$85+ 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 4/22. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — DEN
May 18 — May 251
Round-trip
1 adult, Economy
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Find cheap flights from Ontario to Colorado with Cheapflights
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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 April 18, 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 April 18, 2026.
This Super.com deal was found by Cheapflights users on 4/13. 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 5/176:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/1910:29 pm
DEN
- ONT
Nonstop2h 20m
Frontier
Deal found 4/13![Frontier logo]()
$91
This Cheapflightsfares deal was found by Cheapflights users on 4/13. 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 6/176:00 am
ONT
- DEN
Nonstop2h 26m
Frontier
Wed 6/248:44 am
DEN
- ONT
Nonstop2h 21m
Frontier
Deal found 4/13![Frontier logo]()
$92
This Super.com deal was found by Cheapflights users on 4/13. 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.
Thu 5/76:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Mon 5/118:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/13![Frontier logo]()
$97
This Frontier deal was found by Cheapflights users on 4/14. 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 5/66:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Sat 5/1612:34 pm
DEN
- ONT
1 stop7h 58m
Frontier
Deal found 4/14![Frontier logo]()
$98
This Cheapflightsfares deal was found by Cheapflights users on 4/14. 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 5/276:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Fri 5/298:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/14![Frontier logo]()
$101
This Frontier deal was found by Cheapflights users on 4/14. 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.
Fri 5/86:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Wed 5/138:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/14![Frontier logo]()
$102
This Cheapflightsfares deal was found by Cheapflights users on 4/16. 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.
Thu 5/76:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Sun 5/1010:29 pm
DEN
- ONT
1 stop10h 20m
Frontier
Deal found 4/16![Frontier logo]()
$103
This Super.com deal was found by Cheapflights users on 4/14. 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 5/86:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Sat 5/168:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/14![Frontier logo]()
$107
This Southwest deal was found by Cheapflights users on 4/14. 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.
Tue 5/122:25 pm
ONT
- COS
1 stop5h 20m
Southwest
Tue 5/196:00 am
COS
- ONT
1 stop4h 50m
Southwest
Deal found 4/14![Southwest logo]()
$189
This Kiwi.com deal was found by Cheapflights users on 4/15. 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 5/2511:51 am
ONT
- GJT
1 stop23h 22m
Multiple Airlines
Sun 5/311:23 pm
GJT
- ONT
1 stop26h 46m
Multiple Airlines
Deal found 4/15![Multiple Airlines logo]()
$196
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/65:00 am
ONT
- COS
1 stop5h 05m
United Airlines
Tue 5/121:25 pm
COS
- ONT
2 stops10h 34m
United Airlines
Deal found 4/13![United Airlines logo]()
$202
This Kiwi.com deal was found by Cheapflights users on 4/15. 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 5/253:30 pm
ONT
- GJT
1 stop19h 43m
Multiple Airlines
Tue 6/212:53 pm
GJT
- ONT
1 stop7h 39m
Multiple Airlines
Deal found 4/15![Multiple Airlines logo]()
$207
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 April 18, 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 April 18, 2026.
This Southwest deal was found by Cheapflights users on 4/14. 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.
Tue 5/122:25 pm
ONT
- COS
1 stop5h 20m
Southwest
Tue 5/196:00 am
COS
- ONT
1 stop4h 50m
Southwest
Deal found 4/14![Southwest logo]()
$189
This Delta deal was found by Cheapflights users on 4/13. 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.
Mon 5/45:05 pm
ONT
- COS
1 stop4h 08m
Delta
Tue 5/128:15 am
COS
- ONT
1 stop5h 04m
Delta
Deal found 4/13![Delta logo]()
$209
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/51:40 pm
ONT
- DRO
1 stop6h 26m
United Airlines
Sat 5/97:00 am
DRO
- ONT
1 stop6h 38m
United Airlines
Deal found 4/13![United Airlines logo]()
$327
This American Airlines deal was found by Cheapflights users on 4/17. 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.
Sat 5/26:15 am
ONT
- EGE
2 stops11h 54m
American Airlines
Wed 5/68:00 am
EGE
- ONT
1 stop6h 18m
American Airlines
Deal found 4/17![American Airlines logo]()
$334
This Alaska Airlines deal was found by Cheapflights users on 4/12. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/233:26 pm
ONT
- DEN
1 stop7h 33m
Alaska Airlines
Sun 4/266:00 am
DEN
- ONT
1 stop9h 32m
Alaska Airlines
Deal found 4/12![Alaska Airlines logo]()
$422
This Delta deal was found by Cheapflights users on 4/12. 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 5/281:35 pm
ONT
- DEN
1 stop9h 17m
Delta
Mon 6/15:30 am
DEN
- ONT
1 stop4h 23m
Delta
Deal found 4/12![Delta logo]()
$219
This Southwest deal was found by Cheapflights users on 4/17. 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 5/301:20 pm
ONT
- COS
1 stop6h 25m
Southwest
Mon 6/16:15 am
COS
- ONT
1 stop5h 40m
Southwest
Deal found 4/17![Southwest logo]()
$249
This Southwest deal was found by Cheapflights users on 4/12. 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 5/166:00 am
ONT
- DEN
2 stops7h 40m
Southwest
Sat 5/233:20 pm
DEN
- ONT
1 stop4h 50m
Southwest
Deal found 4/12![Southwest logo]()
$263
This Delta deal was found by Cheapflights users on 4/15. 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 5/274:57 pm
ONT
- GJT
1 stop4h 03m
Delta
Wed 6/36:51 pm
GJT
- ONT
1 stop5h 43m
Delta
Deal found 4/15![Delta logo]()
$271
This Delta deal was found by Cheapflights users on 4/15. 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.
Mon 5/251:29 pm
ONT
- GJT
1 stop3h 47m
Delta
Fri 6/56:51 pm
GJT
- ONT
1 stop5h 43m
Delta
Deal found 4/15![Delta logo]()
$271
This United Airlines deal was found by Cheapflights users on 4/15. 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 5/85:00 am
ONT
- DEN
Nonstop2h 22m
United Airlines
Mon 5/117:45 am
DEN
- ONT
1 stop5h 37m
United Airlines
Deal found 4/15![United Airlines logo]()
$328
This Southwest deal was found by Cheapflights users on 4/15. 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.
Tue 5/1912:40 pm
ONT
- DEN
1 stop4h 40m
Southwest
Sat 5/231:15 pm
DEN
- ONT
2 stops6h 55m
Southwest
Deal found 4/15![Southwest logo]()
$272
This Delta deal was found by Cheapflights users on 4/15. 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 5/274:57 pm
ONT
- GJT
1 stop4h 03m
Delta
Fri 6/56:51 pm
GJT
- ONT
1 stop5h 43m
Delta
Deal found 4/15![Delta logo]()
$271
This United Airlines deal was found by Cheapflights users on 4/14. 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 5/51:40 pm
ONT
- MTJ
1 stop5h 38m
United Airlines
Wed 5/61:43 pm
MTJ
- ONT
2 stops10h 16m
United Airlines
Deal found 4/14![United Airlines logo]()
$334
This Delta deal was found by Cheapflights users on 4/15. 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 5/284:57 pm
ONT
- GJT
1 stop4h 03m
Delta
Sun 5/316:51 pm
GJT
- ONT
1 stop5h 43m
Delta
Deal found 4/15![Delta logo]()
$271
This Southwest deal was found by Cheapflights users on 4/16. 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.
Mon 6/85:15 pm
ONT
- DEN
1 stop4h 05m
Southwest
Wed 6/1011:55 am
DEN
- ONT
2 stops6h 10m
Southwest
Deal found 4/16![Southwest logo]()
$302
This American Airlines deal was found by Cheapflights users on 4/13. 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.
Tue 5/196:15 am
ONT
- DRO
1 stop3h 56m
American Airlines
Fri 5/226:48 pm
DRO
- ONT
1 stop4h 09m
American Airlines
Deal found 4/13![American Airlines logo]()
$404
This United Airlines deal was found by Cheapflights users on 4/12. 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 5/21:40 pm
ONT
- DEN
Nonstop2h 22m
United Airlines
Mon 5/47:10 pm
DEN
- ONT
Nonstop2h 26m
United Airlines
Deal found 4/12![United Airlines logo]()
$340
This United Airlines deal was found by Cheapflights users on 4/16. 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 5/25:00 am
ONT
- DRO
1 stop5h 06m
United Airlines
Tue 5/511:41 am
DRO
- ONT
2 stops12h 18m
United Airlines
Deal found 4/16![United Airlines logo]()
$346
This American Airlines deal was found by Cheapflights users on 4/14. 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.
Fri 5/89:24 am
ONT
- EGE
2 stops8h 45m
American Airlines
Sun 5/108:00 am
EGE
- ONT
1 stop6h 18m
American Airlines
Deal found 4/14![American Airlines logo]()
$426
This Southwest deal was found by Cheapflights users on 4/13. 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.
Tue 6/96:35 pm
ONT
- DEN
1 stop3h 40m
Southwest
Sat 6/1310:00 am
DEN
- ONT
2 stops8h 35m
Southwest
Deal found 4/13![Southwest logo]()
$328
This Delta deal was found by Cheapflights users on 4/15. 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 5/294:57 pm
ONT
- GJT
1 stop4h 03m
Delta
Fri 6/56:51 pm
GJT
- ONT
1 stop5h 43m
Delta
Deal found 4/15![Delta logo]()
$305
This United Airlines deal was found by Cheapflights users on 4/13. 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 4/285:10 am
ONT
- DRO
1 stop4h 44m
United Airlines
Sat 5/21:35 pm
DRO
- ONT
2 stops10h 24m
United Airlines
Deal found 4/13![United Airlines logo]()
$346
This United Airlines deal was found by Cheapflights users on 4/16. 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 5/275:00 am
ONT
- DRO
1 stop6h 28m
United Airlines
Wed 6/31:30 pm
DRO
- ONT
1 stop4h 58m
United Airlines
Deal found 4/16![United Airlines logo]()
$348
This Delta deal was found by Cheapflights users on 4/14. 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.
Mon 6/11:29 pm
ONT
- GJT
1 stop3h 47m
Delta
Wed 6/36:51 pm
GJT
- ONT
1 stop5h 43m
Delta
Deal found 4/14![Delta logo]()
$332
This Southwest deal was found by Cheapflights users on 4/16. 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 5/28:40 am
ONT
- COS
2 stops6h 00m
Southwest
Wed 5/64:45 pm
COS
- ONT
1 stop6h 00m
Southwest
Deal found 4/16![Southwest logo]()
$374
This United Airlines deal was found by Cheapflights users on 4/14. 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 5/55:00 am
ONT
- GJT
1 stop4h 43m
United Airlines
Sat 5/97:00 am
GJT
- ONT
1 stop6h 38m
United Airlines
Deal found 4/14![United Airlines logo]()
$351
This Delta deal was found by Cheapflights users on 4/12. 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 5/301:35 pm
ONT
- DEN
1 stop9h 17m
Delta
Sun 5/315:30 am
DEN
- ONT
1 stop4h 23m
Delta
Deal found 4/12![Delta logo]()
$338
This Southwest deal was found by Cheapflights users on 4/13. 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.
Fri 6/264:40 pm
ONT
- COS
2 stops7h 40m
Southwest
Mon 6/299:05 pm
COS
- ONT
1 stop4h 00m
Southwest
Deal found 4/13![Southwest logo]()
$384
This United Airlines deal was found by Cheapflights users on 4/16. 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 5/35:00 am
ONT
- GJT
1 stop4h 43m
United Airlines
Sat 5/91:48 pm
GJT
- ONT
2 stops10h 11m
United Airlines
Deal found 4/16![United Airlines logo]()
$356
Last-minute flights from Ontario to ColoradoDiscover last-minute flight deals from Ontario to Colorado. Data last updated April 18, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Colorado. Data last updated April 18, 2026 and is based on user searches.
This Super.com deal was found by Cheapflights users on 4/15. 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 4/2112:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Wed 4/2910:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 4/15![Frontier logo]()
$137
This Super.com deal was found by Cheapflights users on 4/15. 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 4/2112:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Thu 4/236:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 4/15![Frontier logo]()
$151
This Frontier deal was found by Cheapflights users on 4/13. 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.
Fri 4/2412:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 5/36:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 4/13![Frontier logo]()
$143
This Cheapflightsfares deal was found by Cheapflights users on 4/12. 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 4/2412:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Mon 4/2710:00 am
DEN
- ONT
1 stop4h 10m
Frontier
Deal found 4/12![Frontier logo]()
$168
This Super.com deal was found by Cheapflights users on 4/13. 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 4/2412:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sat 5/210:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 4/13![Frontier logo]()
$171
This Frontier deal was found by Cheapflights users on 4/13. 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.
Fri 4/249:12 am
ONT
- DEN
1 stop6h 22m
Frontier
Sun 5/36:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 4/13![Frontier logo]()
$175
This Cheapflightsfares deal was found by Cheapflights users on 4/13. 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 4/2512:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 5/108:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/13![Frontier logo]()
$167
This Frontier deal was found by Cheapflights users on 4/13. 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 4/2512:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 5/36:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 4/13![Frontier logo]()
$173
This Cheapflightsfares deal was found by Cheapflights users on 4/16. 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 4/279:12 am
ONT
- DEN
1 stop6h 22m
Frontier
Sun 5/36:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 4/16![Frontier logo]()
$169
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/65:00 am
ONT
- COS
1 stop5h 05m
United Airlines
Tue 5/121:25 pm
COS
- ONT
2 stops10h 34m
United Airlines
Deal found 4/13![United Airlines logo]()
$202
This Southwest deal was found by Cheapflights users on 4/14. 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.
Tue 5/122:25 pm
ONT
- COS
1 stop5h 20m
Southwest
Tue 5/196:00 am
COS
- ONT
1 stop4h 50m
Southwest
Deal found 4/14![Southwest logo]()
$189
This Kiwi.com deal was found by Cheapflights users on 4/15. 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 5/2511:51 am
ONT
- GJT
1 stop23h 22m
Multiple Airlines
Sun 5/311:23 pm
GJT
- ONT
1 stop26h 46m
Multiple Airlines
Deal found 4/15![Multiple Airlines logo]()
$196
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 April 18, 2026.
Search for one-way flight options from Ontario to Colorado. Find affordable one-way fares based on user searches. Data last updated April 18, 2026.
This Frontier deal was found by Cheapflights users on 4/14. 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 4/2212:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Deal found 4/14![Frontier logo]()
$85
This Kiwi.com deal was found by Cheapflights users on 4/14. 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.
Thu 5/2811:51 am
ONT
- DEN
1 stop11h 18m
Frontier
Deal found 4/14![Frontier logo]()
$86
This Kiwi.com deal was found by Cheapflights users on 4/14. 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 5/48:26 am
ONT
- DEN
1 stop22h 40m
Frontier
Deal found 4/14![Frontier logo]()
$88
This Super.com deal was found by Cheapflights users on 4/14. 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.
Thu 4/309:20 pm
ONT
- DEN
1 stop5h 39m
Frontier
Deal found 4/14![Frontier logo]()
$89
This Cheapflightsfares deal was found by Cheapflights users on 4/14. 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 5/211:44 am
ONT
- DEN
1 stop7h 16m
Frontier
Deal found 4/14![Frontier logo]()
$90
This Frontier deal was found by Cheapflights users on 4/16. 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.
Tue 5/54:39 pm
ONT
- DEN
1 stop6h 30m
Frontier
Deal found 4/16![Frontier logo]()
$91
This Super.com deal was found by Cheapflights users on 4/13. 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 4/2812:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Deal found 4/13![Frontier logo]()
$93
This Southwest deal was found by Cheapflights users on 4/15. 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.
Tue 6/166:35 pm
ONT
- COS
1 stop4h 10m
Southwest
Deal found 4/15![Southwest logo]()
$95
This Super.com deal was found by Cheapflights users on 4/14. 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 5/39:19 am
ONT
- DEN
1 stop23h 28m
Frontier
Deal found 4/14![Frontier logo]()
$95
This Cheapflightsfares deal was found by Cheapflights users on 4/14. 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 5/158:06 pm
ONT
- DEN
1 stop11h 00m
Frontier
Deal found 4/14![Frontier logo]()
$96
This Frontier deal was found by Cheapflights users on 4/14. 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.
Fri 5/88:44 am
ONT
- DEN
1 stop8h 20m
Frontier
Deal found 4/14![Frontier logo]()
$97
This Delta deal was found by Cheapflights users on 4/15. 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 5/126:00 am
ONT
- COS
1 stop4h 15m
Delta
Deal found 4/15![Delta logo]()
$110
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 April 18, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $91 (Super.com) |
One-way from | $85 (Frontier) |
Popular in | March |
Cheapest in | September |
Average price | $226 |
Good round-trip deal | $246 or less |
Good one-way deal | $160 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 April 18, 2026.
Use the filters below to find and compare flights from Ontario to Colorado that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Tue 5/12
2:25 pm-8:45 pm
1 stop5h 20m
Colorado Springs
Tue 5/19
6:00 am-9:50 am
1 stop4h 50m
$189
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Mon 5/4
5:05 pm-10:13 pm
1 stop4h 08m
Colorado Springs
Tue 5/12
8:15 am-12:19 pm
1 stop5h 04m
$209
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Thu 5/28
1:35 pm-11:52 pm
1 stop9h 17m
Denver Intl
Mon 6/1
5:30 am-8:53 am
1 stop4h 23m
$219
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Sat 5/30
1:20 pm-8:45 pm
1 stop6h 25m
Colorado Springs
Mon 6/1
6:15 am-10:55 am
1 stop5h 40m
$249
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 5/16
6:00 am-2:40 pm
2 stops7h 40m
Denver Intl
Sat 5/23
3:20 pm-7:10 pm
1 stop4h 50m
$263
OntarioGrand Junction
ONT - GJT
ONTGJT
Ontario
Wed 5/27
4:57 pm-10:00 pm
1 stop4h 03m
Grand Junction Regnl
Wed 6/3
6:51 pm-11:34 pm
1 stop5h 43m
$271
OntarioGrand Junction
ONT - GJT
ONTGJT
Ontario
Mon 5/25
1:29 pm-6:16 pm
1 stop3h 47m
Grand Junction Regnl
Fri 6/5
6:51 pm-11:34 pm
1 stop5h 43m
$271
OntarioGrand Junction
ONT - GJT
ONTGJT
Ontario
Wed 5/27
4:57 pm-10:00 pm
1 stop4h 03m
Grand Junction Regnl
Fri 6/5
6:51 pm-11:34 pm
1 stop5h 43m
$271
OntarioGrand Junction
ONT - GJT
ONTGJT
Ontario
Thu 5/28
4:57 pm-10:00 pm
1 stop4h 03m
Grand Junction Regnl
Sun 5/31
6:51 pm-11:34 pm
1 stop5h 43m
$271
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Tue 5/19
12:40 pm-6:20 pm
1 stop4h 40m
Denver Intl
Sat 5/23
1:15 pm-7:10 pm
2 stops6h 55m
$272
Showing 1-10 of 60 resultsSorted by cheapest first
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-COS
ONT-GJT
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-COS
ONT-GJT
ONT-DRO
What is the cheapest month to book a flight from Ontario to Colorado?
Currently, January is the cheapest month in which you can book a flight from Ontario to Colorado (average of $39). Flying from Ontario to Colorado in November is currently the most expensive (average of $85). 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 April 18, 2026.
It’s typically best to fly out from Ontario to Colorado in the evening. Doing so could potentially save you 52% 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 April 11, 2026.
Travelers seeking maximum savings on their Ontario to Colorado flight should consider departing on Monday evenings when fares are most often at their lowest. Monday 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 April 18, 2026.
The most flights from ONT to USCO are scheduled on a Friday (13 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (4 on average).
How much does it cost to fly round-trip from Ontario to Colorado?
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 April 18, 2026.
See what other customers who have flown with Southwest,Delta, andUnited 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.
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Overall
8.0
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Overall
8.0
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Overall
8.0
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Overall
8.0
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Overall
8.0
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Overall
8.0
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.
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Alternative routes for Ontario to Colorado
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Colorado by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Ontario to Colorado by cabin class
Find flights from Ontario to Colorado, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Ontario and Colorado flights
Browse other Ontario and Colorado flight options. Last updated on April 18, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Ontario to Colorado flights
Consider these flights traveling from Ontario to Colorado.
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 April 18, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$64 | Average$161 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$109 | Average$272 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$157 | Average$323 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$157 | Average$355 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$211 | Average$364 | FlexibilityNo cancel fee | On-time71% |