$64+ Cheap flights from Ontario (ONT) to the United States
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 5/8. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LAX
Apr 10 — Apr 171
Round-trip
1 adult, Economy
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Find cheap flights from Ontario to USA with Cheapflights
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Cheapest flights from Ontario to USAExplore the most affordable flight options available from Ontario to USA. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 11, 2026.
Explore the most affordable flight options available from Ontario to USA. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 11, 2026.
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/2412:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 5/36:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/5![Frontier logo]()
$80
This Frontier 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 Frontier 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
Fri 4/176:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/6![Frontier logo]()
$81
This Cheapflightsfares deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 4/2612:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Mon 5/410:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/7![Frontier logo]()
$82
This Cheapflightsfares 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/86:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Tue 4/1410:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/6![Frontier logo]()
$83
This Super.com deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 4/2012:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Thu 4/236:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$87
This Cheapflightsfares deal was found by Cheapflights users on 3/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/85:33 pm
ONT
- DEN
Nonstop2h 25m
Frontier
Tue 5/1210:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/8![Frontier logo]()
$88
This Frontier deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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
Thu 4/166:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$89
This Super.com deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 5/1312:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Tue 5/1910:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/7![Frontier logo]()
$90
This Kiwi.com deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 4/66:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Wed 4/810:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$91
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/2912:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 5/36:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/6![Frontier logo]()
$93
This Cheapflightsfares deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 4/106:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Tue 4/1410:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$94
This Super.com deal was found by Cheapflights users on 3/9. Clicking the “Pick Dates” 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 4/28:49 am
ONT
- SFO
Nonstop1h 41m
Frontier
Mon 4/68:48 am
SFO
- ONT
Nonstop1h 37m
Frontier
Deal found 3/9![Frontier logo]()
$117
Best flights from Ontario to USADiscover carefully curated flight deals from Ontario to USA that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated March 11, 2026.
Discover carefully curated flight deals from Ontario to USA that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated March 11, 2026.
This Southwest deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 5/14:25 pm
ONT
- SEA
1 stop6h 05m
Southwest
Fri 5/85:00 am
SEA
- ONT
1 stop5h 25m
Southwest
Deal found 3/10![Southwest logo]()
$171
This Delta deal was found by Cheapflights users on 3/8. Clicking the “Pick Dates” 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 5/206:45 am
ONT
- SEA
Nonstop3h 04m
Delta
Wed 5/277:50 pm
SEA
- ONT
Nonstop2h 44m
Delta
Deal found 3/8![Delta logo]()
$188
This Alaska Airlines deal was found by Cheapflights users on 3/8. Clicking the “Pick Dates” 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 5/93:26 pm
ONT
- SEA
Nonstop2h 51m
Alaska Airlines
Sat 5/168:30 am
SEA
- ONT
Nonstop2h 40m
Alaska Airlines
Deal found 3/8![Alaska Airlines logo]()
$202
This United Airlines deal was found by Cheapflights users on 3/8. Clicking the “Pick Dates” 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 4/86:49 pm
ONT
- SFO
Nonstop1h 29m
United Airlines
Wed 4/1510:50 am
SFO
- ONT
Nonstop1h 30m
United Airlines
Deal found 3/8![United Airlines logo]()
$217
This JetBlue deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/1011:59 pm
ONT
- JFK
Nonstop5h 22m
JetBlue
Thu 8/207:35 pm
JFK
- ONT
Nonstop6h 05m
JetBlue
Deal found 3/10![JetBlue logo]()
$337
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.
Wed 4/156:55 am
ONT
- DEN
Nonstop2h 10m
Southwest
Sat 4/188:00 pm
DEN
- ONT
Nonstop2h 20m
Southwest
Deal found 3/6![Southwest logo]()
$189
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/306:00 am
ONT
- SFO
Nonstop1h 29m
United Airlines
Mon 5/48:10 am
SFO
- ONT
Nonstop1h 31m
United Airlines
Deal found 3/6![United Airlines logo]()
$217
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.
Sat 5/231:29 pm
ONT
- DEN
1 stop5h 23m
Delta
Tue 5/266:05 am
DEN
- ONT
1 stop7h 30m
Delta
Deal found 3/6![Delta logo]()
$221
This Southwest deal was found by Cheapflights users on 3/8. Clicking the “Pick Dates” 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 4/174:25 pm
ONT
- SEA
1 stop6h 05m
Southwest
Sun 4/195:00 am
SEA
- ONT
1 stop6h 30m
Southwest
Deal found 3/8![Southwest logo]()
$214
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.
Sat 5/231:29 pm
ONT
- DEN
1 stop5h 23m
Delta
Sat 5/307:55 am
DEN
- ONT
1 stop5h 24m
Delta
Deal found 3/5![Delta logo]()
$221
This Alaska Airlines deal was found by Cheapflights users on 3/9. Clicking the “Pick Dates” 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 4/27:08 pm
ONT
- SEA
Nonstop2h 49m
Alaska Airlines
Fri 4/1010:48 pm
SEA
- ONT
1 stop21h 35m
Alaska Airlines
Deal found 3/9![Alaska Airlines logo]()
$250
This Alaska Airlines deal was found by Cheapflights users on 3/9. Clicking the “Pick Dates” 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 8/35:38 pm
ONT
- HNL
1 stop9h 34m
Multiple Airlines
Thu 8/612:22 pm
HNL
- ONT
1 stop8h 32m
Multiple Airlines
Deal found 3/9![Multiple Airlines logo]()
$507
This United Airlines deal was found by Cheapflights users on 3/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/161:30 pm
ONT
- SFO
Nonstop1h 29m
United Airlines
Mon 5/189:23 pm
SFO
- ONT
Nonstop1h 36m
United Airlines
Deal found 3/9![United Airlines logo]()
$237
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.
Mon 4/65:09 pm
ONT
- DEN
1 stop4h 22m
Delta
Sat 4/116:15 pm
DEN
- ONT
1 stop5h 33m
Delta
Deal found 3/6![Delta logo]()
$221
This Southwest deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 4/710:30 am
ONT
- DEN
1 stop4h 55m
Southwest
Tue 4/146:45 am
DEN
- ONT
2 stops5h 50m
Southwest
Deal found 3/7![Southwest logo]()
$226
This Delta deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 3/255:53 pm
ONT
- SEA
Nonstop2h 57m
Delta
Tue 3/317:50 pm
SEA
- ONT
Nonstop2h 44m
Delta
Deal found 3/7![Delta logo]()
$227
This Alaska Airlines deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 5/157:41 pm
ONT
- SEA
Nonstop2h 49m
Alaska Airlines
Sun 5/1710:25 am
SEA
- ONT
1 stop6h 52m
Alaska Airlines
Deal found 3/10![Alaska Airlines logo]()
$280
This Southwest deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 3/305:25 pm
ONT
- SFO
2 stops6h 45m
Southwest
Tue 3/315:05 am
SFO
- ONT
1 stop4h 35m
Southwest
Deal found 3/7![Southwest logo]()
$243
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/46:00 am
ONT
- SFO
Nonstop1h 29m
United Airlines
Sun 4/58:25 am
SFO
- ONT
Nonstop1h 31m
United Airlines
Deal found 3/6![United Airlines logo]()
$268
This Alaska Airlines deal was found by Cheapflights users on 3/8. Clicking the “Pick Dates” 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 4/233:26 pm
ONT
- SFO
1 stop5h 57m
Alaska Airlines
Thu 4/307:00 am
SFO
- ONT
1 stop16h 59m
Alaska Airlines
Deal found 3/8![Alaska Airlines logo]()
$283
This Southwest deal was found by Cheapflights users on 3/8. Clicking the “Pick Dates” 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 4/152:25 pm
ONT
- SFO
2 stops7h 40m
Southwest
Mon 4/204:05 pm
SFO
- ONT
2 stops7h 00m
Southwest
Deal found 3/8![Southwest logo]()
$247
This United Airlines deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/25:00 am
ONT
- DEN
Nonstop2h 22m
United Airlines
Mon 5/47:10 pm
DEN
- ONT
Nonstop2h 26m
United Airlines
Deal found 3/10![United Airlines logo]()
$282
This JetBlue deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/1111:59 pm
ONT
- JFK
Nonstop5h 22m
JetBlue
Mon 8/177:35 pm
JFK
- ONT
Nonstop6h 05m
JetBlue
Deal found 3/10![JetBlue logo]()
$382
This Alaska Airlines deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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.
Tue 5/56:00 am
ONT
- DEN
1 stop9h 02m
Alaska Airlines
Wed 5/68:00 am
DEN
- ONT
2 stops16h 48m
Alaska Airlines
Deal found 3/10![Alaska Airlines logo]()
$301
This Southwest deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 4/171:50 pm
ONT
- HOU
Nonstop3h 00m
Southwest
Mon 4/208:05 am
HOU
- ONT
Nonstop3h 25m
Southwest
Deal found 3/10![Southwest logo]()
$257
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.
Wed 4/227:00 am
ONT
- DFW
2 stops12h 37m
Delta
Wed 4/294:27 pm
DFW
- ONT
1 stop8h 10m
Delta
Deal found 3/6![Delta logo]()
$294
This JetBlue deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/711:59 pm
ONT
- JFK
Nonstop5h 22m
JetBlue
Wed 8/127:35 pm
JFK
- ONT
Nonstop6h 05m
JetBlue
Deal found 3/10![JetBlue logo]()
$392
This United Airlines deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 4/236:05 am
ONT
- IAH
Nonstop3h 10m
United Airlines
Mon 4/275:00 am
IAH
- ONT
1 stop6h 56m
United Airlines
Deal found 3/7![United Airlines logo]()
$303
This Southwest deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 4/303:00 pm
ONT
- HOU
1 stop5h 35m
Southwest
Mon 5/47:50 pm
HOU
- ONT
1 stop5h 15m
Southwest
Deal found 3/7![Southwest logo]()
$257
This Alaska Airlines 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/17:08 pm
ONT
- SEA
Nonstop2h 49m
Alaska Airlines
Sat 4/48:26 am
SEA
- ONT
1 stop7h 16m
Alaska Airlines
Deal found 3/6![Alaska Airlines logo]()
$320
Last-minute flights from Ontario to USADiscover last-minute flight deals from Ontario to USA. Data last updated March 11, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to USA. Data last updated March 11, 2026 and is based on user searches.
This KAYAK 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/316:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Tue 4/710:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/6![Frontier logo]()
$88
This Super.com deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 3/316:15 am
ONT
- DEN
Nonstop2h 20m
Frontier
Mon 4/610:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$90
This Super.com deal was found by Cheapflights users on 3/9. Clicking the “Pick Dates” 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 4/28:49 am
ONT
- SFO
Nonstop1h 41m
Frontier
Mon 4/68:48 am
SFO
- ONT
Nonstop1h 37m
Frontier
Deal found 3/9![Frontier logo]()
$117
This Kiwi.com deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 4/66:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Wed 4/810:30 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$91
This Frontier deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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
Thu 4/166:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$89
This Cheapflightsfares 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/86:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Tue 4/1410:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/6![Frontier logo]()
$83
This Cheapflightsfares deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 4/106:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Tue 4/1410:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$94
This Frontier 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 Frontier 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
Fri 4/176:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/6![Frontier logo]()
$81
This Super.com deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 4/2012:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Thu 4/236:05 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/10![Frontier logo]()
$87
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/2412:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 5/36:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/5![Frontier logo]()
$80
This Cheapflightsfares deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 4/2612:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Mon 5/410:29 pm
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/7![Frontier logo]()
$82
This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/2912:59 am
ONT
- DEN
Nonstop2h 16m
Frontier
Sun 5/36:00 am
DEN
- ONT
Nonstop2h 26m
Frontier
Deal found 3/6![Frontier logo]()
$93
One-way flights from Ontario to USASearch for one-way flight options from Ontario to USA. Find affordable one-way fares based on user searches. Data last updated March 11, 2026.
Search for one-way flight options from Ontario to USA. Find affordable one-way fares based on user searches. Data last updated March 11, 2026.
This Frontier deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 5/88:26 am
ONT
- IAH
Nonstop3h 20m
Frontier
Deal found 3/7![Frontier logo]()
$64
This Flightnetwork deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/28:49 am
ONT
- SFO
Nonstop1h 41m
Frontier
Deal found 3/10![Frontier logo]()
$65
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/57:29 pm
ONT
- SFO
1 stop21h 23m
Frontier
Deal found 3/6![Frontier logo]()
$66
This Kiwi.com deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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 4/2211:44 am
ONT
- SFO
1 stop20h 39m
Frontier
Deal found 3/10![Frontier logo]()
$67
This Expedia deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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.
Mon 6/110:10 am
ONT
- SFO
Nonstop1h 33m
Frontier
Deal found 3/7![Frontier logo]()
$68
This Expedia deal was found by Cheapflights users on 3/9. Clicking the “Pick Dates” 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.
Sat 6/610:10 am
ONT
- SFO
Nonstop1h 33m
Frontier
Deal found 3/9![Frontier logo]()
$69
This Cheapflightsfares deal was found by Cheapflights users on 3/7. Clicking the “Pick Dates” 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 4/106:20 am
ONT
- DEN
Nonstop2h 23m
Frontier
Deal found 3/7![Frontier logo]()
$70
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/412:59 am
ONT
- IAH
1 stop12h 08m
Frontier
Deal found 3/6![Frontier logo]()
$71
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/84:52 pm
ONT
- DEN
1 stop6h 28m
Frontier
Deal found 3/6![Frontier logo]()
$71
This Trip.com 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/127:29 pm
ONT
- ORD
1 stop9h 18m
Frontier
Deal found 3/6![Frontier logo]()
$72
This Jetabroad deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” 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.
Sat 5/238:17 pm
ONT
- SFO
Nonstop1h 38m
Frontier
Deal found 3/10![Frontier logo]()
$72
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/188:59 pm
ONT
- DEN
1 stop6h 00m
Frontier
Deal found 3/6![Frontier logo]()
$72
Find flight deals from Ontario to USA
Keep the following information in mind while searching for Ontario to USA flight deals. Data was last updated March 11, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $80 (Cheapflightsfares) |
One-way from | $64 (Frontier) |
Popular in | December |
Cheapest in | January |
Average price | $337 |
Good round-trip deal | $132 or less |
Good one-way deal | $72 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Ontario to USA 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 11, 2026.
Use the filters below to find and compare flights from Ontario to the United States that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
OntarioSeattle
ONT - SEA
ONTSEA
Ontario
Fri 5/1
4:25 pm-10:30 pm
1 stop6h 05m
Seattle/Tacoma Intl
Fri 5/8
5:00 am-10:25 am
1 stop5h 25m
$171
OntarioSeattle
ONT - SEA
ONTSEA
Ontario
Wed 5/20
6:45 am-9:49 am
Nonstop3h 04m
Seattle/Tacoma Intl
Wed 5/27
7:50 pm-10:34 pm
Nonstop2h 44m
$188
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Wed 4/15
6:55 am-10:05 am
Nonstop2h 10m
Denver Intl
Sat 4/18
8:00 pm-9:20 pm
Nonstop2h 20m
$189
OntarioSeattle
ONT - SEA
ONTSEA
Ontario
Sat 5/9
3:26 pm-6:17 pm
Nonstop2h 51m
Seattle/Tacoma Intl
Sat 5/16
8:30 am-11:10 am
Nonstop2h 40m
$202
OntarioSeattle
ONT - SEA
ONTSEA
Ontario
Fri 4/17
4:25 pm-10:30 pm
1 stop6h 05m
Seattle/Tacoma Intl
Sun 4/19
5:00 am-11:30 am
1 stop6h 30m
$214
Quickest round-trip
OntarioSan Francisco
ONT - SFO
ONTSFO
Ontario
Wed 4/8
6:49 pm-8:18 pm
Nonstop1h 29m
San Francisco
Wed 4/15
10:50 am-12:20 pm
Nonstop1h 30m
$217
OntarioSan Francisco
ONT - SFO
ONTSFO
Ontario
Thu 4/30
6:00 am-7:29 am
Nonstop1h 29m
San Francisco
Mon 5/4
8:10 am-9:41 am
Nonstop1h 31m
$217
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 5/23
1:29 pm-7:52 pm
1 stop5h 23m
Denver Intl
Tue 5/26
6:05 am-12:35 pm
1 stop7h 30m
$221
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Sat 5/23
1:29 pm-7:52 pm
1 stop5h 23m
Denver Intl
Sat 5/30
7:55 am-12:19 pm
1 stop5h 24m
$221
OntarioDenver
ONT - DEN
ONTDEN
Ontario
Mon 4/6
5:09 pm-10:31 pm
1 stop4h 22m
Denver Intl
Sat 4/11
6:15 pm-10:48 pm
1 stop5h 33m
$221
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Ontario to USA
Have a flexible travel schedule? Discover the best time to fly to USA from Ontario with our price prediction graph.
ONT-SEA
ONT-SFO
ONT-JFK
ONT-DEN
ONT-HNL
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 the United States
ONT-US0
ONT-SEA
ONT-SFO
ONT-JFK
ONT-DEN
What is the cheapest month to book a flight from Ontario to USA?
Currently, May is the cheapest month in which you can book a flight from Ontario to USA (average of $32). Flying from Ontario to USA in January is currently the most expensive (average of $53). 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 US?
Find hourly flight availability from Ontario to USA. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 11, 2026.
A simple way to save on the total cost of your ticket is to fly from Ontario to USA in the evening. If you’re flexible enough to do this you can expect to save up to 39% on your trip compared to booking a flight in the afternoon.
What is the cheapest day to fly from Ontario to USA?
Use this chart to determine the cheapest time to fly round-trip from Ontario to USA. Price data was last updated on February 21, 2026.
Travelers seeking maximum savings on their Ontario to USA flight should consider departing on Saturday evenings when fares are most often at their lowest. Wednesday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.
How often are flights from Ontario to the United States delayed?
About 13% of weekly flights between Ontario and United States have experienced delays in the past year, with the average delay time being 123 minutes.
What is the most punctual flight time for Ontario to the United States flights?
Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the evening tend to experience delays more often.
What day of the week experiences the fewest flight delays on this route?
Saturday tends to have the lowest number of delays on this route, whereas Wednesday has historically faced a higher average of delays compared to other days of the week.
Which airline has the best punctuality record on Ontario to the United States flights?
Over the last year, Delta have had the lowest number of delays on this route, with just 4% of flights being delayed.
Reviews of airlines servicing USA
Get insights into the airlines that provide service to USA. 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 USA. Reviews last updated March 11, 2026.
Read reviews from past customers who have flown Southwest,Delta, andUnited Airlines from Ontario to the United States. 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
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Reviews
1 / 20
10.0
ExcellentWilliam Drew,Nov 2025
SJC - HNL
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Reviews
1 / 20
10.0
ExcellentWilliam Drew,Nov 2025
SJC - HNL
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Reviews
1 / 20
10.0
ExcellentWilliam Drew,Nov 2025
SJC - HNL
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Reviews
1 / 20
10.0
ExcellentWilliam Drew,Nov 2025
SJC - HNL
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Reviews
1 / 20
10.0
ExcellentWilliam Drew,Nov 2025
SJC - HNL
Crew
8.6
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Food
7.0
Reviews
1 / 20
10.0
ExcellentWilliam Drew,Nov 2025
SJC - HNL
Related info for your journey
Find useful and relevant information for your journey from Ontario to USA. 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 USA
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Complete your trip
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Ontario and USA flights
Browse other Ontario and USA flight options. Last updated on March 11, 2026.
Popular flight searches
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Ontario to USA flights
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Consider these flights traveling to USA regions.
Top 8 airlines flying from Ontario to USA
Discover the top 8 airlines that operate flights from Ontario to USA. 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 11, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$24 | Average$152 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$36 | Average$201 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$59 | Average$356 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$78 | Average$287 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$97 | Average$367 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$155 | Average$335 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$158 | Average$397 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$249 | Average$417 | FlexibilityNo cancel fee | On-time71% |