$86+ 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 6/8. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — DEN
May 30 — Jun 61
Round-trip
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
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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 30, 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 30, 2026.
This Frontier deal was found by Cheapflights users on 4/26. 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.
Thu 5/1410:50 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/1910:29 pm
DEN
- ONT
Nonstop2h 20m
Frontier
Deal found 4/26![Frontier logo]()
$102
This Cheapflightsfares deal was found by Cheapflights users on 4/28. 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 5/236:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/268:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/28![Frontier logo]()
$106
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 5/213:30 pm
ONT
- DEN
1 stop7h 39m
Frontier
Wed 6/38:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/29![Frontier logo]()
$107
This Frontier deal was found by Cheapflights users on 4/28. 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 6/236:00 am
ONT
- DEN
Nonstop2h 26m
Frontier
Tue 6/3010:29 pm
DEN
- ONT
Nonstop2h 20m
Frontier
Deal found 4/28![Frontier logo]()
$108
This Cheapflightsfares deal was found by Cheapflights users on 4/27. 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 5/126:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/1910:33 am
DEN
- ONT
1 stop6h 11m
Frontier
Deal found 4/27![Frontier logo]()
$109
This Cheapflightsfares deal was found by Cheapflights users on 4/25. 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 5/156:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/198:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/25![Frontier logo]()
$111
This Super.com deal was found by Cheapflights users on 4/27. 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.
Sat 5/96:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Sun 5/108:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/27![Frontier logo]()
$112
This Super.com deal was found by Cheapflights users on 4/27. 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
Tue 5/1210:29 pm
DEN
- ONT
Nonstop2h 20m
Frontier
Deal found 4/27![Frontier logo]()
$113
This Frontier deal was found by Cheapflights users on 4/26. 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.
Thu 5/1410:50 am
ONT
- DEN
Nonstop2h 22m
Frontier
Wed 5/208:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/26![Frontier logo]()
$114
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 6/46:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Mon 6/810:33 am
DEN
- ONT
1 stop9h 59m
Frontier
Deal found 4/29![Frontier logo]()
$115
This Cheapflightsfares deal was found by Cheapflights users on 4/29. 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 5/299:52 am
DEN
- ONT
1 stop10h 19m
Frontier
Deal found 4/29![Frontier logo]()
$117
This Delta deal was found by Cheapflights users on 4/27. 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 6/16:00 am
ONT
- COS
1 stop4h 15m
Delta
Wed 6/38:15 am
COS
- ONT
1 stop5h 04m
Delta
Deal found 4/27![Delta logo]()
$197
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 30, 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 30, 2026.
This United Airlines deal was found by Cheapflights users on 4/25. 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 6/166:30 pm
ONT
- DEN
Nonstop2h 21m
United Airlines
Tue 6/234:05 pm
DEN
- ONT
Nonstop2h 23m
United Airlines
Deal found 4/25![United Airlines logo]()
$137
This Delta deal was found by Cheapflights users on 4/28. 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 6/46:00 am
ONT
- DEN
1 stop4h 45m
Delta
Mon 6/85:40 am
DEN
- ONT
1 stop4h 10m
Delta
Deal found 4/28![Delta logo]()
$197
This Southwest deal was found by Cheapflights users on 4/25. 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 5/165:40 am
ONT
- COS
1 stop5h 55m
Southwest
Tue 5/196:00 am
COS
- ONT
1 stop4h 50m
Southwest
Deal found 4/25![Southwest logo]()
$258
This Kiwi.com deal was found by Cheapflights users on 4/25. 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 5/1111:36 am
ONT
- GJT
1 stop23h 37m
Multiple Airlines
Fri 5/158:35 pm
GJT
- ONT
2 stops19h 34m
Multiple Airlines
Deal found 4/25![Multiple Airlines logo]()
$295
This Delta deal was found by Cheapflights users on 4/29. 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 5/231:29 pm
ONT
- DEN
1 stop4h 46m
Delta
Mon 5/255:30 am
DEN
- ONT
1 stop4h 23m
Delta
Deal found 4/29![Delta logo]()
$197
This American Airlines deal was found by Cheapflights users on 4/26. 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 5/116:15 am
ONT
- DRO
1 stop3h 56m
American Airlines
Fri 5/156:38 pm
DRO
- ONT
1 stop4h 21m
American Airlines
Deal found 4/26![American Airlines logo]()
$430
This United Airlines deal was found by Cheapflights users on 4/25. 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 6/46:30 pm
ONT
- DEN
Nonstop2h 21m
United Airlines
Mon 6/87:20 pm
DEN
- ONT
Nonstop2h 22m
United Airlines
Deal found 4/25![United Airlines logo]()
$258
This Southwest deal was found by Cheapflights users on 4/29. 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 5/264:30 pm
ONT
- DEN
1 stop4h 00m
Southwest
Tue 6/26:45 am
DEN
- ONT
2 stops5h 50m
Southwest
Deal found 4/29![Southwest logo]()
$282
This United Airlines deal was found by Cheapflights users on 4/29. 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 5/205:00 am
ONT
- DEN
Nonstop2h 22m
United Airlines
Tue 5/264:05 pm
DEN
- ONT
Nonstop2h 23m
United Airlines
Deal found 4/29![United Airlines logo]()
$277
This Delta deal was found by Cheapflights users on 4/28. 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 6/66:00 am
ONT
- COS
1 stop4h 15m
Delta
Wed 7/88:10 am
COS
- ONT
1 stop5h 00m
Delta
Deal found 4/28![Delta logo]()
$283
This Southwest deal was found by Cheapflights users on 4/29. 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 6/1610:10 am
ONT
- COS
2 stops5h 20m
Southwest
Tue 6/167:55 pm
COS
- ONT
1 stop4h 05m
Southwest
Deal found 4/29![Southwest logo]()
$288
This United Airlines deal was found by Cheapflights users on 4/29. 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 5/265:00 am
ONT
- DEN
Nonstop2h 20m
United Airlines
Tue 5/267:20 pm
DEN
- ONT
Nonstop2h 22m
United Airlines
Deal found 4/29![United Airlines logo]()
$277
This Delta deal was found by Cheapflights users on 4/28. 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.
Sun 5/176:00 am
ONT
- DEN
1 stop4h 45m
Delta
Thu 5/286:05 am
DEN
- ONT
1 stop7h 30m
Delta
Deal found 4/28![Delta logo]()
$287
This Delta deal was found by Cheapflights users on 4/26. 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 5/166:00 am
ONT
- COS
1 stop4h 15m
Delta
Sat 5/308:15 am
COS
- ONT
1 stop5h 04m
Delta
Deal found 4/26![Delta logo]()
$303
This Southwest deal was found by Cheapflights users on 4/26. 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.
Thu 7/168:45 pm
ONT
- COS
1 stop3h 35m
Southwest
Mon 7/209:05 pm
COS
- ONT
1 stop4h 00m
Southwest
Deal found 4/26![Southwest logo]()
$351
This United Airlines deal was found by Cheapflights users on 4/25. 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 5/161:40 pm
ONT
- MTJ
1 stop5h 38m
United Airlines
Wed 5/207:00 am
MTJ
- ONT
1 stop6h 38m
United Airlines
Deal found 4/25![United Airlines logo]()
$338
This Delta deal was found by Cheapflights users on 4/28. 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 5/199:50 am
ONT
- DEN
2 stops22h 08m
Delta
Wed 5/2712:35 pm
DEN
- ONT
1 stop4h 42m
Delta
Deal found 4/28![Delta logo]()
$311
This American Airlines deal was found by Cheapflights users on 4/29. 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.
Thu 7/910:25 am
ONT
- EGE
1 stop7h 25m
American Airlines
Thu 7/167:50 am
EGE
- ONT
1 stop6h 32m
American Airlines
Deal found 4/29![American Airlines logo]()
$459
This Southwest deal was found by Cheapflights users on 4/25. 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.
Thu 6/114:40 pm
ONT
- COS
2 stops7h 40m
Southwest
Sun 6/145:35 am
COS
- ONT
1 stop4h 45m
Southwest
Deal found 4/25![Southwest logo]()
$356
This United Airlines deal was found by Cheapflights users on 4/25. 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 5/95:00 am
ONT
- DRO
1 stop6h 33m
United Airlines
Tue 5/127:00 am
DRO
- ONT
1 stop6h 38m
United Airlines
Deal found 4/25![United Airlines logo]()
$340
This Southwest deal was found by Cheapflights users on 4/25. 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 5/255:30 am
ONT
- DEN
1 stop3h 40m
Southwest
Wed 5/276:45 am
DEN
- ONT
2 stops5h 50m
Southwest
Deal found 4/25![Southwest logo]()
$360
This Delta deal was found by Cheapflights users on 4/28. 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 6/66:00 am
ONT
- COS
1 stop4h 15m
Delta
Tue 7/78:10 am
COS
- ONT
1 stop5h 00m
Delta
Deal found 4/28![Delta logo]()
$338
This United Airlines deal was found by Cheapflights users on 4/27. 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 6/25:00 am
ONT
- MTJ
1 stop6h 44m
United Airlines
Wed 6/31:40 pm
MTJ
- ONT
1 stop4h 48m
United Airlines
Deal found 4/27![United Airlines logo]()
$355
This Southwest deal was found by Cheapflights users on 4/29. 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 5/1610:15 am
ONT
- DEN
2 stops5h 30m
Southwest
Mon 5/185:50 am
DEN
- ONT
1 stop3h 55m
Southwest
Deal found 4/29![Southwest logo]()
$362
This Delta deal was found by Cheapflights users on 4/26. 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 6/99:40 am
ONT
- COS
1 stop7h 00m
Delta
Wed 7/158:10 am
COS
- ONT
1 stop5h 00m
Delta
Deal found 4/26![Delta logo]()
$348
This United Airlines deal was found by Cheapflights users on 4/27. 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 5/265:00 am
ONT
- DRO
1 stop6h 28m
United Airlines
Tue 6/21:30 pm
DRO
- ONT
1 stop4h 58m
United Airlines
Deal found 4/27![United Airlines logo]()
$359
This Southwest deal was found by Cheapflights users on 4/27. 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 6/128:45 pm
ONT
- COS
1 stop3h 35m
Southwest
Mon 6/156:10 am
COS
- ONT
2 stops6h 10m
Southwest
Deal found 4/27![Southwest logo]()
$368
This Delta deal was found by Cheapflights users on 4/29. 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 5/211:29 pm
ONT
- DEN
1 stop4h 46m
Delta
Mon 5/255:30 am
DEN
- ONT
1 stop4h 23m
Delta
Deal found 4/29![Delta logo]()
$368
This Southwest deal was found by Cheapflights users on 4/25. 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 5/296:00 pm
ONT
- COS
1 stop5h 05m
Southwest
Sun 5/318:05 pm
COS
- ONT
1 stop5h 00m
Southwest
Deal found 4/25![Southwest logo]()
$375
This United Airlines deal was found by Cheapflights users on 4/28. 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 5/265:00 am
ONT
- DRO
1 stop6h 28m
United Airlines
Sat 5/304:45 pm
DRO
- ONT
1 stop4h 57m
United Airlines
Deal found 4/28![United Airlines logo]()
$398
Last-minute flights from Ontario to ColoradoDiscover last-minute flight deals from Ontario to Colorado. Data last updated April 30, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Colorado. Data last updated April 30, 2026 and is based on user searches.
This iWofly deal was found by Cheapflights users on 4/28. 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 iWofly is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/56:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Thu 5/78:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/28![Frontier logo]()
$115
This Super.com deal was found by Cheapflights users on 4/27. 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
Tue 5/1210:29 pm
DEN
- ONT
Nonstop2h 20m
Frontier
Deal found 4/27![Frontier logo]()
$113
This Super.com deal was found by Cheapflights users on 4/27. 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.
Sat 5/96:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Sun 5/108:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/27![Frontier logo]()
$112
This Cheapflightsfares deal was found by Cheapflights users on 4/27. 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 5/126:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/1910:33 am
DEN
- ONT
1 stop6h 11m
Frontier
Deal found 4/27![Frontier logo]()
$109
This Frontier deal was found by Cheapflights users on 4/26. 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.
Thu 5/1410:50 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/1910:29 pm
DEN
- ONT
Nonstop2h 20m
Frontier
Deal found 4/26![Frontier logo]()
$102
This Frontier deal was found by Cheapflights users on 4/26. 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.
Thu 5/1410:50 am
ONT
- DEN
Nonstop2h 22m
Frontier
Wed 5/208:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/26![Frontier logo]()
$114
This Cheapflightsfares deal was found by Cheapflights users on 4/25. 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 5/156:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/198:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/25![Frontier logo]()
$111
This Southwest deal was found by Cheapflights users on 4/25. 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 5/165:40 am
ONT
- COS
1 stop5h 55m
Southwest
Tue 5/196:00 am
COS
- ONT
1 stop4h 50m
Southwest
Deal found 4/25![Southwest logo]()
$258
This Kiwi.com deal was found by Cheapflights users on 4/29. 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 5/213:30 pm
ONT
- DEN
1 stop7h 39m
Frontier
Wed 6/38:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/29![Frontier logo]()
$107
This Cheapflightsfares deal was found by Cheapflights users on 4/28. 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 5/236:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Tue 5/268:41 am
DEN
- ONT
Nonstop2h 24m
Frontier
Deal found 4/28![Frontier logo]()
$106
This Frontier deal was found by Cheapflights users on 4/29. 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.
Mon 5/256:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Sat 5/306:05 am
DEN
- ONT
1 stop6h 01m
Frontier
Deal found 4/29![Frontier logo]()
$118
This Cheapflightsfares deal was found by Cheapflights users on 4/29. 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 5/299:52 am
DEN
- ONT
1 stop10h 19m
Frontier
Deal found 4/29![Frontier logo]()
$117
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 30, 2026.
Search for one-way flight options from Ontario to Colorado. Find affordable one-way fares based on user searches. Data last updated April 30, 2026.
This Super.com deal was found by Cheapflights users on 4/29. 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 6/86:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Deal found 4/29![Frontier logo]()
$86
This Super.com deal was found by Cheapflights users on 4/28. 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 5/298:59 am
ONT
- DEN
1 stop6h 44m
Frontier
Deal found 4/28![Frontier logo]()
$89
This Frontier deal was found by Cheapflights users on 4/28. 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 5/124:39 pm
ONT
- DEN
1 stop6h 30m
Frontier
Deal found 4/28![Frontier logo]()
$90
This Frontier deal was found by Cheapflights users on 4/29. 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 6/34:39 pm
ONT
- DEN
1 stop6h 30m
Frontier
Deal found 4/29![Frontier logo]()
$91
This Super.com deal was found by Cheapflights users on 4/29. 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.
Sat 5/166:00 am
ONT
- DEN
Nonstop2h 22m
Frontier
Deal found 4/29![Frontier logo]()
$93
This Super.com deal was found by Cheapflights users on 4/29. 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 6/161:33 pm
ONT
- DEN
1 stop7h 09m
Frontier
Deal found 4/29![Frontier logo]()
$94
This Super.com deal was found by Cheapflights users on 4/29. 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 5/288:06 pm
ONT
- DEN
1 stop26h 52m
Frontier
Deal found 4/29![Frontier logo]()
$95
This Cheapflightsfares deal was found by Cheapflights users on 4/29. 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 5/158:17 pm
ONT
- DEN
1 stop12h 35m
Frontier
Deal found 4/29![Frontier logo]()
$96
This Delta deal was found by Cheapflights users on 4/27. 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 5/194:57 pm
ONT
- COS
1 stop4h 25m
Delta
Deal found 4/27![Delta logo]()
$99
This Delta deal was found by Cheapflights users on 4/28. 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 7/16:00 am
ONT
- DEN
1 stop4h 53m
Delta
Deal found 4/28![Delta logo]()
$99
This Cheapflightsfares deal was found by Cheapflights users on 4/28. 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 7/221:28 pm
ONT
- DEN
1 stop10h 02m
Frontier
Deal found 4/28![Frontier logo]()
$100
This Kiwi.com deal was found by Cheapflights users on 4/26. 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 5/274:39 pm
ONT
- COS
2 stops46h 47m
Multiple Airlines
Deal found 4/26![Multiple Airlines logo]()
$116
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 30, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $102 (Frontier) |
One-way from | $86 (Super.com) |
Popular in | March |
Cheapest in | September |
Average price | $237 |
Good round-trip deal | $232 or less |
Good one-way deal | $134 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 30, 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
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Tue 6/16
6:30 pm-9:51 pm
Nonstop2h 21m
Denver Intl
Tue 6/23
4:05 pm-5:28 pm
Nonstop2h 23m
$137
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Thu 6/4
6:00 am-11:45 am
1 stop4h 45m
Denver Intl
Mon 6/8
5:40 am-8:50 am
1 stop4h 10m
$197
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 5/23
1:29 pm-7:15 pm
1 stop4h 46m
Denver Intl
Mon 5/25
5:30 am-8:53 am
1 stop4h 23m
$197
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Sat 5/16
5:40 am-12:35 pm
1 stop5h 55m
Colorado Springs
Tue 5/19
6:00 am-9:50 am
1 stop4h 50m
$258
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Thu 6/4
6:30 pm-9:51 pm
Nonstop2h 21m
Denver Intl
Mon 6/8
7:20 pm-8:42 pm
Nonstop2h 22m
$258
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Wed 5/20
5:00 am-8:22 am
Nonstop2h 22m
Denver Intl
Tue 5/26
4:05 pm-5:28 pm
Nonstop2h 23m
$277
Quickest round-trip
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Tue 5/26
5:00 am-8:20 am
Nonstop2h 20m
Denver Intl
Tue 5/26
7:20 pm-8:42 pm
Nonstop2h 22m
$277
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Tue 5/26
4:30 pm-9:30 pm
1 stop4h 00m
Denver Intl
Tue 6/2
6:45 am-11:35 am
2 stops5h 50m
$282
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Sat 6/6
6:00 am-11:15 am
1 stop4h 15m
Colorado Springs
Wed 7/8
8:10 am-12:10 pm
1 stop5h 00m
$283
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sun 5/17
6:00 am-11:45 am
1 stop4h 45m
Denver Intl
Thu 5/28
6:05 am-12:35 pm
1 stop7h 30m
$287
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
How far ahead should I book a flight from Ontario to Colorado?
The price you pay for your flight from Ontario to Colorado may vary depending on when you book. For the best chance of a lower fare, look to book 66 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
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 30, 2026.
It’s typically best to fly out from Ontario to Colorado in the evening. Doing so could potentially save you 51% 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 25, 2026.
Travelers seeking maximum savings on their Ontario to Colorado flight should consider departing on Friday afternoons 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 April 30, 2026.
The most flights from ONT to USCO are scheduled on a Monday (11 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (2 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 30, 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.
Food
7.0
Comfort
8.0
Crew
8.6
Overall
8.0
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Comfort
8.0
Crew
8.6
Overall
8.0
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Comfort
8.0
Crew
8.6
Overall
8.0
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Comfort
8.0
Crew
8.6
Overall
8.0
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Comfort
8.0
Crew
8.6
Overall
8.0
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Comfort
8.0
Crew
8.6
Overall
8.0
Boarding
8.1
Entertainment
7.5
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.
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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 30, 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 30, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$63 | Average$162 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$157 | Average$364 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$157 | Average$327 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$172 | Average$300 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$211 | Average$364 | FlexibilityNo cancel fee | On-time71% |