St. LouisSeattleDirect FlightsSTL–BFI
St. Louis (St. Louis Lambert International Airport) to Seattle (Boeing Field/King County International Airport).
Flight time from STL to BFI is estimated at about 4h 6m, based on the 1,706-mile great-circle distance. Our current captured departure sample includes Scheduled across 1 captured airline, with Alaska Airlines appearing most often in that sample.
Plan this routeAt a glance
| Est. flight time | Distance | Captured freq. | Type |
|---|---|---|---|
| ~4h 6m Estimated from great-circle distance — no tracked flights yet. | 1,706 mi | Scheduled From the current provider sample; confirm live timetables before booking. | Domestic |
Airlines on this route
Captured airlines for STL to BFI
Our current provider sample includes Scheduled from STL to BFI across 1 captured airline.
| Airline | Captured daily freq. | Aircraft | Departures (local) |
|---|---|---|---|
| Alaska Airlines | Scheduled | Varies by schedule | — |
Typical aircraft
Methodology: airline, aircraft, terminal, and departure-time details come from the rolling scheduled-departures window for STL to BFI, last seen June 15, 2026. Frequency uses 0 scheduled departures across 1 observed day; flight time is estimated from great-circle distance until this route has enough tracked flights for an observed average. Provider coverage can miss operators on some routes, so confirm live timetables before booking.
Route FAQ
How long is the flight from STL to BFI?
The STL to BFI flight time is estimated at about 4h 6m from great-circle distance until enough tracked flights are available.
How far is STL from BFI?
STL to BFI is about 1,706 miles by air.
Which airlines fly from STL to BFI?
Our current provider sample for STL to BFI includes Alaska Airlines. Confirm live timetables before booking.