$28+ Cheap flights from Colorado to Ontario (ONT)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/20. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ONT
Oct 24 — Oct 311
Round-trip
1 adult, Economy
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Find cheap flights from Colorado to Ontario with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
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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 Colorado to Ontario
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Cheapest flights from Colorado to OntarioExplore the most affordable flight options available from Colorado to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 24, 2026.
Explore the most affordable flight options available from Colorado to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 24, 2026.
This Booking.com deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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.
Wed 10/2110:29 pm -
Nonstop2h 21m
Sat 10/246:15 am -
Nonstop2h 26m
Deal found 9/20![Frontier logo]()
$66
This Cheapflightsfares deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” 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 10/179:01 am -
Nonstop2h 28m
Sat 10/2411:52 am -
Nonstop2h 26m
Deal found 9/18![Frontier logo]()
$67
This Cheapflightsfares deal was found by Cheapflights users on 9/22. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/119:10 am -
Nonstop2h 25m
Wed 11/1811:52 am -
Nonstop2h 21m
Deal found 9/22![Frontier logo]()
$68
This Trip.com deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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.
Wed 12/98:55 pm -
Nonstop2h 22m
Thu 12/106:00 am -
Nonstop2h 24m
Deal found 9/20![Frontier logo]()
$75
This Super.com deal was found by Cheapflights users on 9/22. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/2110:29 pm -
Nonstop2h 21m
Mon 10/2611:52 am -
Nonstop2h 26m
Deal found 9/22![Frontier logo]()
$76
This Cheapflightsfares deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/1910:29 pm -
Nonstop2h 21m
Thu 10/2211:52 am -
Nonstop2h 26m
Deal found 9/19![Frontier logo]()
$77
This Booking.com deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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.
Sat 10/2410:29 pm -
Nonstop2h 21m
Mon 10/2611:52 am -
Nonstop2h 26m
Deal found 9/20![Frontier logo]()
$78
This Trip.com deal was found by Cheapflights users on 9/23. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/98:55 pm -
Nonstop2h 22m
Wed 12/166:00 am -
Nonstop2h 24m
Deal found 9/23![Frontier logo]()
$79
This Frontier deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 11/2110:52 pm -
Nonstop2h 22m
Mon 11/235:01 am -
Nonstop2h 20m
Deal found 9/20![Frontier logo]()
$88
This Kiwi.com deal was found by Cheapflights users on 9/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/199:10 am -
Nonstop2h 25m
Mon 11/235:01 am -
Nonstop2h 20m
Deal found 9/21![Frontier logo]()
$92
This Super.com deal was found by Cheapflights users on 9/21. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/149:01 am -
Nonstop2h 28m
Sat 10/176:15 am -
Nonstop2h 26m
Deal found 9/21![Frontier logo]()
$96
This Southwest deal was found by Cheapflights users on 9/22. 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.
Tue 12/158:55 am -
1 stop6h 45m
Wed 12/161:55 pm -
1 stop4h 55m
Deal found 9/22![Southwest logo]()
$294
Best flights from Colorado to OntarioDiscover carefully curated flight deals from Colorado to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 24, 2026.
Discover carefully curated flight deals from Colorado to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 24, 2026.
This Alaska Airlines deal was found by Cheapflights users on 9/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/103:22 pm -
1 stop8h 37m
Tue 1/57:10 am -
1 stop5h 57m
Deal found 9/21![Alaska Airlines logo]()
$177
This Southwest deal was found by Cheapflights users on 9/23. 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 10/247:55 am -
2 stops6h 50m
Tue 10/276:20 am -
1 stop6h 00m
Deal found 9/23![Southwest logo]()
$182
This Delta deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” 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 11/712:57 pm -
1 stop4h 26m
Mon 11/95:04 pm -
1 stop5h 05m
Deal found 9/18![Delta logo]()
$198
This Frontier deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” 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 11/1310:37 pm -
2 stops18h 44m
Sun 11/156:25 am -
Nonstop2h 21m
Deal found 9/18![Frontier logo]()
$222
This United Airlines deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/247:35 pm -
Nonstop2h 23m
Tue 10/271:29 pm -
Nonstop2h 16m
Deal found 9/19![United Airlines logo]()
$257
This American Airlines deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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.
Sun 11/111:58 am -
1 stop4h 37m
Tue 11/101:23 pm -
1 stop4h 38m
Deal found 9/20![American Airlines logo]()
$339
This Southwest deal was found by Cheapflights users on 9/21. 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.
Wed 11/116:50 am -
1 stop6h 20m
Fri 11/135:35 am -
2 stops6h 15m
Deal found 9/21![Southwest logo]()
$230
This Alaska Airlines deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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.
Sat 10/247:07 am -
1 stop7h 09m
Tue 10/2711:29 am -
1 stop5h 56m
Deal found 9/19![Alaska Airlines logo]()
$257
This United Airlines deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” 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 11/77:25 pm -
Nonstop2h 26m
Mon 11/95:00 am -
Nonstop2h 17m
Deal found 9/18![United Airlines logo]()
$258
This Southwest deal was found by Cheapflights users on 9/22. 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.
Tue 12/158:55 am -
1 stop6h 45m
Wed 12/161:55 pm -
1 stop4h 55m
Deal found 9/22![Southwest logo]()
$294
This Delta deal was found by Cheapflights users on 9/23. 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 11/78:17 am -
1 stop5h 19m
Tue 11/105:04 pm -
1 stop4h 18m
Deal found 9/23![Delta logo]()
$355
This American Airlines deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/167:18 pm -
1 stop4h 35m
Sun 10/186:15 am -
1 stop3h 59m
Deal found 9/20![American Airlines logo]()
$373
This United Airlines deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/241:34 pm -
2 stops10h 17m
Sun 11/15:00 am -
1 stop6h 45m
Deal found 9/20![United Airlines logo]()
$344
This Alaska Airlines deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” 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 10/306:55 pm -
1 stop5h 59m
Sun 11/16:00 am -
1 stop6h 58m
Deal found 9/18![Alaska Airlines logo]()
$352
This Delta deal was found by Cheapflights users on 9/23. 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 11/76:07 pm -
1 stop5h 04m
Mon 11/95:04 pm -
1 stop4h 18m
Deal found 9/23![Delta logo]()
$355
This United Airlines deal was found by Cheapflights users on 9/21. 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.
Tue 11/37:25 pm -
Nonstop2h 26m
Mon 11/95:00 am -
Nonstop2h 17m
Deal found 9/21![United Airlines logo]()
$353
This Delta deal was found by Cheapflights users on 9/23. 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.
Tue 11/36:07 pm -
1 stop5h 04m
Tue 11/105:04 pm -
1 stop4h 18m
Deal found 9/23![Delta logo]()
$355
This Southwest deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/152:55 pm -
2 stops6h 25m
Tue 10/206:10 am -
2 stops6h 05m
Deal found 9/19![Southwest logo]()
$379
This American Airlines deal was found by Cheapflights users on 9/22. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/3111:44 am -
1 stop4h 32m
Sat 11/76:30 am -
1 stop3h 59m
Deal found 9/22![American Airlines logo]()
$428
This Delta deal was found by Cheapflights users on 9/23. 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.
Wed 11/46:07 pm -
1 stop5h 04m
Mon 11/95:04 pm -
1 stop4h 18m
Deal found 9/23![Delta logo]()
$355
This United Airlines deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 11/267:05 am -
1 stop6h 28m
Wed 12/21:40 pm -
1 stop6h 15m
Deal found 9/19![United Airlines logo]()
$359
This Southwest deal was found by Cheapflights users on 9/22. 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.
Sat 10/246:05 am -
1 stop6h 05m
Sun 10/257:15 pm -
1 stop4h 20m
Deal found 9/22![Southwest logo]()
$388
This Delta deal was found by Cheapflights users on 9/22. 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.
Sat 10/248:17 am -
1 stop5h 19m
Mon 11/25:03 pm -
1 stop4h 19m
Deal found 9/22![Delta logo]()
$356
This American Airlines deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/156:33 pm -
1 stop5h 20m
Fri 10/231:05 pm -
2 stops8h 06m
Deal found 9/19![American Airlines logo]()
$439
This United Airlines deal was found by Cheapflights users on 9/22. 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.
Tue 11/177:05 am -
2 stops9h 28m
Wed 11/189:25 am -
2 stops10h 05m
Deal found 9/22![United Airlines logo]()
$370
This United Airlines deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/67:00 am -
1 stop6h 46m
Sat 10/101:52 pm -
2 stops7h 14m
Deal found 9/20![United Airlines logo]()
$374
This United Airlines deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 11/15:30 am -
2 stops7h 59m
Tue 11/109:25 am -
2 stops10h 12m
Deal found 9/20![United Airlines logo]()
$380
This United Airlines deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/301:40 pm -
2 stops10h 08m
Sat 10/311:29 pm -
1 stop6h 01m
Deal found 9/20![United Airlines logo]()
$383
This United Airlines deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/107:15 am -
1 stop6h 31m
Sat 10/175:00 am -
1 stop6h 35m
Deal found 9/19![United Airlines logo]()
$426
This United Airlines deal was found by Cheapflights users on 9/21. 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.
Tue 10/67:15 am -
1 stop6h 31m
Sat 10/1011:10 am -
2 stops8h 27m
Deal found 9/21![United Airlines logo]()
$430
Last-minute flights from Colorado to OntarioDiscover last-minute flight deals from Colorado to Ontario. Data last updated September 24, 2026 and is based on user searches.
Discover last-minute flight deals from Colorado to Ontario. Data last updated September 24, 2026 and is based on user searches.
This Super.com deal was found by Cheapflights users on 9/21. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/149:01 am -
Nonstop2h 28m
Sat 10/176:15 am -
Nonstop2h 26m
Deal found 9/21![Frontier logo]()
$96
This Cheapflightsfares deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/1510:29 pm -
Nonstop2h 21m
Mon 10/266:15 am -
Nonstop2h 26m
Deal found 9/20![Frontier logo]()
$88
This Super.com deal was found by Cheapflights users on 9/22. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/179:01 am -
Nonstop2h 28m
Mon 10/1911:52 am -
Nonstop2h 26m
Deal found 9/22![Frontier logo]()
$97
This Cheapflightsfares deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/1910:29 pm -
Nonstop2h 21m
Thu 10/2211:52 am -
Nonstop2h 26m
Deal found 9/19![Frontier logo]()
$77
This Booking.com deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/2010:29 pm -
Nonstop2h 21m
Tue 10/276:25 am -
Nonstop2h 21m
Deal found 9/20![Frontier logo]()
$67
This Booking.com deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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.
Wed 10/2110:29 pm -
Nonstop2h 21m
Thu 10/2211:52 am -
Nonstop2h 26m
Deal found 9/20![Frontier logo]()
$66
This Super.com deal was found by Cheapflights users on 9/22. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/2110:29 pm -
Nonstop2h 21m
Mon 10/2611:52 am -
Nonstop2h 26m
Deal found 9/22![Frontier logo]()
$76
This Kiwi.com deal was found by Cheapflights users on 9/22. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/2110:29 pm -
Nonstop2h 21m
Sat 10/246:15 am -
Nonstop2h 26m
Deal found 9/22![Frontier logo]()
$89
This Justfly.com deal was found by Cheapflights users on 9/22. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/2210:29 pm -
Nonstop2h 21m
Mon 10/2611:52 am -
Nonstop2h 26m
Deal found 9/22![Frontier logo]()
$98
This Booking.com deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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.
Sat 10/2410:29 pm -
Nonstop2h 21m
Mon 10/2611:52 am -
Nonstop2h 26m
Deal found 9/20![Frontier logo]()
$78
This United Airlines deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/241:34 pm -
2 stops10h 17m
Sun 11/15:00 am -
1 stop6h 45m
Deal found 9/20![United Airlines logo]()
$344
This American Airlines deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/266:00 am -
1 stop4h 10m
Mon 11/236:30 am -
1 stop3h 55m
Deal found 9/20![American Airlines logo]()
$339
One-way flights from Colorado to OntarioSearch for one-way flight options from Colorado to Ontario. Find affordable one-way fares based on user searches. Data last updated September 24, 2026.
Search for one-way flight options from Colorado to Ontario. Find affordable one-way fares based on user searches. Data last updated September 24, 2026.
This eDestinos deal was found by Cheapflights users on 9/21. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2010:29 pm -
Nonstop2h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$28
This Super.com deal was found by Cheapflights users on 9/22. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/179:01 am -
Nonstop2h 28m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$33
This Cheapflightsfares deal was found by Cheapflights users on 9/22. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/1210:29 pm -
Nonstop2h 22m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/22![Frontier logo]()
$34
This Kiwi.com deal was found by Cheapflights users on 9/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/1710:29 pm -
Nonstop2h 22m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$42
This Super.com deal was found by Cheapflights users on 9/21. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/1310:29 pm -
Nonstop2h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$43
This eDestinos deal was found by Cheapflights users on 9/21. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/1210:29 pm -
Nonstop2h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$44
This Mytrip deal was found by Cheapflights users on 9/23. 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.
Thu 10/2210:29 pm -
Nonstop2h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/23![Frontier logo]()
$61
This Cheapflightsfares deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 11/2310:52 pm -
Nonstop2h 22m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/19![Frontier logo]()
$64
This Super.com deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/1510:29 pm -
Nonstop2h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![Frontier logo]()
$71
This Cheapflightsfares deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 11/149:17 am -
Nonstop2h 25m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![Frontier logo]()
$72
This Kiwi.com deal was found by Cheapflights users on 9/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/224:26 pm -
2 stops41h 24m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/23![Multiple Airlines logo]()
$140
This Kiwi.com deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/262:06 pm -
3 stops44h 34m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/19![Multiple Airlines logo]()
$164
Find flight deals from Colorado to Ontario
Keep the following information in mind while searching for Colorado to Ontario flight deals. Data was last updated September 24, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $66 (Booking.com) |
One-way from | $28 (eDestinos) |
Popular in | June |
Cheapest in | February |
Average price | $202 |
Good round-trip deal | $153 or less |
Good one-way deal | $134 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Colorado to Ontario 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 September 24, 2026.
Use the filters below to find and compare flights from Colorado to Ontario that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Thu 10/29
7:25 pm-8:51 pm
Nonstop2h 26m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$79
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Sat 10/24
7:55 am-1:45 pm
2 stops6h 50m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$94
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Tue 10/20
5:25 am-8:55 am
1 stop4h 30m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$99
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Wed 11/11
8:10 am-12:17 pm
1 stop5h 07m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$99
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Tue 10/13
8:20 pm-9:45 pm
Nonstop2h 25m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$127
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Sat 10/24
7:35 pm-8:58 pm
Nonstop2h 23m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$129
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Wed 10/7
5:55 am-10:45 am
1 stop5h 50m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$154
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Mon 11/9
7:25 pm-8:51 pm
Nonstop2h 26m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$159
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Mon 11/23
6:00 am-12:29 pm
1 stop7h 29m
Ontario
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$169
DenverOntario
DEN Denver Intl - ONT Ontario
DENONT
Denver Intl
Thu 12/10
3:22 pm-10:59 pm
1 stop8h 37m
Ontario
Tue 1/5
7:10 am-2:07 pm
1 stop5h 57m
$177
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Colorado to Ontario
Have a flexible travel schedule? Discover the best time to fly to Ontario from Colorado with our price prediction graph.
DEN-ONT
GJT-ONT
MTJ-ONT
COS-ONT
DRO-ONT
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 Colorado to Ontario
USCO-ONT
DEN-ONT
GJT-ONT
MTJ-ONT
COS-ONT
What is the cheapest month to book a flight from Colorado to Ontario?
Currently, May is the cheapest month in which you can book a flight from Colorado to Ontario (average of $189). Flying from Colorado to Ontario in June is currently the most expensive (average of $304). 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 CO to ONT?
Find hourly flight availability from Colorado to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 24, 2026.
It’s optimal to fly from Colorado to Ontario in the evening. By choosing this option you can save up to 27% on the cost of your flight, compared to a flight at noon.
Weekly flight availability from Colorado to Ontario
Explore weekly flight availability from Colorado to Ontario. 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 September 24, 2026.
The most flights from USCO to ONT are scheduled on a Monday (12 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (3 on average).
How much does it cost to fly round-trip from Colorado to Ontario?
Airfare is below average for this route at the moment.
Colorado to Ontario flights typically cost between $129 and $281 in October.The cheapest round-trip price found within the last 5 days was $66 on Frontier (Oct 24-Oct 28).
How far ahead should I book a flight from Colorado to Ontario?
To ensure you get the cheapest price possible for a flight from Colorado to Ontario, you should look to book at least 48 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.
What is the cheapest day to fly from Colorado to Ontario?
Use this chart to determine the cheapest time to fly round-trip from Colorado to Ontario. Price data was last updated on September 19, 2026.
Travelers seeking maximum savings on their Colorado to Ontario flight should consider departing on Wednesday afternoons when fares are most often at their lowest. Monday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.
Related info for your journey
Find useful and relevant information for your journey from Colorado to Ontario. 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
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Ontario flight routes
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Alternative routes for Colorado to Ontario
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Ontario by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Colorado to Ontario by cabin class
Find flights from Colorado to Ontario, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Other flights to Ontario
Explore flights to Ontario departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 24, 2026.
Colorado and Ontario flights
Browse other Colorado and Ontario flight options. Last updated on September 24, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Colorado to Ontario flights
Consider these flights traveling from Colorado to Ontario.
Top 5 airlines flying from Colorado to Ontario
Discover the top 5 airlines that operate flights from Colorado to Ontario. 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 September 24, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$64 | Average$199 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$131 | Average$397 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$167 | Average$342 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$196 | Average$256 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$200 | Average$366 | FlexibilityNo cancel fee | On-time71% |