$33+ 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 10/1. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — DEN
Sep 25 — Oct 21
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
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Ontario to Colorado
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Cheapest flights from Ontario to ColoradoExplore the most affordable flight options available from Ontario to Colorado. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 26, 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 August 26, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 8/25. 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.
Mon 9/146:15 am -
Nonstop2h 20m
Thu 9/179:05 am -
Nonstop2h 25m
Deal found 8/25![Frontier logo]()
$101
This Cheapflightsfares deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 10/211:45 am -
Nonstop2h 22m
Mon 10/510:29 pm -
Nonstop2h 18m
Deal found 8/21![Frontier logo]()
$104
This Cheapflightsfares deal was found by Cheapflights users on 8/26. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/1811:45 am -
Nonstop2h 22m
Tue 9/2210:29 pm -
Nonstop2h 18m
Deal found 8/26![Frontier logo]()
$105
This Cheapflightsfares deal was found by Cheapflights users on 8/23. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/1211:45 am -
Nonstop2h 22m
Mon 9/149:43 am -
1 stop24h 26m
Deal found 8/23![Frontier logo]()
$106
This Cheapflightsfares deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 9/2411:45 am -
Nonstop2h 22m
Mon 9/2810:29 pm -
Nonstop2h 18m
Deal found 8/21![Frontier logo]()
$108
This Cheapflightsfares deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 9/1111:45 am -
Nonstop2h 22m
Mon 9/149:05 am -
Nonstop2h 25m
Deal found 8/21![Frontier logo]()
$109
This Cheapflightsfares deal was found by Cheapflights users on 8/25. 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.
Thu 9/176:45 pm -
1 stop16h 25m
Thu 9/249:05 am -
Nonstop2h 25m
Deal found 8/25![Frontier logo]()
$111
This Expedia deal was found by Cheapflights users on 8/26. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2211:45 am -
Nonstop2h 22m
Mon 10/56:38 pm -
1 stop15h 31m
Deal found 8/26![Frontier logo]()
$112
This Booking.com deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 9/225:44 pm -
1 stop5h 00m
Sat 9/269:05 am -
Nonstop2h 25m
Deal found 8/22![Frontier logo]()
$113
This Mytrip deal was found by Cheapflights users on 8/23. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/2311:45 am -
Nonstop2h 22m
Wed 9/301:05 pm -
1 stop4h 54m
Deal found 8/23![Frontier logo]()
$114
This American Airlines deal was found by Cheapflights users on 8/24. 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.
Tue 9/221:04 pm -
1 stop4h 18m
Tue 9/298:20 am -
1 stop4h 46m
Deal found 8/24![American Airlines logo]()
$319
This United Airlines deal was found by Cheapflights users on 8/24. 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 11/145:00 am -
1 stop6h 36m
Tue 11/177:15 am -
1 stop6h 18m
Deal found 8/24![United Airlines logo]()
$323
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 August 26, 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 August 26, 2026.
This Delta deal was found by Cheapflights users on 8/24. 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.
Wed 9/169:52 am -
1 stop6h 10m
Tue 9/2910:45 am -
1 stop6h 50m
Deal found 8/24![Delta logo]()
$197
This United Airlines deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 1/115:00 am -
Nonstop2h 11m
Sat 1/237:05 pm -
Nonstop2h 15m
Deal found 8/21![United Airlines logo]()
$237
This Southwest deal was found by Cheapflights users on 8/25. 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 10/55:30 am -
2 stops5h 25m
Thu 10/85:55 am -
1 stop6h 30m
Deal found 8/25![Southwest logo]()
$283
This Delta deal was found by Cheapflights users on 8/25. 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 10/101:35 pm -
1 stop4h 59m
Mon 10/195:25 am -
1 stop4h 30m
Deal found 8/25![Delta logo]()
$226
This United Airlines deal was found by Cheapflights users on 8/25. 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.
Wed 9/231:18 pm -
Nonstop2h 21m
Wed 9/307:35 pm -
Nonstop2h 23m
Deal found 8/25![United Airlines logo]()
$237
This United Airlines deal was found by Cheapflights users on 8/24. 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.
Thu 1/75:00 am -
Nonstop2h 11m
Mon 1/115:15 am -
1 stop8h 05m
Deal found 8/24![United Airlines logo]()
$277
This Delta deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 9/96:00 am -
1 stop5h 09m
Mon 9/145:30 am -
1 stop4h 32m
Deal found 8/22![Delta logo]()
$283
This Southwest deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 10/78:25 am -
2 stops5h 50m
Thu 10/82:55 pm -
2 stops6h 25m
Deal found 8/22![Southwest logo]()
$334
This Delta deal was found by Cheapflights users on 8/25. 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.
Mon 11/231:15 pm -
1 stop6h 14m
Thu 11/2612:53 pm -
1 stop6h 37m
Deal found 8/25![Delta logo]()
$288
This Southwest deal was found by Cheapflights users on 8/23. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/103:10 pm -
1 stop6h 05m
Wed 10/215:45 pm -
1 stop4h 35m
Deal found 8/23![Southwest logo]()
$351
This United Airlines deal was found by Cheapflights users on 8/24. 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 11/145:00 am -
1 stop6h 36m
Tue 11/177:15 am -
1 stop6h 18m
Deal found 8/24![United Airlines logo]()
$323
This Delta deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 9/125:15 pm -
1 stop3h 42m
Mon 9/147:41 am -
1 stop5h 33m
Deal found 8/21![Delta logo]()
$319
This Southwest deal was found by Cheapflights users on 8/23. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/201:35 pm -
2 stops7h 05m
Tue 11/106:55 am -
2 stops6h 00m
Deal found 8/23![Southwest logo]()
$361
This United Airlines deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 9/101:18 pm -
1 stop6h 17m
Tue 9/157:00 am -
2 stops8h 01m
Deal found 8/22![United Airlines logo]()
$339
This Southwest deal was found by Cheapflights users on 8/26. 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.
Fri 9/112:00 pm -
Nonstop2h 15m
Sun 9/138:45 am -
Nonstop2h 15m
Deal found 8/26![Southwest logo]()
$369
This Delta deal was found by Cheapflights users on 8/25. 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 9/265:15 pm -
1 stop3h 42m
Sun 9/277:41 am -
1 stop5h 33m
Deal found 8/25![Delta logo]()
$364
This United Airlines deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 9/241:24 pm -
1 stop6h 14m
Sat 10/33:24 pm -
1 stop6h 34m
Deal found 8/22![United Airlines logo]()
$388
This Southwest deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 9/55:50 am -
1 stop5h 20m
Sat 9/52:00 pm -
1 stop4h 25m
Deal found 8/21![Southwest logo]()
$391
This Delta deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 9/76:00 am -
1 stop5h 09m
Sun 9/135:30 am -
1 stop4h 32m
Deal found 8/22![Delta logo]()
$369
This United Airlines deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 11/131:29 pm -
1 stop6h 07m
Tue 11/173:20 pm -
1 stop6h 31m
Deal found 8/21![United Airlines logo]()
$388
This Delta deal was found by Cheapflights users on 8/23. 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.
Fri 10/169:45 am -
1 stop6h 42m
Mon 10/198:17 am -
1 stop5h 19m
Deal found 8/23![Delta logo]()
$372
This Southwest deal was found by Cheapflights users on 8/25. 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 12/224:25 pm -
2 stops7h 15m
Mon 12/285:55 am -
1 stop3h 55m
Deal found 8/25![Southwest logo]()
$419
This United Airlines deal was found by Cheapflights users on 8/25. 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 12/225:00 am -
1 stop6h 56m
Mon 12/285:06 pm -
1 stop4h 54m
Deal found 8/25![United Airlines logo]()
$403
This Delta deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 9/245:15 pm -
1 stop4h 10m
Tue 9/296:11 pm -
1 stop6h 36m
Deal found 8/22![Delta logo]()
$394
This United Airlines deal was found by Cheapflights users on 8/23. 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.
Fri 9/115:00 am -
1 stop6h 32m
Sat 9/197:00 am -
1 stop6h 50m
Deal found 8/23![United Airlines logo]()
$403
This United Airlines deal was found by Cheapflights users on 8/24. 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.
Wed 11/41:29 pm -
1 stop7h 30m
Sat 11/75:30 am -
2 stops7h 59m
Deal found 8/24![United Airlines logo]()
$404
This United Airlines deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 9/101:18 pm -
1 stop6h 36m
Sat 9/1911:26 am -
2 stops9h 35m
Deal found 8/21![United Airlines logo]()
$409
This United Airlines deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 9/235:00 am -
1 stop6h 28m
Sat 9/265:07 pm -
1 stop4h 51m
Deal found 8/22![United Airlines logo]()
$431
This United Airlines deal was found by Cheapflights users on 8/25. 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 10/101:52 pm -
2 stops7h 14m
Wed 10/215:08 pm -
1 stop4h 50m
Deal found 8/25![United Airlines logo]()
$436
This United Airlines deal was found by Cheapflights users on 8/23. 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.
Wed 9/231:56 pm -
2 stops8h 59m
Wed 10/78:38 am -
1 stop5h 08m
Deal found 8/23![United Airlines logo]()
$436
Last-minute flights from Ontario to ColoradoDiscover last-minute flight deals from Ontario to Colorado. Data last updated August 26, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Colorado. Data last updated August 26, 2026 and is based on user searches.
This Delta deal was found by Cheapflights users on 8/24. 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.
Thu 9/101:04 pm -
1 stop4h 14m
Tue 9/227:41 am -
1 stop5h 33m
Deal found 8/24![Delta logo]()
$334
This Cheapflightsfares deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 9/1111:45 am -
Nonstop2h 22m
Mon 9/149:05 am -
Nonstop2h 25m
Deal found 8/21![Frontier logo]()
$109
This Cheapflightsfares deal was found by Cheapflights users on 8/23. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/1211:45 am -
Nonstop2h 22m
Mon 9/149:43 am -
1 stop24h 26m
Deal found 8/23![Frontier logo]()
$106
This Cheapflightsfares deal was found by Cheapflights users on 8/25. 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.
Mon 9/146:15 am -
Nonstop2h 20m
Thu 9/179:05 am -
Nonstop2h 25m
Deal found 8/25![Frontier logo]()
$101
This Cheapflightsfares deal was found by Cheapflights users on 8/24. 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 9/1611:45 am -
Nonstop2h 22m
Fri 10/210:29 pm -
Nonstop2h 18m
Deal found 8/24![Frontier logo]()
$104
This Cheapflightsfares deal was found by Cheapflights users on 8/25. 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.
Thu 9/176:45 pm -
1 stop16h 25m
Thu 9/249:05 am -
Nonstop2h 25m
Deal found 8/25![Frontier logo]()
$111
This Cheapflightsfares deal was found by Cheapflights users on 8/26. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/1811:45 am -
Nonstop2h 22m
Tue 9/2210:29 pm -
Nonstop2h 18m
Deal found 8/26![Frontier logo]()
$105
This Expedia deal was found by Cheapflights users on 8/26. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2211:45 am -
Nonstop2h 22m
Mon 10/56:38 pm -
1 stop15h 31m
Deal found 8/26![Frontier logo]()
$112
This Booking.com deal was found by Cheapflights users on 8/22. Clicking the “Pick Dates” 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 9/225:44 pm -
1 stop5h 00m
Sat 9/269:05 am -
Nonstop2h 25m
Deal found 8/22![Frontier logo]()
$113
This American Airlines deal was found by Cheapflights users on 8/24. 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.
Tue 9/221:04 pm -
1 stop4h 18m
Tue 9/298:20 am -
1 stop4h 46m
Deal found 8/24![American Airlines logo]()
$319
This Mytrip deal was found by Cheapflights users on 8/23. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/2311:45 am -
Nonstop2h 22m
Wed 9/301:05 pm -
1 stop4h 54m
Deal found 8/23![Frontier logo]()
$114
This Cheapflightsfares deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 9/2411:45 am -
Nonstop2h 22m
Mon 9/2810:29 pm -
Nonstop2h 18m
Deal found 8/21![Frontier logo]()
$108
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 August 26, 2026.
Search for one-way flight options from Ontario to Colorado. Find affordable one-way fares based on user searches. Data last updated August 26, 2026.
This Super.com deal was found by Cheapflights users on 8/25. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/111:45 am -
Nonstop2h 22m
Deal found 8/25![Frontier logo]()
$33
This Jetabroad deal was found by Cheapflights users on 8/25. 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 Jetabroad is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/276:25 am -
Nonstop2h 21m
Deal found 8/25![Frontier logo]()
$34
This Kiwi.com deal was found by Cheapflights users on 8/25. 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 10/2111:52 am -
Nonstop2h 26m
Deal found 8/25![Frontier logo]()
$42
This Kiwi.com deal was found by Cheapflights users on 8/25. 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.
Tue 9/2211:45 am -
Nonstop2h 22m
Deal found 8/25![Frontier logo]()
$43
This Cheapflightsfares deal was found by Cheapflights users on 8/25. 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 10/1611:52 am -
Nonstop2h 26m
Deal found 8/25![Frontier logo]()
$44
This Cheapflightsfares deal was found by Cheapflights users on 8/24. 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 9/266:15 am -
Nonstop2h 20m
Deal found 8/24![Frontier logo]()
$49
This Trip.com deal was found by Cheapflights users on 8/24. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/2611:52 am -
Nonstop2h 26m
Deal found 8/24![Frontier logo]()
$52
This Frontier deal was found by Cheapflights users on 8/24. 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.
Thu 12/36:20 am -
Nonstop2h 24m
Deal found 8/24![Frontier logo]()
$61
This Cheapflightsfares deal was found by Cheapflights users on 8/24. 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.
Mon 11/166:25 am -
Nonstop2h 21m
Deal found 8/24![Frontier logo]()
$64
This Super.com deal was found by Cheapflights users on 8/24. 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.
Mon 10/196:15 am -
Nonstop2h 26m
Deal found 8/24![Frontier logo]()
$71
This Super.com deal was found by Cheapflights users on 8/25. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/211:45 am -
Nonstop2h 22m
Deal found 8/25![Frontier logo]()
$72
This Delta deal was found by Cheapflights users on 8/21. Clicking the “Pick Dates” 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 10/79:45 am -
1 stop6h 42m
Deal found 8/21![Delta logo]()
$169
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 August 26, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $101 (Cheapflightsfares) |
One-way from | $33 (Super.com) |
Popular in | July |
Cheapest in | September |
Average price | $243 |
Good round-trip deal | $301 or less |
Good one-way deal | $179 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 7,457,451 searches. Data last updated August 26, 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 Ontario - DEN Denver Intl
ONTDEN
Ontario
Wed 9/16
9:52 am-5:02 pm
1 stop6h 10m
Denver Intl
Tue 9/29
10:45 am-4:35 pm
1 stop6h 50m
$197
OntarioDenver
ONT Ontario - DEN Denver Intl
ONTDEN
Ontario
Sat 10/10
1:35 pm-7:34 pm
1 stop4h 59m
Denver Intl
Mon 10/19
5:25 am-8:55 am
1 stop4h 30m
$226
Quickest round-trip
OntarioDenver
ONT Ontario - DEN Denver Intl
ONTDEN
Ontario
Mon 1/11
5:00 am-8:11 am
Nonstop2h 11m
Denver Intl
Sat 1/23
7:05 pm-8:20 pm
Nonstop2h 15m
$237
OntarioDenver
ONT Ontario - DEN Denver Intl
ONTDEN
Ontario
Wed 9/23
1:18 pm-4:39 pm
Nonstop2h 21m
Denver Intl
Wed 9/30
7:35 pm-8:58 pm
Nonstop2h 23m
$237
OntarioDenver
ONT Ontario - DEN Denver Intl
ONTDEN
Ontario
Thu 1/7
5:00 am-8:11 am
Nonstop2h 11m
Denver Intl
Mon 1/11
5:15 am-12:20 pm
1 stop8h 05m
$277
OntarioDenver
ONT Ontario - DEN Denver Intl
ONTDEN
Ontario
Mon 10/5
5:30 am-11:55 am
2 stops5h 25m
Denver Intl
Thu 10/8
5:55 am-11:25 am
1 stop6h 30m
$283
OntarioDenver
ONT Ontario - DEN Denver Intl
ONTDEN
Ontario
Wed 9/9
6:00 am-12:09 pm
1 stop5h 09m
Denver Intl
Mon 9/14
5:30 am-9:02 am
1 stop4h 32m
$283
OntarioDenver
ONT Ontario - DEN Denver Intl
ONTDEN
Ontario
Mon 11/23
1:15 pm-8:29 pm
1 stop6h 14m
Denver Intl
Thu 11/26
12:53 pm-6:30 pm
1 stop6h 37m
$288
OntarioGrand Junction
ONT Ontario - GJT Grand Junction Regnl
ONTGJT
Ontario
Sat 9/12
5:15 pm-9:57 pm
1 stop3h 42m
Grand Junction Regnl
Mon 9/14
7:41 am-12:14 pm
1 stop5h 33m
$319
OntarioMontrose
ONT Ontario - MTJ Montrose County
ONTMTJ
Ontario
Sat 11/14
5:00 am-12:36 pm
1 stop6h 36m
Montrose County
Tue 11/17
7:15 am-12:33 pm
1 stop6h 18m
$323
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-MTJ
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-GJT
ONT-MTJ
What is the cheapest month to book a flight from Ontario to Colorado?
Currently, February is the cheapest month in which you can book a flight from Ontario to Colorado (average of $175). Flying from Ontario to Colorado in June is currently the most expensive (average of $342). 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 August 26, 2026.
It’s typically best to fly out from Ontario to Colorado in the evening. Doing so could potentially save you 53% on the flight price compared to flying at noon, which is usually more expensive.
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 August 26, 2026.
The most flights from ONT to USCO are scheduled on a Monday (14 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (6 on average).
How much does it cost to fly round-trip from Ontario to Colorado?
Airfare is below average for this route at the moment.
Ontario to Colorado flights typically cost between $140 and $324 in September.The cheapest round-trip price found within the last 5 days was $101 on Frontier (Sep 14-Sep 17).
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 August 22, 2026.
Travelers seeking maximum savings on their Ontario to Colorado flight should consider departing on Saturday evenings when fares are most often at their lowest. Monday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
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 August 26, 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.
Overall
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Overall
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Overall
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Overall
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Overall
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Overall
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Boarding
8.1
Comfort
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.
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Alternative routes for Ontario to Colorado
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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 August 26, 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 7,457,451 searches. Data last updated August 26, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$61 | Average$186 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$98 | Average$277 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$157 | Average$380 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$157 | Average$329 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$211 | Average$375 | FlexibilityNo cancel fee | On-time71% |