St Louis to Ontario (STL–ONT) — Airlines, Schedules & Connections

STL Airport Page →
1,543 mi airlines charter/private 1/wk
On-time Some delays Frequent delays
Connecting Flight Schedule 27 1-stop flights Verified 3w ago
Also flown by charter / private operators.
Nonstop Charter / private 1-Stop 2-Stop Hide separate tickets Hide overnight Hide codeshares
  Flight Airline AC Dep Arr Dur OTP Sched  
✈ Nonstop

No flights match your filters.

No scheduled airline flights on this route — it's flown by charter / private operators (). No nonstop flights on this route. connecting options below.

✦ 1-Stop connections via 10 hubs
LAS Las Vegas 5h 15m F9WNY4 → F9WNY4 Las Vegas (LAS) to Ontario flights
PHX Phoenix 5h 17m AAASWN → AAPDWN Phoenix (PHX) to Ontario flights
DEN Denver 5h 25m ACF9UA → ACF9UA Denver (DEN) to Ontario flights
DAL Dallas 5h 33m EJALXJWN → WN Dallas (DAL) to Ontario flights
SLC Salt Lake City 5h 45m DLKELXJ → AFAMDL Salt Lake City (SLC) to Ontario flights
DFW Dallas-Fort Worth 5h 54m AAASAY → AABAF9 Dallas-Fort Worth (DFW) to Ontario flights
MDW Chicago 6h 10m WN → WN Chicago (MDW) to Ontario flights
BNA Nashville 6h 15m EJAWN → WN Nashville (BNA) to Ontario flights
SMF Sacramento 6h 20m WN → WN Sacramento (SMF) to Ontario flights
SFO San Francisco 6h 30m LXJOZUA → ACCMEJA San Francisco (SFO) to Ontario flights
✦ 1-STOP More options, longer trips
✧ 2-STOP Loading... Reach the hardest destinations
St Louis to Ontario
Connecting service available through multiple hubs.
1 Airlines 1,543 mi 4h 10m nonstop -2h behind

STL–ONT had nonstop service from Southwest Airlines, last on the schedule in May 2026. There's no nonstop on it right now, so today you'd fly it with one stop. The connecting options below are sorted by layover. Nonstop, it's about 1,543 miles in 4h 10m.

Also explore STL Routes ONT Routes STL Live Flights ONT Live Flights STL Delays ONT Delays
All flights from Ontario (ONT) Ontario to St Louis flights
Carriers on this route

Airline Landscape

Carriers that operated nonstop STL–ONT service, compared side by side.
Airline Freq/wk Aircraft Duration Dep OTP Alliance Codeshares
WN Southwest Airlines 1 – – 40% – –
Alliance coverage
Unaffiliated: WN (1 flights/wk, 100%)
OTP based on airport-level delay snapshots. Duration ranges reflect seasonal/directional variation.
Connections

Connection Landscape

1-stop and 2-stop options for STL to ONT.
1-STOP
One-Stop Connections
27
Hubs
~5h
Fastest
~32h
Longest
LAS ~5h 15m PHX ~5h 17m DEN ~5h 25m DAL ~5h 33m BUR ~5h 39m
Verified with published schedule alignment and minimum connection time.
2-STOP
Two-Stop Connections
1,164
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 → ONT
40%
Frequent delays expected. Consider flexible booking.
Departing
40%
Arriving
75%
Return
ONT → STL
72%
Moderate delays possible. Allow buffer time.
Departing
72%
Arriving
64%
OTP = percentage of flights arriving within 15 min of schedule. Based on airport-level delay snapshots. STL delays → ONT delays →
Know before you go

Travel Essentials

Practical planning for this route.
Time Difference
-2h
Ontario is 2 hours behind St Louis.
STL: CDT · ONT: PDT

When it's 6:00 PM in St Louis, it's 4:00 PM in Ontario.
Distance & Flight Time
1,543 mi / 2,483 km
Nonstop flight time is approximately 4h 10m gate to gate.
Facts

STL–ONT Quick Facts

Key statistics for the St Louis to Ontario route.
Route details
Distance1,543 mi / 2,483 km
Flight time4h 10m
Time difference-2 hours
Airlines (nonstop)1
1-stop connectionsAvailable
Origin: STL
Full nameSt. Louis Lambert International Airport
IATA / ICAOSTL / KSTL
TimezoneAmerica/Chicago
Passengers/yr15.6M
Elevation618 ft / 188 m
Destination: ONT
Full nameOntario International Airport
IATA / ICAOONT / KONT
TimezoneAmerica/Los_Angeles
Passengers/yr7.0M
Elevation944 ft / 288 m
FAQ

Frequently Asked Questions

Common questions about STL to ONT flights.
Nonstop flights from St. Louis Lambert International Airport to Ontario International Airport take about 4h 10m gate to gate. The route covers 1,543 miles.
1 airline operated the nonstop from STL to ONT: Southwest Airlines. The last scheduled nonstop was in May 2026. There's no nonstop right now, so today you'd fly it with one stop. See the connection options above, ranked by layover.
Not right now. The last scheduled nonstop was in May 2026. You can still fly it with one stop, and the connecting options above are sorted by layover. Nonstop, the hop took about 4h 10m.
Yes, 1-stop connections are available, ranked by layover time. Common connecting points include Harry Reid, Phoenix Sky Harbor and Denver.
Ontario 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 ONT

St. Louis Lambert International Airport (STL) and Ontario International Airport (ONT) had nonstop service from Southwest Airlines, last on the schedule in May 2026. The nonstop is dormant right now, so the way to fly it today is one connection, and the options above are sorted by layover.

STL to ONT Flight Duration and Schedule

Nonstop flight time from STL to ONT is about 4 hours 10 minutes gate to gate. The route covers a distance of 1,543 miles (2,483 km).

Connecting Options and Alternatives

1-stop connecting options are also available, commonly via Harry Reid, Phoenix Sky Harbor and Denver. Two-stop connections are also available via intermediate hubs.