Plan to arrive at SEA two hours before your flight. Use SEA Spot Saver for security appointments to reduce wait times.

Most accurate provider | eDreams 3 stars |
|---|---|
Most trusted provider | eDreams 3 stars |
Round-trip from | $240 (Kiwi.com) |
One-way from | $59 (Trip.com) |
Popular in | December |
Cheapest in | September |
Average price | $389 |
Good round-trip deal | $359 or less |
Good one-way deal | $174 or less |
Fly from
Fly to
Route
Depart
Return
Price
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Fri 12/5
7:15 am-12:48 am
2 stops15h 33m
Lambert-St Louis
Mon 12/8
6:30 am-12:57 pm
1 stop8h 27m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Thu 12/11
5:15 am-5:15 pm
2 stops10h 00m
Lambert-St Louis
Sun 12/14
5:30 am-10:40 am
1 stop7h 10m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Wed 12/3
11:15 pm-7:10 pm
2 stops17h 55m
Lambert-St Louis
Sat 12/6
6:00 am-12:58 pm
1 stop8h 58m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Thu 11/27
11:10 pm-9:46 am
1 stop8h 36m
Lambert-St Louis
Tue 12/16
6:00 am-10:54 am
1 stop6h 54m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Sat 12/6
5:00 am-5:00 pm
2 stops10h 00m
Lambert-St Louis
Tue 12/9
2:25 pm-10:55 pm
2 stops10h 30m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Wed 12/10
5:15 am-5:15 pm
2 stops10h 00m
Lambert-St Louis
Sun 12/14
5:15 pm-12:30 am
2 stops9h 15m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Sun 3/1
6:05 am-4:47 pm
1 stop8h 42m
Lambert-St Louis
Tue 3/3
7:00 am-2:44 pm
1 stop9h 44m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Thu 12/11
5:15 am-5:15 pm
2 stops10h 00m
Lambert-St Louis
Thu 12/18
1:40 pm-8:35 pm
2 stops8h 55m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Wed 2/18
9:00 am-10:59 pm
2 stops11h 59m
Lambert-St Louis
Sat 2/21
5:29 pm-11:30 pm
1 stop8h 01m
SeattleSt. Louis
SEA - STL
SEASTL
Seattle/Tacoma Intl
Thu 12/4
7:00 am-3:40 pm
1 stop6h 40m
Lambert-St Louis
Wed 12/10
1:35 pm-11:15 pm
2 stops11h 40m
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*2 stars | |
| Price Accuracy- | Trust Score*1 star |
The best time to book flights from Seattle to St. Louis is 67 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
Currently, July is the cheapest month in which you can book a flight from Seattle to St. Louis (average of $163). Flying from Seattle to St. Louis in March is currently the most expensive (average of $230). 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.
When flying from Seattle to St. Louis, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 38% versus a flight in the morning.
Travelers seeking maximum savings on their Seattle to St. Louis flight should consider departing on Tuesday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
Comfort
Food
Overall
Entertainment
Boarding
Crew
Reviews
Anonymous,Sep 2025
SEA - MKE
Comfort
Food
Overall
Entertainment
Boarding
Crew
Reviews
Anonymous,Sep 2025
SEA - MKE
Comfort
Food
Overall
Entertainment
Boarding
Crew
Reviews
Anonymous,Sep 2025
SEA - MKE
Comfort
Food
Overall
Entertainment
Boarding
Crew
Reviews
Anonymous,Sep 2025
SEA - MKE
Comfort
Food
Overall
Entertainment
Boarding
Crew
Reviews
Anonymous,Sep 2025
SEA - MKE
Comfort
Food
Overall
Entertainment
Boarding
Crew
Reviews
Anonymous,Sep 2025
SEA - MKE
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$134 | Average$289 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$137 | Average$294 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$182 | Average$340 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$186 | Average$488 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$216 | Average$340 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$219 | Average$395 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$247 | Average$420 | FlexibilityNo cancel fee | On-time75% |