of Washington from St. Louis, with most prices found around $249. If you aren’t able to travel to State of Washington during the month of October, then flying in November is also cheap. Prices for this month can be found on momondo for an average of $264.

What is the cheapest day to depart on your flight to State of Washington?

The cheapest day to depart from St. Louis to State of Washington is on a Tuesday. Travelers who choose to depart for State of Washington on a Tuesday will often find tickets for as low as $453. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from St. Louis to State of Washington for around $569.

What is the cheapest time of day to depart on your flight to State of Washington?

The cheapest time of day to fly to State of Washington is in the afternoon when flights can be purchased for as low as $450. If you have a flexible travel schedule, then try to avoid flying at noon when prices are $510 on average. Flights to State of Washington from St. Louis at noon are generally more expensive because this time of day is more convenient for travelers’ schedules.

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

Fly from Lambert-St Louis to Seattle/Tacoma Intl for the best Lambert-St Louis - Washington flight prices

How far in advance should I book a flight to State of Washington?

You are more likely to see cheaper flights to State of Washington from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to State of Washington for around $339 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to State of Washington from St. Louis for as low as $292 on momondo.

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

There are 4 cabin classes available to choose from on Lambert-St Louis to Washington 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 St. Louis to State of Washington flights?

You could potentially save up to 31% on your flight if you consider stops on a St. Louis to State of Washington flight.

Cheap St. Louis to State of Washington flight deals and tips

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

Best Price Found

$157

Fastest flight time

4h 10m

Direct flights

Every day

Airports in State of Washington

96 airports
The best one-way flight to State of Washington from St. Louis in the past 72 hours is $157. The best round-trip flight deal from St. Louis to State of Washington found on momondo in the last 72 hours is $303.
The fastest flight from St. Louis to State of Washington takes 4h 10m
Direct flights go from St. Louis to State of Washington every day.
There are 96 airports in State of Washington. From St. Louis there are direct flights to Portland (PDX), Seattle/Tacoma Intl (SEA).
Search flight deals

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

    Prices for flights from Lambert-St Louis Airport to Washington refresh daily.

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

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

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Washington.

  • What documentation or ID do you need to fly to Washington?

    The travel and health documents you'll need for your trip to Washington 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 Washington. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from St. Louis to State of Washington?

Best airlines flying from St. Louis to State of Washington

Compare and see reviews for airlines that fly from St. Louis to State of Washington with momondo
Airline
Rating
Free Cancellation
Price
DeltaPriceFrom $94Free CancellationRating
7.9
8,007 reviews
Search Delta flights
FrontierPriceFrom $120Free CancellationRating
5.8
3,080 reviews
Search Frontier flights
SouthwestPriceFrom $176Free CancellationRating
7.9
4,252 reviews
Search Southwest flights
American AirlinesPriceFrom $188Free CancellationRating
7.2
11,054 reviews
Search American Airlines flights
United AirlinesPriceFrom $193Free CancellationRating
7.4
9,094 reviews
Search United Airlines flights
Hawaiian AirlinesPriceFrom $237Free CancellationRating
7.8
2,820 reviews
Search Hawaiian Airlines flights
Alaska AirlinesPriceFrom $237Free CancellationRating
8.0
11,479 reviews
Search Alaska Airlines flights

Why use momondo?

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

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Washington from St. Louis.

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

Yes. momondo allows you to filter the results for St. Louis to Washington flights to just show those with flexible booking policies.

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

Once you have performed a search for St. Louis to Washington 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 St. Louis to Washington right now. Can momondo alert me if prices change?

Price alerts on flights to Washington 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 State of Washington trip

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