Cheapest€107.52
- Frontier Airlines FA965616:432h 19m19:02Denver DENSt. Louis STL
Door to door 5h 29mCO2 324.0 kgChanges 0Fixed, no changes
Denver to St Louis flight
Flights from Denver to St Louis start at €127.58 and take 5h 14m at their fastest.
The Flights from Denver to St Louis starts at €127.58 and takes 5h 14m door to door, run by 5 operators over 1,317 km, with around 40 departures a day. Fares bottom out about 45 days before departure.
- 5h 14mDoor to door
- 2h 4mMoving
- €127.58From
- 324.0 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€148.23
- Frontier Airlines FA820606:272h 4m08:31Denver DENSt. Louis STL
Door to door 5h 14mCO2 324.0 kgChanges 0Fixed, no changes
Airlines
Speed, flexibility and what is on board. Nothing here is a rating, because we have not earned one.
| Operator | From |
|---|---|
 Frontier Airlines | €107.52 |
 GoJet Airlines | €111.65 |
 SkyWest | €110.47 |
| United Airlines | €108.70 |
 Southwest Airlines | €113.42 |
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 Denver to St Louis
The same search run across the whole booking window, so the shape of the curve is visible rather than described.
- €126.9990 days
- €87.4660 days
- €86.8745 days
- €89.2330 days
- €128.7621 days
- €165.3414 days
- €198.977 days
- €191.303 days
- €262.101 days
- Cheapest lead time
- Fares bottom out around 45 days ahead, at €86.87.
- How much it moves
- The gap between the cheapest and most expensive lead time is 202 percent. The most expensive point is €262.10, 1 days out.
- What that means
- Today sits inside the cheap window, which closes about 45 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.
- €155.31Sun
- €130.53Mon
- €127.58Tue
- €138.79Wed
- €181.27Thu
- €164.16Fri
- €165.34Sat
Where you leave from and where you arrive
The stations, airports and ports each mode on this corridor actually uses.
Denver
Air
- DEN
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.
- How far it really runs
- The route covers 1,317 km against 1,279 km in a straight line, a detour of 3 percent. Track and road geometry account for the difference.
- First and last departure
- The first service of the day leaves Denver at 06:27 and the last at 20:53, across 40 departures. The return direction keeps its own timetable, so the times back are not these times reversed.
Questions about Denver 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 Denver to St Louis take?
The Flight from Denver to St Louis takes 5h 14m door to door, of which 2h 4m is spent moving. The route runs 1,317 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 Denver to St Louis cost?
The Flight from Denver to St Louis starts at €127.58 for one passenger, checked on September 12, 2026. A typical fare is €134.96. 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 Denver to St Louis?
5 operators run the Flight from Denver to St Louis: Frontier Airlines, GoJet Airlines, SkyWest, United Airlines, Southwest Airlines. Between them they file around 40 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 Denver to St Louis use?
The Flight from Denver to St Louis leaves from Denver DEN 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 Denver to St Louis?
Fares for the Flight from Denver to St Louis bottom out around 45 days ahead, at €86.87. The gap between the cheapest and most expensive lead time across the window is 202 percent, measured on September 12, 2026. Booking inside the final week has consistently cost more.
How much CO2 does the Flight from Denver to St Louis produce?
The Flight from Denver to St Louis produces about 324.0 kg of CO2 per passenger over 1317 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 Denver to St Louis on September 12, 2026: 1317 km of route against 1279 km in a straight line, 40 services a day, 5 operators, a cheapest fare of €127.58, and 5h 14m door to door on the fastest mode. The return direction is computed separately and its numbers are not these numbers.
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