Cheap Flights from Ontario, CA to Chicago, IL from $103

On Cheapflightsplus.com you will find 3 direct and 189 connecting flights from Ontario to Chicago. You can compare airfare deals from 4 airlines and multiple travel sites from $103, book and save on cheap plane tickets and last minute offers. Also check out ONT-CHI flight schedule to find best flight time, convenient departure and arrival airports.

Flight Information

Below we will explain in detail what the flights cost on the destination from Ontario to Chicago depends on and how to choose the most interesting flight option for you.

Distance between Ontario and Chicago is 2751 miles. Time difference between the cities is 2h. Airplanes depart 00:59 to 20:09 from 2 Ontario airports and arrive 00:59 to 20:09 to 7 Chicago airports. Average flight time is 4h 3m.

  • The fastest flight 4h 2m
  • Average flight time 4h 3m
  • The earliest flight 00:59
  • The latest flight 20:09
  • Distance 1710 ml

The cheapest months to travel to Chicago are july (from 103 $), october (from 118 $), september (from 119 $).

The most expensive months are february (from 329 $), december (from 266 $), august (from 133 $).

What is the lowest airfare Ontario to Chicago?

The cheapest plane ticket found by our users is $103. This airfare is for economy class on one-way F93132 flight by Frontier Airlines for July 4, 2025 which leaves Ontario Int. in Ontario at 12:48 am and arrives at Chicago Midway at 22:18.

Economy class
$103
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Business class
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First class
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Flight Schedule Ontario (California) to Chicago (Illinois)

00:59 — 11:40
8h 41m flight time
Find flight
from$103
00:59 — 04:19 Ontario — Denver
F91500 Frontier Airlines
3h 57m stop
08:15 — 11:41 Denver — Chicago
F92210 Frontier Airlines
00:59 — 23:59
21h flight time
Find flight
from$108
00:59 — 04:19 Ontario — Denver
F91500 Frontier Airlines
16h 3m stop
20:31 — 00:10 Denver — Chicago
F93174 Frontier Airlines
00:59 — 23:53
20h 54m flight time
Find flight
from$119
00:59 — 04:19 Ontario — Denver
F91500 Frontier Airlines
16h 2m stop
20:31 — 00:10 Denver — Chicago
F93172 Frontier Airlines
06:00 — 20:56
12h 56m flight time
Find flight
from$108
06:00 — 07:13 Ontario — Las Vegas
F92232 Frontier Airlines
7h 50m stop
15:00 — 21:06 Las Vegas — Chicago
F92146 Frontier Airlines
06:00 — 14:56
6h 56m flight time
Find flight
from$126
06:00 — 07:10 Ontario — Las Vegas
F92232 Frontier Airlines
2h 9m stop
09:19 — 14:56 Las Vegas — Chicago
F92330 Frontier Airlines
07:00 — 13:02
4h 2m flight time
Find flight
from$158
Ontario — Chicago
UA356 United Airlines
07:00 — 13:03
4h 3m flight time
Find flight
from$163
Ontario — Chicago
UA2226 United Airlines
07:00 — 13:03
4h 3m flight time
Find flight
from$417
Ontario — Chicago
UA2649 United Airlines
11:39 — 22:04
8h 25m flight time
Find flight
from$119
12:00 — 14:38 Ontario — Seattle
HA6289 Hawaiian Airlines
1h 40m stop
16:25 — 22:30 Seattle — Chicago
HA6821 Hawaiian Airlines
11:39 — 22:04
8h 25m flight time
Find flight
from$127
12:00 — 14:38 Ontario — Seattle
AS1111 Alaska Airlines
1h 40m stop
16:25 — 22:30 Seattle — Chicago
AS941 Alaska Airlines
12:48 — 22:18
7h 30m flight time
Find flight
from$103
12:48 — 18:19 Ontario — Houston
F93132 Frontier Airlines
1h 27m stop
19:45 — 22:23 Houston — Chicago
F93282 Frontier Airlines
13:31 — 23:59
8h 28m flight time
Find flight
from$118
12:00 — 14:38 Ontario — Seattle
HA6289 Hawaiian Airlines
1h 36m stop
17:54 — 23:59 Seattle — Chicago
HA6819 Hawaiian Airlines
13:31 — 23:59
8h 28m flight time
Find flight
from$127
12:00 — 14:38 Ontario — Seattle
AS1111 Alaska Airlines
1h 36m stop
17:54 — 23:59 Seattle — Chicago
AS538 Alaska Airlines
17:14 — 21:06+1day
25h 52m flight time
Find flight
from$133
17:14 — 18:28 Ontario — Las Vegas
F91358 Frontier Airlines
20h 32m stop
15:00 — 21:06 Las Vegas — Chicago
F92146 Frontier Airlines
17:21 — 00:10+2days
28h 49m flight time
Find flight
from$108
17:21 — 20:44 Ontario — Denver
F92908 Frontier Airlines
23h 47m stop
20:31 — 00:10 Denver — Chicago
F93172 Frontier Airlines
Full flight schedule will help you in detecting at what time planes fly from Ontario to Chicago. You can also specify the concrete flights and airlines on the route and how long the flight actually is. Use the calendar for today, tomorrow or other specific date as some flights are available only on certain days of the week.
*Departure and arrival times - local. Updated on October 16, 2025.

Popular Airlines on the Route

The flight Ontario — Chicago is served by 4 regular airlines and 1 low-cost airline. Most of the flights on this route are operated by Alaska Airlines - 45 departures per week at the price of from $ 127 . And the most expensive tickets are offered by Alaska Airlines airline - from $ 7004.

Direct flights

There are 3 nonstop flights on the route. The fastest direct flight is UA356 by United Airlines takes 4h 2m and the cheapest is F93132 by Frontier Airlines for $158.

  • UA - United Airlines
    from $158
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Connecting Flights

There are 189 flights with layovers on the route. The fastest connecting flight is UA2446 by United Airlines takes 6h 2m and the cheapest is F93132 by Frontier Airlines for $103.

  • AS - Alaska Airlines
    from $127
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  • F9 - Frontier Airlines
    from $103
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  • HA - Hawaiian Airlines
    from $118
    Find
  • UA - United Airlines
    from $167
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See more connecting flights

Airports

You can fly from Ontario to Chicago from 2 airports (Ontario Int., International Heliport).

Ontario airports

  • Ontario Int.-ONT
    from $103
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  • International Heliport-JIO
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Chicago airports

  • O'Hare International-ORD
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  • Midway-MDW
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  • Dupage County-DPA
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  • Chicago FSS-CHI
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  • Merrill C Meigs (closed)-CGX
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  • Pal-Waukee-PWK
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  • Chicago NAS-NOH
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How to book a plane ticket yourself?

How to book an air ticket yourself?
  • Fill in the search parameters — cities of departure and destination, departure and return dates and click «Find flights»
  • Select the best flight that you like. Please, check the airports of departure and arrival. Select the best fare, but pay attention to the following flight details - airports of departure and arrival, flight duration and layovers. Please use filters and sort to find the best flight.
  • Click «Buy» when you are ready — our system will redirect you to the site that sells the selected flight ticket.
  • Fill in all passenger and payment information — passport and contact information, please double check all passengers’ names and make a payment for your itinerary.
  • That's it — you will receive an email with your e-ticket usually within 10 minutes after your flight is confirmed. Please, print the e-ticket and have it with you at the airport. You would need to have only a passport and/or a required form of ID to travel. Please, check your Visa requirements if you travel outside of the United States or Canada.

    To find a plane ticket, please select dates.

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