St Louis to Seattle (STL–BFI) — Airlines, Schedules & Connections

STL Airport Page →
1,706 mi airlines 1/wk
On-time Some delays Frequent delays
Flight Schedule 0 flights Verified 1d ago
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  Flight Airline AC Dep Arr Dur OTP Sched  

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No nonstop flights on this route. connecting options below.

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St Louis to Seattle
1 carrier, 1 flights/week nonstop.
1 Airlines 1 Flights/wk 1,706 mi 3h 50m nonstop -2h behind 37 1-stop hubs

STL–BFI is served by 1 airline with nonstop service. Sun Country Airlines leads the route. The flight covers 1,706 miles in approximately 3h 50m. Beyond nonstop, 37 hubs offer 1-stop connections.

Also explore STL Routes BFI Routes STL Live Flights BFI Live Flights STL Delays
Carriers on this route

Airline Landscape

All carriers operating nonstop STL–BFI service, compared side by side.
Airline Freq/wk Aircraft Duration Dep OTP Alliance Codeshares
SY Sun Country Airlines 1 – – 80% – –
Alliance coverage
Unaffiliated: SY (1 flights/wk, 100%)
OTP based on airport-level delay snapshots. Duration ranges reflect seasonal/directional variation.
Connections

Connection Landscape

Beyond nonstop. 1-stop and 2-stop options for STL to BFI.
1-STOP
One-Stop Connections
37
Hubs
~4h
Fastest
~23h
Longest
DAL ~4h 47m IND ~5h 35m AUS ~5h 52m EGE ~5h 55m DFW ~6h 0m
Verified with published schedule alignment and minimum connection time.
2-STOP
Two-Stop Connections
279
Candidates
Two-stop connections loaded in the connections tab above.
Connections computed from published schedules with minimum connection time verification. Use the interactive explorer above the fold to filter by airline, tier, and layover time.
Reliability

On-Time Performance

What to expect at each end of your journey.
Outbound
STL → BFI
80%
Generally reliable. Most flights run on time.
Departing
80%
Return
BFI → STL
82%
Generally reliable. Most flights run on time.
Arriving
82%
OTP = percentage of flights arriving within 15 min of schedule. Based on airport-level delay snapshots. STL delays →
Know before you go

Travel Essentials

Practical planning for this route.
Time Difference
-2h
Seattle is 2 hours behind St Louis.
STL: EDT · BFI: MDT

When it's 6:00 PM in St Louis, it's 4:00 PM in Seattle.
Distance & Flight Time
1,706 mi / 2,745 km
Nonstop flight time is approximately 3h 50m.
Facts

STL–BFI Quick Facts

Key statistics for the St Louis to Seattle route.
Route details
Distance1,706 mi / 2,745 km
Flight time3h 50m
Time difference-2 hours
Airlines (nonstop)1
Weekly flights1 out
1-stop connections37 hubs
Origin: STL
Full nameSt. Louis Lambert International Airport
IATA / ICAOSTL / KSTL
TimezoneAmerica/Indiana/Vincennes
Passengers/yr15.6M
Elevation618 ft / 188 m
Destination: BFI
Full nameKing County International Airport - Boeing Field
IATA / ICAOBFI / KBFI
TimezoneAmerica/Boise
Passengers/yr0.1M
Elevation21 ft / 6 m
FAQ

Frequently Asked Questions

Common questions about STL to BFI flights.
Nonstop flights from St. Louis Lambert International Airport to King County International Airport - Boeing Field take approximately 3h 50m. The route covers 1,706 miles.
1 airline operates nonstop service: Sun Country Airlines.
There are approximately 1 nonstop flights per week from STL to BFI.
Yes, 1-stop connections are available through DAL, IND, AUS, EGE, DFW, OMA, BZN, CMH, ORD, LAS, PHX, SFO, IAH, BNA, SAN, SJC, IAD, SMF, SCF, DCA, BWI, PSP, CLT, OKC, MSP, EWR, JAX, RSW, YYZ, ATL, LAX, RDU, TPA, SLC, GCM, DEN and FLL. These options provide additional schedule flexibility.
Seattle is 2 hours behind St Louis.
Click the 'Search Flights' button to check availability and prices on Google Flights. You can also compare airlines and schedules on this page to find the best option.
See the On-Time Performance section for the latest delay data at both airports. This shows departure and arrival reliability to help you plan.
Route data is updated regularly from official airline schedules. On-time performance data comes from recent airport delay snapshots.

Flights from STL to BFI

St. Louis Lambert International Airport (STL) and King County International Airport - Boeing Field (BFI) are connected by nonstop service from Sun Country Airlines. With 1 weekly departures, this is a regularly served route.

STL to BFI Flight Duration and Schedule

Nonstop flight time from STL to BFI ranges from 3 hours 50 minutes. The route covers a distance of 1,706 miles (2,745 km).

Connecting Options and Alternatives

37 one-stop connections are available, with the fastest taking approximately 4 hours via DAL. Two-stop connections are also available via intermediate hubs.