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Cheap flights from Ontario to Chicago from $75

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to Chicago departing on 4/14. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Ontario to Chicago

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
10:50 am - 8:37 pm
ONT
-
ORD
7h 47m
1 stop
Frontier Logo
9:42 pm - 11:49 pm
ORD
-
ONT
28h 07m
1 stop
$261Frontier
Thu, May 21 - Wed, May 27
Frontier Logo
8:06 pm - 11:01 pm
ONT
-
ORD
24h 55m
1 stop
Frontier Logo
4:05 pm - 7:35 am
ORD
-
ONT
17h 30m
1 stop
$266Frontier
Mon, May 18 - Wed, May 20
Frontier Logo
10:50 am - 8:37 pm
ONT
-
ORD
7h 47m
1 stop
Frontier Logo
9:42 pm - 3:09 pm
ORD
-
ONT
19h 27m
2 stops
$267Frontier
Thu, May 28 - Thu, Jun 4
Frontier Logo
12:59 am - 9:50 am
ONT
-
ORD
6h 51m
1 stop
Frontier Logo
8:55 am - 11:55 pm
ORD
-
ONT
17h 00m
2 stops
$269Frontier
Wed, Apr 15 - Sat, Apr 18
Frontier Logo
7:49 pm - 6:08 am
ONT
-
ORD
8h 19m
1 stop
Frontier Logo
6:14 pm - 11:58 pm
ORD
-
ONT
7h 44m
1 stop
$270Frontier
Thu, Apr 16 - Fri, Apr 17
Frontier Logo
7:44 pm - 6:08 am
ONT
-
ORD
8h 24m
1 stop
Frontier Logo
6:09 pm - 11:56 pm
ORD
-
ONT
7h 47m
1 stop
$271Frontier
Wed, Apr 15 - Sun, Apr 19
Frontier Logo
9:20 pm - 6:08 am
ONT
-
ORD
6h 48m
1 stop
Frontier Logo
9:30 am - 7:11 pm
ORD
-
ONT
11h 41m
1 stop
$272Frontier
Thu, Apr 30 - Thu, May 7
Frontier Logo
8:06 pm - 3:43 pm
ONT
-
ORD
17h 37m
1 stop
Frontier Logo
9:42 pm - 10:05 am
ORD
-
ONT
14h 23m
1 stop
$273Frontier
Thu, May 14 - Mon, May 18
Frontier Logo
9:26 pm - 12:24 pm
ONT
-
ORD
36h 58m
2 stops
Frontier Logo
3:23 pm - 10:37 pm
ORD
-
ONT
9h 14m
1 stop
$274Frontier
Tue, Apr 7 - Sat, Apr 18
Frontier Logo
9:02 pm - 6:20 am
ONT
-
ORD
7h 18m
1 stop
Frontier Logo
4:28 pm - 4:38 pm
ORD
-
ONT
26h 10m
2 stops
$275Frontier
Mon, Apr 13 - Thu, Apr 16

Frontier flights from Ontario to Chicago O'Hare Intl Airport

Our best Frontier deals on Ontario to Chicago O'Hare Intl Airport flight tickets
Frontier
May 21
ONT10:50 amOntario
7h 47m
1 stop
ORD8:37 pmChicago O'Hare Intl
May 27
ORD9:42 pmChicago O'Hare Intl
28h 07m
1 stop
ONT11:49 pmOntario
$261
Frontier
May 15
ONT8:06 pmOntario
24h 55m
1 stop
ORD11:01 pmChicago O'Hare Intl
May 17
ORD9:30 amChicago O'Hare Intl
11h 41m
1 stop
ONT7:11 pmOntario
$263
Frontier
Apr 2
ONT10:27 pmOntario
11h 23m
1 stop
ORD11:50 amChicago O'Hare Intl
Apr 11
ORD7:15 amChicago O'Hare Intl
13h 30m
1 stop
ONT6:45 pmOntario
$265

momondo Fare Finder

 
Customize your flight search to find flights from Ontario to Chicago O'Hare Intl Airport 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, momondo users made 832,500 searches. Data last updated March 26, 2026.
Use the filters below to find and compare flights from Ontario to Chicago O'Hare Intl Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 5/21

10:50 am-8:37 pm

1 stop7h 47m

Chicago O'Hare Intl

Wed 5/27

9:42 pm-11:49 pm

1 stop28h 07m

$261

OntarioChicago

ONT - ORD

ONTORD

Ontario

Mon 5/18

8:06 pm-11:01 pm

1 stop24h 55m

Chicago O'Hare Intl

Wed 5/20

4:05 pm-7:35 am

1 stop17h 30m

$266

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 5/28

10:50 am-8:37 pm

1 stop7h 47m

Chicago O'Hare Intl

Thu 6/4

9:42 pm-3:09 pm

2 stops19h 27m

$267

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 4/15

12:59 am-9:50 am

1 stop6h 51m

Chicago O'Hare Intl

Sat 4/18

8:55 am-11:55 pm

2 stops17h 00m

$269
Quickest round-trip

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 4/16

7:49 pm-6:08 am

1 stop8h 19m

Chicago O'Hare Intl

Fri 4/17

6:14 pm-11:58 pm

1 stop7h 44m

$270

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 4/15

7:44 pm-6:08 am

1 stop8h 24m

Chicago O'Hare Intl

Sun 4/19

6:09 pm-11:56 pm

1 stop7h 47m

$271

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 4/30

9:20 pm-6:08 am

1 stop6h 48m

Chicago O'Hare Intl

Thu 5/7

9:30 am-7:11 pm

1 stop11h 41m

$272

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 5/14

8:06 pm-3:43 pm

1 stop17h 37m

Chicago O'Hare Intl

Mon 5/18

9:42 pm-10:05 am

1 stop14h 23m

$273

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 4/7

9:26 pm-12:24 pm

2 stops36h 58m

Chicago O'Hare Intl

Sat 4/18

3:23 pm-10:37 pm

1 stop9h 14m

$274

OntarioChicago

ONT - ORD

ONTORD

Ontario

Mon 4/13

9:02 pm-6:20 am

1 stop7h 18m

Chicago O'Hare Intl

Thu 4/16

4:28 pm-4:38 pm

2 stops26h 10m

$275

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Chicago from

How to get the cheapest flight ticket from Ontario to Chicago O'Hare Intl Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Ontario and Chicago O'Hare Intl Airport?

What is the cheapest month to fly to Chicago O'Hare Intl Airport?

The month of September is another great option to travel to Chicago O'Hare Intl Airport, with average flight prices from Ontario averaging around $327.

What is the cheapest day to depart on your flight to Chicago O'Hare Intl Airport?

The cheapest day to depart on your flight to Chicago O'Hare Intl Airport is on a Thursday when prices can be found for as low as $355. This is often the case because there is less demand to fly during this day of the week. On the other hand, Sunday is the most expensive day to depart from Ontario because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $435.

What is the cheapest time of day to depart on your flight to Chicago O'Hare Intl Airport?

Flying to Chicago O'Hare Intl Airport from Ontario in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $277 when looking at flights departing in the afternoon. Try not to purchase tickets at noon because they tend to be around $464. Of course, these prices can vary depending on the time of year and what airport you fly to.

What is the cheapest Ontario to Chicago O'Hare Intl flight route?

Fly from Ontario to Chicago O'Hare Intl for the best Ontario - Chicago O'Hare Intl flight prices

How far in advance should I book a flight to Chicago O'Hare Intl Airport?

You are more likely to see cheaper flights to Chicago O'Hare Intl Airport from Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to Chicago O'Hare Intl Airport for around $395 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Chicago O'Hare Intl Airport from Ontario for as low as $297 on momondo.

What cabin class options are available on Ontario to Chicago O'Hare Intl flights?

There are 4 cabin classes available to choose from on Ontario to Chicago O'Hare Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Ontario to Chicago O'Hare Intl Airport flights?

You could potentially save up to 42% on your flight if you consider stops on a Ontario to Chicago O'Hare Intl Airport flight.

How have Ontario to Chicago O'Hare Intl Airport flight prices changed over time?

As of March 2026, prices for Ontario to Chicago O'Hare Intl Airport flights are approximately 6% more expensive when compared to flights at the same time last year.

When to book flights from Ontario to Chicago O'Hare Intl Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to Chicago O'Hare Intl Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Ontario to Chicago O'Hare Intl Airport (ONT to ORD) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to Chicago O'Hare Intl Airport

Best Price Found

$232

Fastest flight time

3h 58m

Direct flights

Every day
The best one-way flight to Chicago O'Hare Intl Airport from Ontario in the past 72 hours is $232. The best round-trip flight deal from Ontario to Chicago O'Hare Intl Airport found on momondo in the last 72 hours is $354.
The fastest flight from Ontario to Chicago O'Hare Intl Airport takes 3h 58m
Direct flights go from Ontario to Chicago O'Hare Intl Airport every day.
Search flight deals

  • How far is Ontario to Chicago O'Hare Intl by plane?

    Chicago O'Hare Intl is 1697.7 mi away from Ontario. In terms of flight time, this usually takes a little over 3h 58m.

  • When did momondo last update prices for flights from Ontario Airport to Chicago O'Hare Intl Airport?

    Prices for flights from Ontario Airport to Chicago O'Hare Intl Airport are updated daily.

  • How many operators does momondo search for flights from Ontario Airport to Chicago O'Hare Intl Airport?

  • How old do you have to be to fly from Ontario Airport to Chicago O'Hare Intl Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario Airport to Chicago O'Hare Intl Airport.

  • What documentation or ID do you need to fly to Chicago O'Hare Intl Airport?

    The necessary travel and health documents for your Chicago O'Hare Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Ontario to Chicago O'Hare Intl Airport?

  • What is the most popular airline from Ontario to Chicago O'Hare Intl Airport?

Best airlines flying from Ontario to Chicago O'Hare Intl Airport

Compare and see reviews for airlines that fly from Ontario to Chicago O'Hare Intl Airport with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $98Free CancellationRating
5.7
3,015 reviews
Search Frontier flights
United AirlinesPriceFrom $226Free CancellationRating
7.4
9,484 reviews
Search United Airlines flights
SouthwestPriceFrom $246Free CancellationRating
8.0
4,333 reviews
Search Southwest flights
American AirlinesPriceFrom $246Free CancellationRating
7.1
11,495 reviews
Search American Airlines flights
DeltaPriceFrom $256Free CancellationRating
7.9
8,331 reviews
Search Delta flights

  • United Airlines Flights From Ontario to Chicago O'Hare Intl Airport

    The lowest priced United Airlines flight from Ontario to Chicago O'Hare Intl Airport from the last 72 hours was $226. Generally, United Airlines has 2 flights on this route every week with an average price of $414. United Airlines is rated 7.4/10 by our users.

Traveling to a place near Chicago?

Book flights to Chicago if you plan to visit one of these locations
Lake Geneva
Schaumburg
South Haven
Rockford
Merrillville
Gurnee
Rosemont
Naperville
New Buffalo
Orland Park
Kenosha
Oak Brook
Joliet
Janesville
Racine
Hammond
Aurora
Elgin
Tinley Park
South Holland

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to Chicago?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Chicago from Ontario.

Can I find flights from Ontario to Chicago with flexible booking policies on momondo?

All flight searches from Ontario to Chicago on momondo can be filtered to show those which offer flexible booking policies.

How can momondo help me find flights from Ontario to Chicago?

Once all potential Ontario to Chicago flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

I’m not ready to book a flight from Ontario to Chicago right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Chicago, momondo offers a useful price alert feature which will track prices for flights to Chicago from Ontario and alert you when they change.

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