$63+ Cheap flights from Ontario (ONT) to Colorado
This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/13. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — DEN
Apr 5 — Apr 121
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 March 6, 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 March 6, 2026.
This CheapOair deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/136:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Thu 4/166:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/3![Frontier logo]()
$80
This Cheapflightsfares deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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 4/16:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Mon 4/610:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/4![Frontier logo]()
$81
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/76:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Tue 4/710:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$82
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/46:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Wed 4/810:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$83
This Cheapflightsfares deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/1612:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 4/196:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/3![Frontier logo]()
$84
This Super.com deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/116:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Wed 3/1110:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 3/3![Frontier logo]()
$86
This Kiwi.com deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” 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 4/2512:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Tue 4/2810:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/5![Frontier logo]()
$87
This Frontier deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/186:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Mon 3/2310:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 3/3![Frontier logo]()
$88
This Frontier deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/245:33 pm
ONT
- DEN
Nonstop2h 25m
Frontier
Mon 5/410:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/3![Frontier logo]()
$90
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/116:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Sun 4/196:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$91
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/56:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Tue 4/710:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$93
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/46:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Mon 4/1310:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$94
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 March 6, 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 March 6, 2026.
This Southwest deal was found by Cheapflights users on 3/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/163:00 pm
ONT
- DEN
Nonstop2h 15m
Southwest
Mon 4/209:15 pm
DEN
- ONT
Nonstop2h 25m
Southwest
Deal found 3/1![Southwest logo]()
$179
This Delta deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” 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
- DEN
1 stop4h 44m
Delta
Sat 5/306:19 pm
DEN
- ONT
1 stop5h 26m
Delta
Deal found 3/6![Delta logo]()
$221
This United Airlines deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” 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 3/5![United Airlines logo]()
$261
This American Airlines deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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 3/1912:19 pm
ONT
- GJT
1 stop5h 02m
American Airlines
Mon 3/2312:08 pm
GJT
- ONT
1 stop5h 14m
American Airlines
Deal found 3/4![American Airlines logo]()
$293
This Alaska Airlines deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/174:22 pm
ONT
- DEN
2 stops24h 02m
Alaska Airlines
Fri 4/246:00 am
DEN
- ONT
1 stop28h 45m
Alaska Airlines
Deal found 3/2![Alaska Airlines logo]()
$296
This Southwest deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/185:30 am
ONT
- DEN
2 stops5h 50m
Southwest
Mon 4/208:10 pm
DEN
- ONT
1 stop3h 55m
Southwest
Deal found 3/2![Southwest logo]()
$204
This Southwest deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/111:05 am
ONT
- MTJ
2 stops7h 50m
Southwest
Wed 4/88:45 am
MTJ
- ONT
1 stop7h 25m
Southwest
Deal found 3/3![Southwest logo]()
$216
This United Airlines deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/15:10 am
ONT
- COS
1 stop6h 26m
United Airlines
Sat 4/410:28 am
COS
- ONT
2 stops8h 19m
United Airlines
Deal found 3/5![United Airlines logo]()
$273
This Delta deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” 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 3/315:09 pm
ONT
- DEN
1 stop4h 22m
Delta
Thu 4/26:15 pm
DEN
- ONT
1 stop6h 36m
Delta
Deal found 3/6![Delta logo]()
$280
This United Airlines deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/236:49 pm
ONT
- DEN
1 stop4h 56m
United Airlines
Sun 4/267:10 pm
DEN
- ONT
Nonstop2h 26m
United Airlines
Deal found 3/4![United Airlines logo]()
$278
This Southwest deal was found by Cheapflights users on 3/6. Clicking the “Pick Dates” 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 5/1512:50 pm
ONT
- DEN
Nonstop2h 10m
Southwest
Sun 5/178:30 am
DEN
- ONT
Nonstop2h 20m
Southwest
Deal found 3/6![Southwest logo]()
$267
This American Airlines deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” 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 3/206:15 am
ONT
- DRO
1 stop3h 49m
American Airlines
Tue 3/2411:34 am
DRO
- ONT
1 stop5h 48m
American Airlines
Deal found 3/5![American Airlines logo]()
$325
This Alaska Airlines deal was found by Cheapflights users on 3/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/107:00 am
ONT
- DEN
1 stop10h 28m
Alaska Airlines
Tue 4/147:00 am
DEN
- ONT
2 stops11h 45m
Alaska Airlines
Deal found 3/1![Alaska Airlines logo]()
$330
This United Airlines deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/15:10 am
ONT
- MTJ
1 stop6h 31m
United Airlines
Sat 4/44:06 pm
MTJ
- ONT
1 stop7h 39m
United Airlines
Deal found 3/3![United Airlines logo]()
$281
This Delta deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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 3/235:09 pm
ONT
- DEN
1 stop4h 22m
Delta
Mon 3/306:15 pm
DEN
- ONT
1 stop6h 36m
Delta
Deal found 3/4![Delta logo]()
$318
This United Airlines deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/171:50 pm
ONT
- MTJ
1 stop5h 16m
United Airlines
Sat 3/214:04 pm
MTJ
- ONT
1 stop7h 53m
United Airlines
Deal found 3/2![United Airlines logo]()
$281
This Alaska Airlines deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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.
Mon 4/67:08 pm
ONT
- DEN
1 stop14h 43m
Alaska Airlines
Mon 4/136:20 pm
DEN
- ONT
2 stops22h 22m
Alaska Airlines
Deal found 3/4![Alaska Airlines logo]()
$366
This Delta deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:00 am
ONT
- COS
1 stop4h 12m
Delta
Thu 4/307:59 am
COS
- ONT
1 stop5h 15m
Delta
Deal found 3/5![Delta logo]()
$338
This United Airlines deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/241:43 pm
ONT
- DEN
Nonstop2h 20m
United Airlines
Fri 5/17:10 pm
DEN
- ONT
Nonstop2h 26m
United Airlines
Deal found 3/3![United Airlines logo]()
$287
This Southwest deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” 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 3/252:35 pm
ONT
- COS
1 stop5h 45m
Southwest
Sat 3/285:15 pm
COS
- ONT
2 stops7h 50m
Southwest
Deal found 3/5![Southwest logo]()
$328
This United Airlines deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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 6/41:18 pm
ONT
- MTJ
1 stop5h 52m
United Airlines
Tue 6/97:25 am
MTJ
- ONT
1 stop6h 22m
United Airlines
Deal found 3/4![United Airlines logo]()
$301
This KAYAK deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/316:15 am
ONT
- EGE
1 stop4h 39m
American Airlines
Sun 4/512:24 pm
EGE
- ONT
1 stop4h 58m
American Airlines
Deal found 3/5![American Airlines logo]()
$441
This Southwest deal was found by Cheapflights users on 3/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/317:05 am
ONT
- COS
1 stop4h 50m
Southwest
Fri 4/38:45 pm
COS
- ONT
1 stop3h 50m
Southwest
Deal found 3/1![Southwest logo]()
$356
This United Airlines deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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 3/195:15 am
ONT
- MTJ
1 stop6h 17m
United Airlines
Mon 3/233:39 pm
MTJ
- ONT
1 stop6h 11m
United Airlines
Deal found 3/4![United Airlines logo]()
$301
This Delta deal was found by Cheapflights users on 3/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/246:00 am
ONT
- COS
1 stop4h 12m
Delta
Sun 4/267:59 am
COS
- ONT
1 stop5h 15m
Delta
Deal found 3/1![Delta logo]()
$412
This Southwest deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/271:10 pm
ONT
- MTJ
1 stop5h 35m
Southwest
Tue 3/3112:35 pm
MTJ
- ONT
1 stop10h 45m
Southwest
Deal found 3/3![Southwest logo]()
$375
This United Airlines deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/16:49 pm
ONT
- DEN
1 stop4h 56m
United Airlines
Sun 4/57:10 pm
DEN
- ONT
Nonstop2h 26m
United Airlines
Deal found 3/4![United Airlines logo]()
$318
This Southwest deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/73:30 pm
ONT
- COS
2 stops7h 15m
Southwest
Mon 7/135:35 am
COS
- ONT
2 stops6h 45m
Southwest
Deal found 3/2![Southwest logo]()
$378
This United Airlines deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/75:00 am
ONT
- COS
1 stop4h 46m
United Airlines
Wed 7/155:07 pm
COS
- ONT
1 stop4h 35m
United Airlines
Deal found 3/3![United Airlines logo]()
$335
This Southwest deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/111:05 am
ONT
- MTJ
2 stops7h 50m
Southwest
Sat 4/411:00 am
MTJ
- ONT
2 stops7h 35m
Southwest
Deal found 3/3![Southwest logo]()
$380
Last-minute flights from Ontario to ColoradoDiscover last-minute flight deals from Ontario to Colorado. Data last updated March 6, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Colorado. Data last updated March 6, 2026 and is based on user searches.
This Super.com deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/116:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Wed 3/1110:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 3/3![Frontier logo]()
$86
This Frontier deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/186:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Mon 3/2310:29 pm
DEN
- ONT
Nonstop2h 30m
Frontier
Deal found 3/3![Frontier logo]()
$88
This Cheapflightsfares deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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 4/16:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Mon 4/610:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/4![Frontier logo]()
$81
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/46:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Wed 4/810:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$83
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/46:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Mon 4/1310:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$94
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/56:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Tue 4/710:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$93
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/76:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Tue 4/710:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$82
This Frontier deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/116:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Sun 4/196:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/2![Frontier logo]()
$91
This CheapOair deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/136:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Thu 4/166:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/3![Frontier logo]()
$80
This Cheapflightsfares deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/1612:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 4/196:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/3![Frontier logo]()
$84
This Frontier deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/2312:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Thu 4/3010:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/3![Frontier logo]()
$90
This Kiwi.com deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” 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 4/2512:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Tue 4/2810:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/5![Frontier logo]()
$87
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 March 6, 2026.
Search for one-way flight options from Ontario to Colorado. Find affordable one-way fares based on user searches. Data last updated March 6, 2026.
This Super.com deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/136:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Deal found 3/3![Frontier logo]()
$63
This Cheapflightsfares deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/56:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Deal found 3/3![Frontier logo]()
$64
This Kiwi.com deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/217:44 pm
ONT
- DEN
1 stop7h 15m
Frontier
Deal found 3/4![Frontier logo]()
$65
This Kiwi.com deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/147:44 pm
ONT
- DEN
1 stop14h 21m
Frontier
Deal found 3/4![Frontier logo]()
$66
This Kiwi.com deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/312:23 pm
ONT
- DEN
1 stop8h 56m
Frontier
Deal found 3/3![Frontier logo]()
$68
This Super.com deal was found by Cheapflights users on 3/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/136:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Deal found 3/2![Frontier logo]()
$69
This Super.com deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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 4/106:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Deal found 3/4![Frontier logo]()
$70
This Trip.com deal was found by Cheapflights users on 3/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/309:49 pm
ONT
- DEN
1 stop10h 12m
Frontier
Deal found 3/5![Frontier logo]()
$72
This Super.com deal was found by Cheapflights users on 3/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/212:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Deal found 3/3![Frontier logo]()
$73
This Expedia deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/1312:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Deal found 3/4![Frontier logo]()
$75
This United Airlines deal was found by Cheapflights users on 3/4. Clicking the “Pick Dates” 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 4/215:10 am
ONT
- COS
1 stop4h 55m
United Airlines
Deal found 3/4![United Airlines logo]()
$99
This Southwest deal was found by Cheapflights users on 3/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/204:30 pm
ONT
- COS
1 stop4h 50m
Southwest
Deal found 3/1![Southwest logo]()
$100
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 March 6, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $80 (CheapOair) |
One-way from | $63 (Super.com) |
Popular in | March |
Cheapest in | August |
Average price | $231 |
Good round-trip deal | $221 or less |
Good one-way deal | $126 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 March 6, 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
Thu 4/16
3:00 pm-6:15 pm
Nonstop2h 15m
Denver Intl
Mon 4/20
9:15 pm-10:40 pm
Nonstop2h 25m
$179
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 4/18
5:30 am-12:20 pm
2 stops5h 50m
Denver Intl
Mon 4/20
8:10 pm-11:05 pm
1 stop3h 55m
$204
OntarioMontrose
ONT - MTJ
ONTMTJ
Ontario
Wed 4/1
11:05 am-7:55 pm
2 stops7h 50m
Montrose County
Wed 4/8
8:45 am-3:10 pm
1 stop7h 25m
$216
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Thu 5/28
4:57 pm-10:41 pm
1 stop4h 44m
Denver Intl
Sat 5/30
6:19 pm-10:45 pm
1 stop5h 26m
$221
OntarioGrand Junction
ONT - GJT
ONTGJT
Ontario
Tue 5/5
5:00 am-10:43 am
1 stop4h 43m
Grand Junction Regnl
Sat 5/9
7:00 am-12:38 pm
1 stop6h 38m
$261
Quickest round-trip
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Fri 5/15
12:50 pm-4:00 pm
Nonstop2h 10m
Denver Intl
Sun 5/17
8:30 am-9:50 am
Nonstop2h 20m
$267
OntarioColorado Springs
ONT - COS
ONTCOS
Ontario
Wed 4/1
5:10 am-12:36 pm
1 stop6h 26m
Colorado Springs
Sat 4/4
10:28 am-5:47 pm
2 stops8h 19m
$273
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Thu 4/23
6:49 pm-12:45 am
1 stop4h 56m
Denver Intl
Sun 4/26
7:10 pm-8:36 pm
Nonstop2h 26m
$278
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Tue 3/31
5:09 pm-10:31 pm
1 stop4h 22m
Denver Intl
Thu 4/2
6:15 pm-11:51 pm
1 stop6h 36m
$280
OntarioMontrose
ONT - MTJ
ONTMTJ
Ontario
Wed 4/1
5:10 am-12:41 pm
1 stop6h 31m
Montrose County
Sat 4/4
4:06 pm-10:45 pm
1 stop7h 39m
$281
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-DRO
ONT-MTJ
ONT-GJT
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-DRO
ONT-MTJ
What is the cheapest month to book a flight from Ontario to Colorado?
Currently, March is the cheapest month in which you can book a flight from Ontario to Colorado (average of $38). Flying from Ontario to Colorado in September is currently the most expensive (average of $75). 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 March 6, 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 February 21, 2026.
Travelers seeking maximum savings on their Ontario to Colorado flight should consider departing on Tuesday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
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 March 6, 2026.
See what other customers who have flown with Southwest, Delta, and United Airlines from Ontario to Colorado have to say. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Crew
8.6
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Related info for your journey
Find useful and relevant information for your journey from Ontario to Colorado. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Browse thousands of different options on Cheapflights for your next trip
Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
Alternative routes
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 March 6, 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 March 6, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$62 | Average$158 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$109 | Average$265 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$124 | Average$313 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$130 | Average$359 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$211 | Average$357 | FlexibilityNo cancel fee | On-time71% |