Cheapest€226.70
- Alaska Airlines AA867814:274h 35m19:02Seattle BFISt. Louis STL
Door to door 7h 45mCO2 701.6 kgChanges 0Fixed, no changes
Seattle to St Louis flight
Flights from Seattle to St Louis start at €285.70 and take 7h 23m at their fastest.
The Flights from Seattle to St Louis starts at €285.70 and takes 7h 23m door to door, run by 2 operators over 2,852 km, with around 8 departures a day. Fares bottom out about 60 days before departure.
- 7h 23mDoor to door
- 4h 13mMoving
- €285.70From
- 701.6 kgCO2
The cheapest and the fastest on September 29, 2026
Two journeys we can sell today, with the service number each operator files them under.
Fastest€291.01
- Southwest Airlines SA157014:074h 13m18:20Seattle SEASt. Louis STL
Door to door 7h 23mCO2 701.6 kgChanges 0Fixed, no changes
Lowest CO2€291.01
- Alaska Airlines AA444007:304h 4m11:34Seattle SEAKansas City MCI
- Amtrak A288513:113h 3m16:14Union StationUnion Station
Changes at Kansas City, with 97 minutes between services and a walk of about 14 minutes.
Door to door 10h 41mCO2 625.4 kgChanges 1Fixed, no changes
Airlines
Speed, flexibility and what is on board. Nothing here is a rating, because we have not earned one.
| Operator | From |
|---|---|
 Alaska Airlines | €226.70 |
 Southwest Airlines | €240.27 |
The trip ends at Union Station. Everything past the gates belongs to somebody else, the rooms included.
Rooms within reach of Union Station
Sort by distance from Union Station and you can see which places are ten minutes on foot and which are not.
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When to book Seattle to St Louis
The same search run across the whole booking window, so the shape of the curve is visible rather than described.
- €302.2290 days
- €181.8660 days
- €189.5345 days
- €198.9730 days
- €280.3921 days
- €362.4014 days
- €345.297 days
- €337.623 days
- €534.091 days
- Cheapest lead time
- Fares bottom out around 60 days ahead, at €181.86.
- How much it moves
- The gap between the cheapest and most expensive lead time is 194 percent. The most expensive point is €534.09, 1 days out.
- What that means
- Today sits inside the cheap window, which closes about 60 days before departure. Waiting from here has usually cost money on this corridor rather than saved it.
Which departure day costs least
Median cheapest fare for each weekday, taken across the next three weeks of real prices.
- €332.31Sun
- €285.70Mon
- €296.32Tue
- €302.81Wed
- €375.97Thu
- €386.00Fri
- €345.29Sat
Where you leave from and where you arrive
The stations, airports and ports each mode on this corridor actually uses.
Seattle
Air
- SEA
- BFI
St. Louis
Air
- STL
What the journey actually looks like
Direct or connecting, how far the route really runs, and what happens when a connection is missed.
- Direct or connecting
- 50% of the services we sell on this corridor run through without a change. The remaining 50% involve one connection.
- How far it really runs
- The route covers 2,852 km against 2,769 km in a straight line, a detour of 3 percent. Track and road geometry account for the difference.
- Where the change is
- Connections are made at Minneapolis, Denver, Omaha, Kansas City. The gap between arriving and leaving is 63 minutes, of which about 5 is walking.
- If the connection is missed
- The tightest connection we sell here has a 15 percent chance of not being made on the timetable alone. Part of this journey is a self transfer between separate tickets, so leave more time than the minimum and expect to check in again.
- First and last departure
- The first service of the day leaves Seattle at 06:40 and the last at 14:27, across 8 departures. The return direction keeps its own timetable, so the times back are not these times reversed.
Questions about Seattle to St Louis
The questions people actually ask about this trip, answered from the same prices and times the page above is built on rather than written once and left to go stale.
How long does the Flight from Seattle to St Louis take?
The Flight from Seattle to St Louis takes 7h 23m door to door, of which 4h 13m is spent moving. The route runs 2,852 km. The difference between the two times is reaching the terminal and leaving it at the far end, which every time on this page includes.
How much does the Flight from Seattle to St Louis cost?
The Flight from Seattle to St Louis starts at €285.70 for one passenger, checked on September 12, 2026. A typical fare is €280.69. Both are the total including taxes, supplier fees and our service fee, so the price here is the price at checkout.
Who runs the Flight from Seattle to St Louis?
2 operators run the Flight from Seattle to St Louis: Alaska Airlines, Southwest Airlines. Between them they file around 8 departures a day. The operator table on this page compares them on fare, journey time, cruising speed, fare conditions and what is provided on board.
Which terminal does the Flight from Seattle to St Louis use?
The Flight from Seattle to St Louis leaves from Seattle SEA and arrives at St. Louis STL. Allow about 3h 10m for reaching the departure terminal and leaving the arrival one. That time is already inside every door to door figure quoted on this page.
When should I book the Flight from Seattle to St Louis?
Fares for the Flight from Seattle to St Louis bottom out around 60 days ahead, at €181.86. The gap between the cheapest and most expensive lead time across the window is 194 percent, measured on September 12, 2026. Booking inside the final week has consistently cost more.
How much CO2 does the Flight from Seattle to St Louis produce?
The Flight from Seattle to St Louis produces about 701.6 kg of CO2 per passenger over 2852 km, which works out at roughly 246 grams per passenger kilometer. That figure is for the whole journey and for one traveler, not for the vehicle.
Where these numbers come from
Observed service A carrier record shows this named operator serving this named pair, and we carry that through unchanged.
Schedules, seat counts and fares are generated by our own model until the supplier contracts are signed. Places, coordinates, operators, which operator serves which pair, and every distance are real. We would rather say that on every page than let a modeled number pass for a filed one.
Defined in full at Door to door, Fares, The booking window, Carbon
- On this page
- Every figure above was computed for Seattle to St Louis on September 12, 2026: 2852 km of route against 2769 km in a straight line, 8 services a day, 2 operators, a cheapest fare of €285.70, and 7h 23m door to door on the fastest mode. The return direction is computed separately and its numbers are not these numbers.
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