$89+ 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 7/25. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — DEN
Jul 29 — Aug 51
Round-trip
1 adult, Economy
We work with more than 300 partners to bring you better travel deals
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
Cheapest
Best
Last-minute
One-way
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 June 29, 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 June 29, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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 9/176:00 am
ONT
- DEN
Nonstop2h 26m
Frontier
Mon 9/2110:34 pm
DEN
- ONT
Nonstop2h 21m
Frontier
Deal found 6/24![Frontier logo]()
$127
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 11/122:35 pm
ONT
- DEN
Nonstop2h 22m
Frontier
Sat 11/1412:15 pm
DEN
- ONT
Nonstop2h 25m
Frontier
Deal found 6/24![Frontier logo]()
$128
This Frontier deal was found by Cheapflights users on 6/25. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/152:55 pm
ONT
- DEN
Nonstop2h 22m
Frontier
Thu 10/1510:34 pm
DEN
- ONT
Nonstop2h 21m
Frontier
Deal found 6/25![Frontier logo]()
$129
This Kiwi.com deal was found by Cheapflights users on 6/26. 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.
Sat 9/266:00 am
ONT
- DEN
Nonstop2h 26m
Frontier
Tue 9/2912:32 pm
DEN
- ONT
Nonstop2h 25m
Frontier
Deal found 6/26![Frontier logo]()
$130
This Super.com deal was found by Cheapflights users on 6/24. 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 7/226:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 7/258:45 am
DEN
- ONT
Nonstop2h 19m
Frontier
Deal found 6/24![Frontier logo]()
$141
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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 10/292:35 pm
ONT
- DEN
Nonstop2h 22m
Frontier
Mon 11/29:15 am
DEN
- ONT
Nonstop2h 28m
Frontier
Deal found 6/24![Frontier logo]()
$142
This Booking.com deal was found by Cheapflights users on 6/25. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/216:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Tue 7/2110:29 pm
DEN
- ONT
Nonstop2h 21m
Frontier
Deal found 6/25![Frontier logo]()
$144
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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 8/810:49 am
ONT
- DEN
Nonstop2h 21m
Frontier
Wed 8/1210:00 am
DEN
- ONT
1 stop23h 03m
Frontier
Deal found 6/24![Frontier logo]()
$147
This Super.com deal was found by Cheapflights users on 6/24. 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 7/146:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 7/188:45 am
DEN
- ONT
Nonstop2h 19m
Frontier
Deal found 6/24![Frontier logo]()
$148
This Frontier deal was found by Cheapflights users on 6/24. 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 8/116:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Wed 8/129:06 pm
DEN
- ONT
1 stop11h 26m
Frontier
Deal found 6/24![Frontier logo]()
$149
This Kiwi.com deal was found by Cheapflights users on 6/26. 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 9/239:49 pm
ONT
- DEN
1 stop5h 03m
Frontier
Tue 9/2912:32 pm
DEN
- ONT
Nonstop2h 25m
Frontier
Deal found 6/26![Frontier logo]()
$153
This Southwest deal was found by Cheapflights users on 6/28. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/284:35 pm
ONT
- COS
1 stop5h 25m
Southwest
Wed 8/56:55 am
COS
- ONT
1 stop4h 30m
Southwest
Deal found 6/28![Southwest 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 June 29, 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 June 29, 2026.
This Southwest deal was found by Cheapflights users on 6/25. 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.
Wed 10/75:30 am
ONT
- DEN
2 stops6h 05m
Southwest
Sat 10/108:45 am
DEN
- ONT
Nonstop2h 20m
Southwest
Deal found 6/25![Southwest logo]()
$192
This Delta deal was found by Cheapflights users on 6/25. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/155:05 pm
ONT
- COS
1 stop4h 23m
Delta
Sat 8/226:16 pm
COS
- ONT
1 stop5h 07m
Delta
Deal found 6/25![Delta logo]()
$197
This United Airlines deal was found by Cheapflights users on 6/28. 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.
Sat 8/15:00 am
ONT
- DEN
Nonstop2h 20m
United Airlines
Sat 8/87:20 pm
DEN
- ONT
Nonstop2h 22m
United Airlines
Deal found 6/28![United Airlines logo]()
$257
This Southwest deal was found by Cheapflights users on 6/26. 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.
Wed 8/121:50 pm
ONT
- COS
1 stop6h 55m
Southwest
Wed 8/197:20 am
COS
- ONT
1 stop3h 55m
Southwest
Deal found 6/26![Southwest logo]()
$197
This Delta deal was found by Cheapflights users on 6/23. 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 8/16:00 am
ONT
- DEN
1 stop4h 47m
Delta
Wed 8/56:28 pm
DEN
- ONT
1 stop6h 06m
Delta
Deal found 6/23![Delta logo]()
$197
This Delta deal was found by Cheapflights users on 6/25. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/151:06 pm
ONT
- DEN
1 stop5h 55m
Delta
Tue 8/185:35 am
DEN
- ONT
1 stop4h 17m
Delta
Deal found 6/25![Delta logo]()
$197
This Southwest deal was found by Cheapflights users on 6/24. 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.
Wed 8/192:10 pm
ONT
- DEN
2 stops6h 10m
Southwest
Sat 8/229:10 am
DEN
- ONT
2 stops7h 05m
Southwest
Deal found 6/24![Southwest logo]()
$207
This American Airlines deal was found by Cheapflights users on 6/24. 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 8/314:07 pm
ONT
- DRO
1 stop4h 07m
American Airlines
Wed 9/94:47 pm
DRO
- ONT
1 stop6h 50m
American Airlines
Deal found 6/24![American Airlines logo]()
$467
This Delta deal was found by Cheapflights users on 6/28. 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 9/21:06 pm
ONT
- DEN
1 stop5h 55m
Delta
Wed 9/97:05 am
DEN
- ONT
1 stop6h 09m
Delta
Deal found 6/28![Delta logo]()
$197
This Delta deal was found by Cheapflights users on 6/24. 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 8/81:06 pm
ONT
- DEN
1 stop5h 55m
Delta
Mon 8/105:35 am
DEN
- ONT
1 stop4h 17m
Delta
Deal found 6/24![Delta logo]()
$210
This United Airlines deal was found by Cheapflights users on 6/25. 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 8/295:00 am
ONT
- MTJ
1 stop6h 45m
United Airlines
Wed 9/23:24 pm
MTJ
- ONT
1 stop6h 29m
United Airlines
Deal found 6/25![United Airlines logo]()
$317
This Delta deal was found by Cheapflights users on 6/25. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/155:05 pm
ONT
- COS
1 stop4h 23m
Delta
Tue 8/186:16 pm
COS
- ONT
1 stop6h 18m
Delta
Deal found 6/25![Delta logo]()
$238
This United Airlines deal was found by Cheapflights users on 6/23. 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 11/175:00 am
ONT
- MTJ
1 stop6h 34m
United Airlines
Wed 11/181:35 pm
MTJ
- ONT
2 stops10h 18m
United Airlines
Deal found 6/23![United Airlines logo]()
$322
This United Airlines deal was found by Cheapflights users on 6/24. 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 8/225:00 am
ONT
- MTJ
1 stop6h 45m
United Airlines
Thu 8/273:24 pm
MTJ
- ONT
1 stop6h 29m
United Airlines
Deal found 6/24![United Airlines logo]()
$334
This Southwest deal was found by Cheapflights users on 6/24. 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 7/245:30 am
ONT
- DEN
2 stops5h 55m
Southwest
Sat 7/257:50 am
DEN
- ONT
1 stop6h 50m
Southwest
Deal found 6/24![Southwest logo]()
$349
This United Airlines deal was found by Cheapflights users on 6/28. 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.
Sat 7/255:00 am
ONT
- DEN
Nonstop2h 20m
United Airlines
Tue 7/287:20 pm
DEN
- ONT
Nonstop2h 22m
United Airlines
Deal found 6/28![United Airlines logo]()
$348
This Southwest deal was found by Cheapflights users on 6/24. 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 9/34:10 pm
ONT
- DEN
1 stop5h 55m
Southwest
Mon 9/74:10 pm
DEN
- ONT
2 stops6h 15m
Southwest
Deal found 6/24![Southwest logo]()
$362
This Delta deal was found by Cheapflights users on 6/26. 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.
Thu 8/135:05 pm
ONT
- GJT
1 stop3h 51m
Delta
Tue 8/187:41 am
GJT
- ONT
1 stop5h 35m
Delta
Deal found 6/26![Delta logo]()
$319
This United Airlines deal was found by Cheapflights users on 6/25. 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.
Sun 8/165:00 am
ONT
- MTJ
1 stop6h 45m
United Airlines
Sat 8/221:42 pm
MTJ
- ONT
2 stops7h 19m
United Airlines
Deal found 6/25![United Airlines logo]()
$353
This Southwest deal was found by Cheapflights users on 6/25. 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 7/204:40 pm
ONT
- COS
2 stops7h 45m
Southwest
Wed 7/226:00 am
COS
- ONT
1 stop4h 05m
Southwest
Deal found 6/25![Southwest logo]()
$368
This American Airlines deal was found by Cheapflights users on 6/26. 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 8/3112:33 pm
ONT
- ASE
1 stop6h 43m
American Airlines
Thu 9/310:31 am
ASE
- ONT
2 stops8h 44m
American Airlines
Deal found 6/26![American Airlines logo]()
$546
This Delta deal was found by Cheapflights users on 6/25. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/305:05 pm
ONT
- GJT
1 stop3h 51m
Delta
Sat 9/57:41 am
GJT
- ONT
1 stop5h 35m
Delta
Deal found 6/25![Delta logo]()
$319
This United Airlines deal was found by Cheapflights users on 6/26. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/111:50 pm
ONT
- GJT
2 stops7h 21m
United Airlines
Wed 7/157:00 am
GJT
- ONT
1 stop6h 47m
United Airlines
Deal found 6/26![United Airlines logo]()
$354
This Southwest deal was found by Cheapflights users on 6/26. 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.
Tue 8/1810:55 am
ONT
- COS
1 stop4h 05m
Southwest
Fri 8/2112:20 pm
COS
- ONT
2 stops6h 40m
Southwest
Deal found 6/26![Southwest logo]()
$372
This United Airlines deal was found by Cheapflights users on 6/26. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/205:00 am
ONT
- MTJ
1 stop6h 35m
United Airlines
Wed 10/217:15 am
MTJ
- ONT
1 stop6h 31m
United Airlines
Deal found 6/26![United Airlines logo]()
$357
This Southwest deal was found by Cheapflights users on 6/25. 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.
Tue 7/145:30 am
ONT
- DEN
2 stops6h 05m
Southwest
Tue 7/216:00 am
DEN
- ONT
1 stop6h 30m
Southwest
Deal found 6/25![Southwest logo]()
$383
This Delta deal was found by Cheapflights users on 6/24. 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 8/315:05 pm
ONT
- GJT
1 stop3h 51m
Delta
Sat 9/57:41 am
GJT
- ONT
1 stop5h 35m
Delta
Deal found 6/24![Delta logo]()
$359
This United Airlines deal was found by Cheapflights users on 6/27. 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.
Thu 8/205:00 am
ONT
- DRO
1 stop6h 32m
United Airlines
Sun 8/235:15 am
DRO
- ONT
2 stops7h 57m
United Airlines
Deal found 6/27![United Airlines logo]()
$387
This Southwest deal was found by Cheapflights users on 6/26. 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.
Mon 7/202:30 pm
ONT
- COS
1 stop6h 20m
Southwest
Thu 7/234:55 pm
COS
- ONT
1 stop6h 45m
Southwest
Deal found 6/26![Southwest logo]()
$413
This Delta deal was found by Cheapflights users on 6/27. 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 8/255:05 pm
ONT
- GJT
1 stop3h 51m
Delta
Mon 8/316:53 pm
GJT
- ONT
1 stop4h 30m
Delta
Deal found 6/27![Delta logo]()
$379
Last-minute flights from Ontario to ColoradoDiscover last-minute flight deals from Ontario to Colorado. Data last updated June 29, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Colorado. Data last updated June 29, 2026 and is based on user searches.
This Super.com deal was found by Cheapflights users on 6/24. 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 7/146:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 7/188:45 am
DEN
- ONT
Nonstop2h 19m
Frontier
Deal found 6/24![Frontier logo]()
$148
This Kiwi.com deal was found by Cheapflights users on 6/25. 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.
Wed 7/1510:49 am
ONT
- DEN
Nonstop2h 21m
Frontier
Wed 8/1210:00 am
DEN
- ONT
1 stop6h 14m
Frontier
Deal found 6/25![Frontier logo]()
$153
This Booking.com deal was found by Cheapflights users on 6/25. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/216:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Tue 7/2110:29 pm
DEN
- ONT
Nonstop2h 21m
Frontier
Deal found 6/25![Frontier logo]()
$144
This Frontier deal was found by Cheapflights users on 6/24. 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 7/218:17 am
ONT
- DEN
1 stop13h 38m
Frontier
Wed 7/2910:29 pm
DEN
- ONT
Nonstop2h 21m
Frontier
Deal found 6/24![Frontier logo]()
$159
This Delta deal was found by Cheapflights users on 6/27. 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 7/215:10 pm
ONT
- COS
1 stop4h 31m
Delta
Tue 7/286:16 pm
COS
- ONT
1 stop6h 32m
Delta
Deal found 6/27![Delta logo]()
$238
This Super.com deal was found by Cheapflights users on 6/24. 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 7/226:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 7/258:45 am
DEN
- ONT
Nonstop2h 19m
Frontier
Deal found 6/24![Frontier logo]()
$141
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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 7/256:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Wed 7/299:06 pm
DEN
- ONT
1 stop11h 26m
Frontier
Deal found 6/24![Frontier logo]()
$157
This Super.com deal was found by Cheapflights users on 6/26. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/256:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Sat 7/2510:29 pm
DEN
- ONT
Nonstop2h 21m
Frontier
Deal found 6/26![Frontier logo]()
$165
This Cheapflightsfares deal was found by Cheapflights users on 6/28. 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 7/256:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Tue 7/288:45 am
DEN
- ONT
Nonstop2h 19m
Frontier
Deal found 6/28![Frontier logo]()
$166
This Frontier deal was found by Cheapflights users on 6/25. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/286:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Tue 8/410:00 am
DEN
- ONT
1 stop6h 14m
Frontier
Deal found 6/25![Frontier logo]()
$149
This Southwest deal was found by Cheapflights users on 6/28. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/284:35 pm
ONT
- COS
1 stop5h 25m
Southwest
Wed 8/56:55 am
COS
- ONT
1 stop4h 30m
Southwest
Deal found 6/28![Southwest logo]()
$197
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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 7/296:00 am
ONT
- DEN
Nonstop2h 24m
Frontier
Tue 8/410:29 pm
DEN
- ONT
1 stop15h 19m
Frontier
Deal found 6/24![Frontier logo]()
$147
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 June 29, 2026.
Search for one-way flight options from Ontario to Colorado. Find affordable one-way fares based on user searches. Data last updated June 29, 2026.
This United Airlines deal was found by Cheapflights users on 6/26. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/255:00 am
ONT
- DEN
Nonstop2h 20m
United Airlines
Deal found 6/26![United Airlines logo]()
$89
This American Airlines deal was found by Cheapflights users on 6/25. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/156:15 am
ONT
- DEN
1 stop4h 12m
American Airlines
Deal found 6/25![American Airlines logo]()
$98
This Southwest deal was found by Cheapflights users on 6/25. 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.
Wed 7/156:35 pm
ONT
- COS
1 stop4h 15m
Southwest
Deal found 6/25![Southwest logo]()
$99
This Southwest deal was found by Cheapflights users on 6/24. 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.
Wed 7/224:10 pm
ONT
- DEN
1 stop6h 10m
Southwest
Deal found 6/24![Southwest logo]()
$99
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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 8/51:38 pm
ONT
- DEN
1 stop7h 03m
Frontier
Deal found 6/24![Frontier logo]()
$103
This Southwest deal was found by Cheapflights users on 6/25. 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.
Tue 7/214:10 pm
ONT
- DEN
2 stops6h 00m
Southwest
Deal found 6/25![Southwest logo]()
$104
This Frontier deal was found by Cheapflights users on 6/25. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/34:27 pm
ONT
- DEN
1 stop6h 48m
Frontier
Deal found 6/25![Frontier logo]()
$105
This Southwest deal was found by Cheapflights users on 6/24. 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 11/96:50 pm
ONT
- DEN
1 stop3h 35m
Southwest
Deal found 6/24![Southwest logo]()
$107
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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 10/1311:16 am
ONT
- DEN
1 stop11h 59m
Frontier
Deal found 6/24![Frontier logo]()
$109
This Frontier deal was found by Cheapflights users on 6/24. 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 8/199:37 am
ONT
- DEN
1 stop9h 59m
Frontier
Deal found 6/24![Frontier logo]()
$111
This Delta deal was found by Cheapflights users on 6/25. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/201:06 pm
ONT
- DEN
1 stop5h 55m
Delta
Deal found 6/25![Delta logo]()
$112
This Super.com deal was found by Cheapflights users on 6/24. 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 7/291:38 pm
ONT
- DEN
1 stop7h 03m
Frontier
Deal found 6/24![Frontier logo]()
$113
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 June 29, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $127 (Cheapflightsfares) |
One-way from | $89 (United Airlines) |
Popular in | June |
Cheapest in | September |
Average price | $277 |
Good round-trip deal | $303 or less |
Good one-way deal | $192 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 June 29, 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
Wed 10/7
5:30 am-12:35 pm
2 stops6h 05m
Denver Intl
Sat 10/10
8:45 am-10:05 am
Nonstop2h 20m
$192
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Sat 8/15
5:05 pm-10:28 pm
1 stop4h 23m
Colorado Springs
Sat 8/22
6:16 pm-10:23 pm
1 stop5h 07m
$197
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Wed 8/12
1:50 pm-9:45 pm
1 stop6h 55m
Colorado Springs
Wed 8/19
7:20 am-10:15 am
1 stop3h 55m
$197
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 8/1
6:00 am-11:47 am
1 stop4h 47m
Denver Intl
Wed 8/5
6:28 pm-11:34 pm
1 stop6h 06m
$197
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 8/15
1:06 pm-8:01 pm
1 stop5h 55m
Denver Intl
Tue 8/18
5:35 am-8:52 am
1 stop4h 17m
$197
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Wed 9/2
1:06 pm-8:01 pm
1 stop5h 55m
Denver Intl
Wed 9/9
7:05 am-12:14 pm
1 stop6h 09m
$197
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Wed 8/19
2:10 pm-9:20 pm
2 stops6h 10m
Denver Intl
Sat 8/22
9:10 am-3:15 pm
2 stops7h 05m
$207
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 8/8
1:06 pm-8:01 pm
1 stop5h 55m
Denver Intl
Mon 8/10
5:35 am-8:52 am
1 stop4h 17m
$210
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Sat 8/15
5:05 pm-10:28 pm
1 stop4h 23m
Colorado Springs
Tue 8/18
6:16 pm-11:34 pm
1 stop6h 18m
$238
Quickest round-trip
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 8/1
5:00 am-8:20 am
Nonstop2h 20m
Denver Intl
Sat 8/8
7:20 pm-8:42 pm
Nonstop2h 22m
$257
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-MTJ
ONT-GJT
ONT-ASE
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-MTJ
ONT-GJT
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 June 29, 2026.
It’s typically best to fly out from Ontario to Colorado in the evening. Doing so could potentially save you 54% on the flight price compared to flying at noon, which is usually more expensive.
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 June 29, 2026.
The most flights from ONT to USCO are scheduled on a Monday (14 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (5 on average).
How much does it cost to fly round-trip from Ontario to Colorado?
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 68 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
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 June 27, 2026.
Travelers seeking maximum savings on their Ontario to Colorado flight should consider departing on Tuesday afternoons 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.
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 June 29, 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
Crew
8.6
Boarding
8.1
Comfort
8.0
Food
7.0
Overall
7.9
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Food
7.0
Overall
7.9
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Food
7.0
Overall
7.9
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Food
7.0
Overall
7.9
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Food
7.0
Overall
7.9
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Food
7.0
Overall
7.9
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
Complete your trip
Flights by cabin class
Other flight options
Popular flights
Top destinations
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 June 29, 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 June 29, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$61 | Average$170 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$157 | Average$364 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$157 | Average$368 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$172 | Average$273 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$211 | Average$340 | FlexibilityNo cancel fee | On-time71% |