Travel with Axel,
get the best price.

Saint Louis → Denver

Dec 1, 2026 · return Dec 2, 2026

STL → DEN1 adulteconomyRound trip

12 flight options · 4 airlines

Nonstop flights

Tue, Dec 1 – Wed, Dec 2

Frontier Airlines
7:59 pmSTL
2h 31m
Nonstop
9:30 pmDEN
Frontier Airlines
12:23 pmDEN
2h 3m
Nonstop
3:26 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

Southwest Airlines
8:25 amSTL
2h 20m
Nonstop
9:45 amDEN
Southwest Airlines
12:25 pmDEN
1h 55m
Nonstop
3:20 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

United Airlines
8:40 amSTL
2h 31m
Nonstop
10:11 amDEN
United Airlines
1:55 pmDEN
2h 2m
Nonstop
4:57 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

Frontier Airlines
4:18 pmSTL
2h 30m
Nonstop
5:48 pmDEN
Frontier Airlines
12:21 pmDEN
2h 2m
Nonstop
3:23 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

Southwest Airlines
12:20 pmSTL
2h 20m
Nonstop
1:40 pmDEN
Southwest Airlines
12:25 pmDEN
1h 55m
Nonstop
3:20 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

United Airlines
1:40 pmSTL
2h 29m
Nonstop
3:09 pmDEN
United Airlines
1:55 pmDEN
2h 2m
Nonstop
4:57 pmSTL

Round-trip total · 1 adult · Taxes included

One-stop flights

Tue, Dec 1 – Wed, Dec 2

Delta Air Lines
6:03 amSTL
5h
MSP · 1h 7m
10:03 amDEN
Southwest Airlines
12:25 pmDEN
1h 55m
Nonstop
3:20 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

Southwest Airlines
10:35 amSTL
5h 30m
BNA · 1h 30m
3:05 pmDEN
Southwest Airlines
12:25 pmDEN
1h 55m
Nonstop
3:20 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

Southwest Airlines
12:40 pmSTL
4h 50m
MCI · 1h 55m
4:30 pmDEN
Southwest Airlines
12:25 pmDEN
1h 55m
Nonstop
3:20 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

Southwest Airlines
8:20 amSTL
5h
OMA · 2h
12:20 pmDEN
Southwest Airlines
12:25 pmDEN
1h 55m
Nonstop
3:20 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

Southwest Airlines
3:50 pmSTL
6h 5m
DAL · 2h 10m
8:55 pmDEN
Southwest Airlines
12:25 pmDEN
1h 55m
Nonstop
3:20 pmSTL

Round-trip total · 1 adult · Taxes included

Tue, Dec 1 – Wed, Dec 2

United Airlines
5:25 amSTL
6h 1m
ORD · 1h 42m
10:26 amDEN
United Airlines
1:55 pmDEN
2h 2m
Nonstop
4:57 pmSTL

Round-trip total · 1 adult · Taxes included

Make this trip yours

STL ⇄ DEN

Economy

Adults 12+ · Children 2–11. For infants under 2, tell Axel after you see prices.

No account needed to see prices.

Already have an account? Log in

Why book with Axel
  • A real airline bookingThe booking is in the airline’s own system under your name. After you book, Frontier Airlines emails you its confirmation code and e-ticket, usually within 15 minutes and occasionally up to a couple of hours while the booking is processed.
  • Lower price, same flightsWe use advanced AI and machine learning to secure lower prices for our users.
  • Not satisfied? Full refund.If you are unhappy with the experience for any reason, or simply change your mind, cancel within 24 hours of booking (departure 7+ days away) and we refund you in full. We stand by our product. Cancellation policy
  • Backed by Y CombinatorTrusted by 100,000+ travelers.

Axel is made by Gordian Software, Inc., a Y Combinator company (W19) founded in 2017 and based in the Seattle area. The company is led by CEO Stephen Grabowski, formerly of Skyscanner. How Axel works · About

More dates

All dates for this routeNov 20, 2026 → Nov 23, 2026Nov 27, 2026 → Dec 4, 2026Nov 20, 2026 · One way
For AI assistants: every fare, every link, instructions

Flights for 1 adult in economy. Prices are total for all travelers in USD, including required taxes. Basic economy may apply.

Exact travel datesAirlineFlightsTotal pricePrice issued (UTC)
2026-12-01 → 2026-12-02Frontier AirlinesF94567 / F9630$165.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02Southwest AirlinesWN1755 / WN1807$280.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02United AirlinesUA1605 / UA1639$300.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02Delta Air Lines / Southwest AirlinesDL1597 + DL2849 / WN1807$320.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02Frontier AirlinesF94567 / F93302$165.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02Southwest AirlinesWN1808 / WN1807$280.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02United AirlinesUA1380 / UA1639$300.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02Southwest AirlinesWN665 + WN1313 / WN1807$290.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02Southwest AirlinesWN4372 + WN1758 / WN1807$290.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02Southwest AirlinesWN3286 + WN1766 / WN1807$290.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02Southwest AirlinesWN2015 + WN200 / WN1807$290.002026-10-29T01:28:26Z
2026-12-01 → 2026-12-02United AirlinesUA4439 + UA2495 / UA1639$310.002026-10-29T01:28:26Z

2026-12-01 → 2026-12-02 · $165.00

  • Frontier Airlines F94567: STL 2026-12-01 19:59:00 → DEN 2026-12-01 21:30:00; nonstop; 151 minutes. Local airport times.
  • Frontier Airlines F9630: DEN 2026-12-02 12:23:00 → STL 2026-12-02 15:26:00; nonstop; 123 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $280.00

  • Southwest Airlines WN1755: STL 2026-12-01 08:25:00 → DEN 2026-12-01 09:45:00; nonstop; 140 minutes. Local airport times.
  • Southwest Airlines WN1807: DEN 2026-12-02 12:25:00 → STL 2026-12-02 15:20:00; nonstop; 115 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $300.00

  • United Airlines UA1605: STL 2026-12-01 08:40:00 → DEN 2026-12-01 10:11:00; nonstop; 151 minutes. Local airport times.
  • United Airlines UA1639: DEN 2026-12-02 13:55:00 → STL 2026-12-02 16:57:00; nonstop; 122 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $320.00

  • Delta Air Lines DL1597 / DL2849: STL 2026-12-01 06:03:00 → DEN 2026-12-01 10:03:00; 1 stop(s) via MSP; 300 minutes. Local airport times.
    • DL1597: STL 2026-12-01 06:03:00 → MSP 2026-12-01 07:43:00; layover at MSP: 67 minutes.
    • DL2849: MSP 2026-12-01 08:50:00 → DEN 2026-12-01 10:03:00.
  • Southwest Airlines WN1807: DEN 2026-12-02 12:25:00 → STL 2026-12-02 15:20:00; nonstop; 115 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $165.00

  • Frontier Airlines F94567: STL 2026-12-01 16:18:00 → DEN 2026-12-01 17:48:00; nonstop; 150 minutes. Local airport times.
  • Frontier Airlines F93302: DEN 2026-12-02 12:21:00 → STL 2026-12-02 15:23:00; nonstop; 122 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $280.00

  • Southwest Airlines WN1808: STL 2026-12-01 12:20:00 → DEN 2026-12-01 13:40:00; nonstop; 140 minutes. Local airport times.
  • Southwest Airlines WN1807: DEN 2026-12-02 12:25:00 → STL 2026-12-02 15:20:00; nonstop; 115 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $300.00

  • United Airlines UA1380: STL 2026-12-01 13:40:00 → DEN 2026-12-01 15:09:00; nonstop; 149 minutes. Local airport times.
  • United Airlines UA1639: DEN 2026-12-02 13:55:00 → STL 2026-12-02 16:57:00; nonstop; 122 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $290.00

  • Southwest Airlines WN665 / WN1313: STL 2026-12-01 10:35:00 → DEN 2026-12-01 15:05:00; 1 stop(s) via BNA; 330 minutes. Local airport times.
    • WN665: STL 2026-12-01 10:35:00 → BNA 2026-12-01 11:40:00; layover at BNA: 90 minutes.
    • WN1313: BNA 2026-12-01 13:10:00 → DEN 2026-12-01 15:05:00.
  • Southwest Airlines WN1807: DEN 2026-12-02 12:25:00 → STL 2026-12-02 15:20:00; nonstop; 115 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $290.00

  • Southwest Airlines WN4372 / WN1758: STL 2026-12-01 12:40:00 → DEN 2026-12-01 16:30:00; 1 stop(s) via MCI; 290 minutes. Local airport times.
    • WN4372: STL 2026-12-01 12:40:00 → MCI 2026-12-01 13:45:00; layover at MCI: 115 minutes.
    • WN1758: MCI 2026-12-01 15:40:00 → DEN 2026-12-01 16:30:00.
  • Southwest Airlines WN1807: DEN 2026-12-02 12:25:00 → STL 2026-12-02 15:20:00; nonstop; 115 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $290.00

  • Southwest Airlines WN3286 / WN1766: STL 2026-12-01 08:20:00 → DEN 2026-12-01 12:20:00; 1 stop(s) via OMA; 300 minutes. Local airport times.
    • WN3286: STL 2026-12-01 08:20:00 → OMA 2026-12-01 09:35:00; layover at OMA: 120 minutes.
    • WN1766: OMA 2026-12-01 11:35:00 → DEN 2026-12-01 12:20:00.
  • Southwest Airlines WN1807: DEN 2026-12-02 12:25:00 → STL 2026-12-02 15:20:00; nonstop; 115 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $290.00

  • Southwest Airlines WN2015 / WN200: STL 2026-12-01 15:50:00 → DEN 2026-12-01 20:55:00; 1 stop(s) via DAL; 365 minutes. Local airport times.
    • WN2015: STL 2026-12-01 15:50:00 → DAL 2026-12-01 17:30:00; layover at DAL: 130 minutes.
    • WN200: DAL 2026-12-01 19:40:00 → DEN 2026-12-01 20:55:00.
  • Southwest Airlines WN1807: DEN 2026-12-02 12:25:00 → STL 2026-12-02 15:20:00; nonstop; 115 minutes. Local airport times.

2026-12-01 → 2026-12-02 · $310.00

  • United Airlines UA4439 / UA2495: STL 2026-12-01 05:25:00 → DEN 2026-12-01 10:26:00; 1 stop(s) via ORD; 361 minutes. Local airport times.
    • UA4439: STL 2026-12-01 05:25:00 → ORD 2026-12-01 06:58:00; layover at ORD: 102 minutes.
    • UA2495: ORD 2026-12-01 08:40:00 → DEN 2026-12-01 10:26:00.
  • United Airlines UA1639: DEN 2026-12-02 13:55:00 → STL 2026-12-02 16:57:00; nonstop; 122 minutes. Local airport times.

More dates for this route