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Ontario → Denver

Dec 21, 2026 · return Dec 25, 2026

ONT → DEN1 adulteconomyRound trip

11 flight options · 4 airlines

Nonstop flights

Mon, Dec 21 – Fri, Dec 25

Frontier Airlines
6:30 amONT
2h 21m
Nonstop
9:51 amDEN
Frontier Airlines
8:55 pmDEN
2h 22m
Nonstop
10:17 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

Southwest Airlines
8:45 amONT
2h 10m
Nonstop
11:55 amDEN
Southwest Airlines
12:45 pmDEN
2h 20m
Nonstop
2:05 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

United Airlines
5:00 amONT
2h 17m
Nonstop
8:17 amDEN
United Airlines
11:15 amDEN
2h 18m
Nonstop
12:33 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

Southwest Airlines
2:35 pmONT
2h 20m
Nonstop
5:55 pmDEN
Southwest Airlines
12:45 pmDEN
2h 20m
Nonstop
2:05 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

United Airlines
1:29 pmONT
2h 16m
Nonstop
4:45 pmDEN
United Airlines
11:15 amDEN
2h 18m
Nonstop
12:33 pmONT

Round-trip total · 1 adult · Taxes included

One-stop flights

Mon, Dec 21 – Fri, Dec 25

American Airlines
9:50 amONT
4h 24m
PHX · 1h 1m
3:14 pmDEN
American Airlines
12:06 pmDEN
5h 14m
PHX · 1h 53m
4:20 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

Frontier Airlines
8:44 amONT
5h
LAS · 1h 56m
2:44 pmDEN
Frontier Airlines
8:55 pmDEN
2h 22m
Nonstop
10:17 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

Southwest Airlines
2:00 pmONT
4h 5m
PHX · 1h
7:05 pmDEN
Southwest Airlines
12:45 pmDEN
2h 20m
Nonstop
2:05 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

Southwest Airlines
5:00 pmONT
5h 35m
LAS · 2h 35m
11:35 pmDEN
Southwest Airlines
12:45 pmDEN
2h 20m
Nonstop
2:05 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

Southwest Airlines
1:30 pmONT
5h 40m
SMF · 1h 55m
8:10 pmDEN
Southwest Airlines
12:45 pmDEN
2h 20m
Nonstop
2:05 pmONT

Round-trip total · 1 adult · Taxes included

Mon, Dec 21 – Fri, Dec 25

United Airlines
6:00 amONT
5h 9m
SFO · 1h
12:09 pmDEN
United Airlines
11:15 amDEN
2h 18m
Nonstop
12:33 pmONT

Round-trip total · 1 adult · Taxes included

Make this trip yours

ONT ⇄ DEN

Economy

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

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More dates

All dates for this routeNov 24, 2026 → Nov 29, 2026Dec 22, 2026 → Dec 27, 2026Dec 30, 2026 → Jan 2, 2027Jan 15, 2027 → Jan 18, 2027Oct 30, 2026 → Nov 2, 2026Oct 31, 2026 → Nov 7, 2026Nov 27, 2026 → Nov 30, 2026Nov 28, 2026 → Dec 5, 2026Dec 25, 2026 → Dec 28, 2026Dec 26, 2026 → Jan 2, 2027Jan 22, 2027 → Jan 25, 2027Oct 30, 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)
2026-12-21 → 2026-12-25Frontier AirlinesF91500 / F91499$174.002026-10-29T01:52:26Z
2026-12-21 → 2026-12-25Southwest AirlinesWN3301 / WN2484$391.502026-10-29T01:52:26Z
2026-12-21 → 2026-12-25United AirlinesUA2446 / UA430$406.002026-10-29T01:52:26Z
2026-12-21 → 2026-12-25American AirlinesAA1423 + AA3376 / AA2447 + AA4144$478.502026-10-29T01:52:26Z
2026-12-21 → 2026-12-25Southwest AirlinesWN2316 / WN2484$391.502026-10-29T01:52:26Z
2026-12-21 → 2026-12-25United AirlinesUA1263 / UA430$406.002026-10-29T01:52:26Z
2026-12-21 → 2026-12-25Frontier AirlinesF92232 + F91766 / F91499$217.502026-10-29T01:52:26Z
2026-12-21 → 2026-12-25Southwest AirlinesWN1533 + WN284 / WN2484$413.252026-10-29T01:52:26Z
2026-12-21 → 2026-12-25Southwest AirlinesWN1053 + WN1053 / WN2484$413.252026-10-29T01:52:26Z
2026-12-21 → 2026-12-25Southwest AirlinesWN3326 + WN1102 / WN2484$413.252026-10-29T01:52:26Z
2026-12-21 → 2026-12-25United AirlinesUA2363 + UA1068 / UA430$442.252026-10-29T01:52:26Z

2026-12-21 → 2026-12-25 · $174.00

  • Frontier Airlines F91500: ONT 2026-12-21 06:30:00 → DEN 2026-12-21 09:51:00; nonstop; 141 minutes. Local airport times.
  • Frontier Airlines F91499: DEN 2026-12-25 20:55:00 → ONT 2026-12-25 22:17:00; nonstop; 142 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $391.50

  • Southwest Airlines WN3301: ONT 2026-12-21 08:45:00 → DEN 2026-12-21 11:55:00; nonstop; 130 minutes. Local airport times.
  • Southwest Airlines WN2484: DEN 2026-12-25 12:45:00 → ONT 2026-12-25 14:05:00; nonstop; 140 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $406.00

  • United Airlines UA2446: ONT 2026-12-21 05:00:00 → DEN 2026-12-21 08:17:00; nonstop; 137 minutes. Local airport times.
  • United Airlines UA430: DEN 2026-12-25 11:15:00 → ONT 2026-12-25 12:33:00; nonstop; 138 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $478.50

  • American Airlines AA1423 / AA3376: ONT 2026-12-21 09:50:00 → DEN 2026-12-21 15:14:00; 1 stop(s) via PHX; 264 minutes. Local airport times.
    • AA1423: ONT 2026-12-21 09:50:00 → PHX 2026-12-21 12:15:00; layover at PHX: 61 minutes.
    • AA3376: PHX 2026-12-21 13:16:00 → DEN 2026-12-21 15:14:00.
  • American Airlines AA2447 / AA4144: DEN 2026-12-25 12:06:00 → ONT 2026-12-25 16:20:00; 1 stop(s) via PHX; 314 minutes. Local airport times.
    • AA2447: DEN 2026-12-25 12:06:00 → PHX 2026-12-25 14:03:00; layover at PHX: 113 minutes.
    • AA4144: PHX 2026-12-25 15:56:00 → ONT 2026-12-25 16:20:00.

2026-12-21 → 2026-12-25 · $391.50

  • Southwest Airlines WN2316: ONT 2026-12-21 14:35:00 → DEN 2026-12-21 17:55:00; nonstop; 140 minutes. Local airport times.
  • Southwest Airlines WN2484: DEN 2026-12-25 12:45:00 → ONT 2026-12-25 14:05:00; nonstop; 140 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $406.00

  • United Airlines UA1263: ONT 2026-12-21 13:29:00 → DEN 2026-12-21 16:45:00; nonstop; 136 minutes. Local airport times.
  • United Airlines UA430: DEN 2026-12-25 11:15:00 → ONT 2026-12-25 12:33:00; nonstop; 138 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $217.50

  • Frontier Airlines F92232 / F91766: ONT 2026-12-21 08:44:00 → DEN 2026-12-21 14:44:00; 1 stop(s) via LAS; 300 minutes. Local airport times.
    • F92232: ONT 2026-12-21 08:44:00 → LAS 2026-12-21 09:50:00; layover at LAS: 116 minutes.
    • F91766: LAS 2026-12-21 11:46:00 → DEN 2026-12-21 14:44:00.
  • Frontier Airlines F91499: DEN 2026-12-25 20:55:00 → ONT 2026-12-25 22:17:00; nonstop; 142 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $413.25

  • Southwest Airlines WN1533 / WN284: ONT 2026-12-21 14:00:00 → DEN 2026-12-21 19:05:00; 1 stop(s) via PHX; 245 minutes. Local airport times.
    • WN1533: ONT 2026-12-21 14:00:00 → PHX 2026-12-21 16:15:00; layover at PHX: 60 minutes.
    • WN284: PHX 2026-12-21 17:15:00 → DEN 2026-12-21 19:05:00.
  • Southwest Airlines WN2484: DEN 2026-12-25 12:45:00 → ONT 2026-12-25 14:05:00; nonstop; 140 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $413.25

  • Southwest Airlines WN1053 / WN1053: ONT 2026-12-21 17:00:00 → DEN 2026-12-21 23:35:00; 1 stop(s) via LAS; 335 minutes. Local airport times.
    • WN1053: ONT 2026-12-21 17:00:00 → LAS 2026-12-21 18:05:00; layover at LAS: 155 minutes.
    • WN1053: LAS 2026-12-21 20:40:00 → DEN 2026-12-21 23:35:00.
  • Southwest Airlines WN2484: DEN 2026-12-25 12:45:00 → ONT 2026-12-25 14:05:00; nonstop; 140 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $413.25

  • Southwest Airlines WN3326 / WN1102: ONT 2026-12-21 13:30:00 → DEN 2026-12-21 20:10:00; 1 stop(s) via SMF; 340 minutes. Local airport times.
    • WN3326: ONT 2026-12-21 13:30:00 → SMF 2026-12-21 14:55:00; layover at SMF: 115 minutes.
    • WN1102: SMF 2026-12-21 16:50:00 → DEN 2026-12-21 20:10:00.
  • Southwest Airlines WN2484: DEN 2026-12-25 12:45:00 → ONT 2026-12-25 14:05:00; nonstop; 140 minutes. Local airport times.

2026-12-21 → 2026-12-25 · $442.25

  • United Airlines UA2363 / UA1068: ONT 2026-12-21 06:00:00 → DEN 2026-12-21 12:09:00; 1 stop(s) via SFO; 309 minutes. Local airport times.
    • UA2363: ONT 2026-12-21 06:00:00 → SFO 2026-12-21 07:30:00; layover at SFO: 60 minutes.
    • UA1068: SFO 2026-12-21 08:30:00 → DEN 2026-12-21 12:09:00.
  • United Airlines UA430: DEN 2026-12-25 11:15:00 → ONT 2026-12-25 12:33:00; nonstop; 138 minutes. Local airport times.

More dates for this route