$58+ Cheap flights from Ontario (ONT) to Colorado
This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/9. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — DEN
Mar 5 — Mar 121
1 adult, Economy
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Find cheap flights from Ontario to Colorado with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Ontario to Colorado
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Cheapest flights from Ontario to ColoradoExplore the most affordable flight options available from Ontario to Colorado. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 3, 2026.
Explore the most affordable flight options available from Ontario to Colorado. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 3, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/216:00 am
ONT
- DEN
Nonstop2h 20m
Frontier
Wed 2/258:00 pm
DEN
- ONT
Nonstop2h 34m
Frontier
Deal found 2/1![Frontier logo]()
$77
This Super.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/66:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Mon 3/910:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/2![Frontier logo]()
$78
This Cheapflightsfares deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/276:00 am
ONT
- DEN
Nonstop2h 20m
Frontier
Sun 3/16:20 am
DEN
- ONT
Nonstop2h 39m
Frontier
Deal found 2/3![Frontier logo]()
$80
This Cheapflightsfares deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/26:10 am
ONT
- DEN
Nonstop2h 20m
Frontier
Mon 3/910:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$82
This Super.com deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/48:40 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 3/710:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 1/31![Frontier logo]()
$83
This Frontier deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/286:00 am
ONT
- DEN
Nonstop2h 20m
Frontier
Sun 3/810:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$84
This Super.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/248:35 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 2/2810:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/2![Frontier logo]()
$86
This Super.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/48:40 am
ONT
- DEN
Nonstop2h 24m
Frontier
Wed 3/48:00 pm
DEN
- ONT
Nonstop2h 34m
Frontier
Deal found 2/2![Frontier logo]()
$88
This Frontier deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/48:40 am
ONT
- DEN
Nonstop2h 24m
Frontier
Wed 3/1110:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/3![Frontier logo]()
$90
This Super.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/108:36 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 2/2810:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$91
This Frontier deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/257:17 pm
ONT
- DEN
1 stop7h 39m
Frontier
Tue 3/1010:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$92
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:00 am
ONT
- COS
1 stop4h 24m
Delta
Sat 4/118:15 am
COS
- ONT
1 stop5h 08m
Delta
Deal found 1/31![Delta logo]()
$257
Best flights from Ontario to ColoradoDiscover carefully curated flight deals from Ontario to Colorado that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 3, 2026.
Discover carefully curated flight deals from Ontario to Colorado that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 3, 2026.
This Delta deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/283:30 pm
ONT
- DEN
1 stop6h 55m
Delta
Mon 3/96:15 pm
DEN
- ONT
1 stop6h 36m
Delta
Deal found 2/1![Delta logo]()
$217
This Southwest deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/116:00 am
ONT
- DEN
2 stops7h 40m
Southwest
Wed 4/153:35 pm
DEN
- ONT
1 stop4h 35m
Southwest
Deal found 2/1![Southwest logo]()
$242
This United Airlines deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/35:00 am
ONT
- DEN
Nonstop2h 16m
United Airlines
Sat 3/711:20 am
DEN
- ONT
Nonstop2h 28m
United Airlines
Deal found 2/3![United Airlines logo]()
$247
This American Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/911:58 pm
ONT
- ASE
1 stop9h 13m
American Airlines
Fri 3/1310:24 am
ASE
- ONT
1 stop6h 58m
American Airlines
Deal found 2/2![American Airlines logo]()
$421
This Delta deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/253:30 pm
ONT
- DEN
1 stop6h 55m
Delta
Fri 3/66:20 pm
DEN
- ONT
1 stop6h 29m
Delta
Deal found 2/1![Delta logo]()
$217
This United Airlines deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/185:10 am
ONT
- COS
1 stop6h 26m
United Airlines
Mon 4/205:13 pm
COS
- ONT
1 stop4h 23m
United Airlines
Deal found 2/1![United Airlines logo]()
$257
This Delta deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/271:10 pm
ONT
- DEN
1 stop6h 04m
Delta
Mon 3/96:15 pm
DEN
- ONT
1 stop6h 36m
Delta
Deal found 2/1![Delta logo]()
$237
This Southwest deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/145:40 am
ONT
- DEN
2 stops5h 20m
Southwest
Sat 3/217:45 pm
DEN
- ONT
1 stop4h 50m
Southwest
Deal found 2/1![Southwest logo]()
$262
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:00 am
ONT
- DEN
1 stop4h 33m
Delta
Fri 4/106:15 pm
DEN
- ONT
1 stop6h 36m
Delta
Deal found 1/31![Delta logo]()
$237
This United Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/221:34 pm
ONT
- DRO
1 stop6h 20m
United Airlines
Mon 4/277:00 am
DRO
- ONT
1 stop6h 38m
United Airlines
Deal found 2/2![United Airlines logo]()
$264
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/46:00 am
ONT
- DEN
1 stop4h 26m
Delta
Wed 4/86:15 pm
DEN
- ONT
1 stop6h 36m
Delta
Deal found 1/31![Delta logo]()
$237
This United Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/255:00 am
ONT
- DEN
Nonstop2h 16m
United Airlines
Sat 2/287:20 pm
DEN
- ONT
Nonstop2h 30m
United Airlines
Deal found 2/2![United Airlines logo]()
$267
This Delta deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/263:30 pm
ONT
- DEN
1 stop6h 55m
Delta
Thu 3/56:20 pm
DEN
- ONT
1 stop6h 29m
Delta
Deal found 2/1![Delta logo]()
$237
This United Airlines deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/245:00 am
ONT
- DEN
Nonstop2h 16m
United Airlines
Sat 2/2811:15 am
DEN
- ONT
Nonstop2h 28m
United Airlines
Deal found 1/31![United Airlines logo]()
$267
This United Airlines deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/225:00 am
ONT
- ASE
1 stop4h 36m
United Airlines
Sun 5/248:32 am
ASE
- ONT
1 stop5h 00m
United Airlines
Deal found 2/1![United Airlines logo]()
$269
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:00 am
ONT
- COS
1 stop4h 24m
Delta
Tue 4/78:15 am
COS
- ONT
1 stop5h 08m
Delta
Deal found 1/31![Delta logo]()
$257
This United Airlines deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/255:15 am
ONT
- MTJ
1 stop6h 17m
United Airlines
Sun 3/293:37 pm
MTJ
- ONT
1 stop5h 59m
United Airlines
Deal found 2/1![United Airlines logo]()
$281
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:00 am
ONT
- COS
1 stop4h 24m
Delta
Sat 4/118:15 am
COS
- ONT
1 stop5h 08m
Delta
Deal found 1/31![Delta logo]()
$257
This United Airlines deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/205:00 am
ONT
- GJT
1 stop6h 47m
United Airlines
Wed 2/257:05 am
GJT
- ONT
1 stop6h 38m
United Airlines
Deal found 2/3![United Airlines logo]()
$281
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/75:09 pm
ONT
- COS
1 stop3h 56m
Delta
Sat 4/1112:10 pm
COS
- ONT
1 stop5h 18m
Delta
Deal found 1/31![Delta logo]()
$257
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/105:09 pm
ONT
- DEN
1 stop4h 22m
Delta
Tue 4/146:55 am
DEN
- ONT
1 stop7h 44m
Delta
Deal found 1/31![Delta logo]()
$257
This United Airlines deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 7/125:00 am
ONT
- MTJ
1 stop6h 38m
United Airlines
Sat 7/187:15 am
MTJ
- ONT
1 stop6h 17m
United Airlines
Deal found 2/1![United Airlines logo]()
$309
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/26:00 am
ONT
- COS
1 stop4h 24m
Delta
Tue 4/78:15 am
COS
- ONT
1 stop5h 08m
Delta
Deal found 1/31![Delta logo]()
$296
This United Airlines deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/25:10 am
ONT
- COS
1 stop4h 55m
United Airlines
Sat 4/41:33 pm
COS
- ONT
2 stops10h 12m
United Airlines
Deal found 2/1![United Airlines logo]()
$327
This United Airlines deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/75:10 am
ONT
- COS
1 stop4h 55m
United Airlines
Tue 4/75:13 pm
COS
- ONT
1 stop4h 23m
United Airlines
Deal found 1/31![United Airlines logo]()
$327
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/46:00 am
ONT
- COS
1 stop4h 24m
Delta
Sun 4/128:15 am
COS
- ONT
1 stop5h 08m
Delta
Deal found 1/31![Delta logo]()
$322
This United Airlines deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/275:00 am
ONT
- MTJ
1 stop6h 27m
United Airlines
Mon 3/23:33 pm
MTJ
- ONT
1 stop6h 17m
United Airlines
Deal found 2/1![United Airlines logo]()
$330
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/76:00 am
ONT
- COS
1 stop4h 24m
Delta
Sun 4/128:15 am
COS
- ONT
1 stop5h 08m
Delta
Deal found 1/31![Delta logo]()
$322
This United Airlines deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/41:45 pm
ONT
- MTJ
1 stop5h 36m
United Airlines
Sun 3/87:36 am
MTJ
- ONT
1 stop6h 12m
United Airlines
Deal found 2/1![United Airlines logo]()
$330
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:00 am
ONT
- COS
1 stop4h 24m
Delta
Sun 4/128:15 am
COS
- ONT
1 stop5h 08m
Delta
Deal found 1/31![Delta logo]()
$322
Last-minute flights from Ontario to ColoradoDiscover last-minute flight deals from Ontario to Colorado. Data last updated February 3, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Colorado. Data last updated February 3, 2026 and is based on user searches.
This Super.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/86:20 am
ONT
- DEN
Nonstop2h 20m
Frontier
Wed 2/118:00 pm
DEN
- ONT
Nonstop2h 34m
Frontier
Deal found 2/1![Frontier logo]()
$110
This Super.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/108:36 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 2/2810:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$91
This Cheapflightsfares deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/108:36 am
ONT
- DEN
Nonstop2h 24m
Frontier
Tue 2/248:00 pm
DEN
- ONT
Nonstop2h 34m
Frontier
Deal found 2/2![Frontier logo]()
$93
This Super.com deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/108:36 am
ONT
- DEN
Nonstop2h 24m
Frontier
Wed 2/118:00 pm
DEN
- ONT
Nonstop2h 34m
Frontier
Deal found 2/2![Frontier logo]()
$96
This Kiwi.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/118:10 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 2/2810:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$92
This Cheapflightsfares deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/118:10 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 2/1410:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$102
This Cheapflightsfares deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/118:10 am
ONT
- DEN
Nonstop2h 24m
Frontier
Wed 2/118:00 pm
DEN
- ONT
Nonstop2h 34m
Frontier
Deal found 2/1![Frontier logo]()
$126
This Cheapflightsfares deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/118:10 am
ONT
- DEN
Nonstop2h 24m
Frontier
Wed 2/188:00 pm
DEN
- ONT
Nonstop2h 34m
Frontier
Deal found 2/1![Frontier logo]()
$127
This Super.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/136:00 am
ONT
- DEN
Nonstop2h 20m
Frontier
Fri 2/2010:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$87
This Cheapflightsfares deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/136:00 am
ONT
- DEN
Nonstop2h 20m
Frontier
Sun 2/156:20 am
DEN
- ONT
Nonstop2h 39m
Frontier
Deal found 2/2![Frontier logo]()
$98
This Super.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/136:00 am
ONT
- DEN
Nonstop2h 20m
Frontier
Sat 2/1410:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 2/1![Frontier logo]()
$100
This United Airlines deal was found by Cheapflights users on 2/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/95:15 am
ONT
- ASE
1 stop5h 05m
United Airlines
Sat 3/141:40 pm
ASE
- ONT
1 stop4h 58m
United Airlines
Deal found 2/2![United Airlines logo]()
$269
One-way flights from Ontario to ColoradoSearch for one-way flight options from Ontario to Colorado. Find affordable one-way fares based on user searches. Data last updated February 3, 2026.
Search for one-way flight options from Ontario to Colorado. Find affordable one-way fares based on user searches. Data last updated February 3, 2026.
This WAYA deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WAYA is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/99:40 pm
ONT
- DEN
1 stop5h 16m
Frontier
Deal found 2/1![Frontier logo]()
$58
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/32:06 pm
ONT
- DEN
1 stop12h 50m
Frontier
Deal found 2/3![Frontier logo]()
$61
This Super.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/48:40 am
ONT
- DEN
Nonstop2h 24m
Frontier
Deal found 2/3![Frontier logo]()
$62
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/206:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Deal found 2/3![Frontier logo]()
$63
This Super.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/112:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Deal found 2/3![Frontier logo]()
$64
This Super.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/243:22 pm
ONT
- DEN
1 stop11h 34m
Frontier
Deal found 2/3![Frontier logo]()
$68
This Frontier deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/257:17 pm
ONT
- DEN
1 stop7h 39m
Frontier
Deal found 2/1![Frontier logo]()
$70
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/71:09 pm
ONT
- DEN
1 stop13h 50m
Frontier
Deal found 2/3![Frontier logo]()
$71
This Kiwi.com deal was found by Cheapflights users on 2/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/163:30 pm
ONT
- DEN
1 stop11h 26m
Frontier
Deal found 2/3![Frontier logo]()
$72
This Super.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/231:18 pm
ONT
- DEN
1 stop7h 01m
Frontier
Deal found 2/1![Frontier logo]()
$73
This Delta deal was found by Cheapflights users on 1/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:00 am
ONT
- COS
1 stop4h 24m
Delta
Deal found 1/31![Delta logo]()
$129
This Kiwi.com deal was found by Cheapflights users on 2/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/2210:18 pm
ONT
- COS
2 stops17h 09m
Multiple Airlines
Deal found 2/1![Multiple Airlines logo]()
$132
Find flight deals from Ontario to Colorado
Keep the following information in mind while searching for Ontario to Colorado flight deals. Data was last updated February 3, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $77 (Cheapflightsfares) |
One-way from | $58 (WAYA) |
Popular in | June |
Cheapest in | September |
Average price | $177 |
Good round-trip deal | $182 or less |
Good one-way deal | $111 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Ontario to Colorado that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 3, 2026.
Use the filters below to find and compare flights from Ontario to Colorado that are best for you.
Fly from
Ontario
Fly to
Colorado
Route
Depart
Return
Price
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 2/28
3:30 pm-11:25 pm
1 stop6h 55m
Denver Intl
Mon 3/9
6:15 pm-11:51 pm
1 stop6h 36m
$217
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Wed 2/25
3:30 pm-11:25 pm
1 stop6h 55m
Denver Intl
Fri 3/6
6:20 pm-11:49 pm
1 stop6h 29m
$217
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Fri 2/27
1:10 pm-8:14 pm
1 stop6h 04m
Denver Intl
Mon 3/9
6:15 pm-11:51 pm
1 stop6h 36m
$237
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Wed 4/1
6:00 am-11:33 am
1 stop4h 33m
Denver Intl
Fri 4/10
6:15 pm-11:51 pm
1 stop6h 36m
$237
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 4/4
6:00 am-11:26 am
1 stop4h 26m
Denver Intl
Wed 4/8
6:15 pm-11:51 pm
1 stop6h 36m
$237
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Thu 2/26
3:30 pm-11:25 pm
1 stop6h 55m
Denver Intl
Thu 3/5
6:20 pm-11:49 pm
1 stop6h 29m
$237
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 4/11
6:00 am-2:40 pm
2 stops7h 40m
Denver Intl
Wed 4/15
3:35 pm-7:10 pm
1 stop4h 35m
$242
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Tue 3/3
5:00 am-8:16 am
Nonstop2h 16m
Denver Intl
Sat 3/7
11:20 am-12:48 pm
Nonstop2h 28m
$247
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Sat 4/18
5:10 am-12:36 pm
1 stop6h 26m
Colorado Springs
Mon 4/20
5:13 pm-8:36 pm
1 stop4h 23m
$257
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Wed 4/1
6:00 am-11:24 am
1 stop4h 24m
Colorado Springs
Tue 4/7
8:15 am-12:23 pm
1 stop5h 08m
$257
Showing 1-10 of 60 results
Best time to book a flight from Ontario to Colorado
Have a flexible travel schedule? Discover the best time to fly to Colorado from Ontario with our price prediction graph.
ONT-DEN
ONT-ASE
ONT-COS
ONT-DRO
ONT-MTJ
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from Ontario to Colorado
ONT-USCO
ONT-DEN
ONT-ASE
ONT-COS
ONT-DRO
What is the cheapest month to book a flight from Ontario to Colorado?
Currently, March is the cheapest month in which you can book a flight from Ontario to Colorado (average of $36). Flying from Ontario to Colorado in September is currently the most expensive (average of $76). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from ONT to CO?
Find hourly flight availability from Ontario to Colorado. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated February 3, 2026.
It’s typically best to fly out from Ontario to Colorado in the evening. Doing so could potentially save you 53% on the flight price compared to flying at noon, which is usually more expensive.
What is the cheapest day to fly from Ontario to Colorado?
Use this chart to determine the cheapest time to fly round-trip from Ontario to Colorado. Price data was last updated on January 31, 2026.
Travelers seeking maximum savings on their Ontario to Colorado flight should consider departing on Tuesday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
Weekly flight availability from Ontario to Colorado
Explore weekly flight availability from Ontario to Colorado. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated February 3, 2026.
The most flights from ONT to USCO are scheduled on a Monday (8 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (4 on average).
Reviews of airlines servicing Colorado
Get insights into the airlines that provide service to Colorado. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Colorado. Reviews last updated February 3, 2026.
See what other customers who have flown with Southwest, Delta, and United Airlines from Ontario to Colorado have to say. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Crew
8.6
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Crew
8.6
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Crew
8.6
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Crew
8.6
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Crew
8.6
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Crew
8.6
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Related info for your journey
Find useful and relevant information for your journey from Ontario to Colorado. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Browse thousands of different options on Cheapflights for your next trip
Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
Alternative routes for Ontario to Colorado
See prices for flight routes from nearby airports that may be better suited for you.
Top 5 airlines flying from Ontario to Colorado
Discover the top 5 airlines that operate flights from Ontario to Colorado. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 3, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$58 | Average$151 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$109 | Average$265 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$117 | Average$312 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$130 | Average$355 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$211 | Average$371 | FlexibilityNo cancel fee | On-time71% |