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Cheap flights from Ontario to Chicago from $108

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 8/1. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Ontario to Chicago

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
9:32 am - 12:49 am
ONT
-
ORD
13h 17m
1 stop
Frontier Logo
9:57 pm - 10:04 am
ORD
-
ONT
14h 07m
1 stop
$297Frontier
Tue, Jul 14 - Wed, Jul 15
United Airlines Logo
7:00 am - 1:10 pm
ONT
-
ORD
4h 10mnonstop
United Airlines Logo
8:06 pm - 10:35 pm
ORD
-
ONT
4h 29mnonstop
$298United Airlines
Thu, Aug 13 - Wed, Aug 19
Frontier Logo
3:40 pm - 5:37 am
ONT
-
ORD
11h 57m
1 stop
Frontier Logo
7:15 am - 3:14 pm
ORD
-
ONT
9h 59m
1 stop
$299Frontier
Thu, Jul 23 - Tue, Aug 4
Frontier Logo
10:49 am - 8:52 pm
ONT
-
ORD
8h 03m
1 stop
Frontier Logo
9:13 pm - 11:02 am
ORD
-
ONT
39h 49m
2 stops
$300Frontier
Wed, Aug 5 - Sat, Aug 8
Frontier Logo
3:40 pm - 5:37 am
ONT
-
ORD
11h 57m
1 stop
Frontier Logo
7:15 am - 3:14 pm
ORD
-
ONT
9h 59m
1 stop
$302Frontier
Wed, Jul 15 - Sat, Jul 18
Frontier Logo
9:36 am - 12:33 am
ONT
-
ORD
12h 57m
1 stop
Frontier Logo
9:20 am - 11:50 pm
ORD
-
ONT
16h 30m
2 stops
$303Frontier
Thu, Aug 6 - Wed, Aug 12
Frontier Logo
9:32 am - 12:49 am
ONT
-
ORD
13h 17m
1 stop
Frontier Logo
7:15 am - 12:53 pm
ORD
-
ONT
31h 38m
2 stops
$304Frontier
Tue, Jul 28 - Mon, Aug 3
Frontier Logo
1:38 pm - 5:37 am
ONT
-
ORD
13h 59m
1 stop
Frontier Logo
5:46 pm - 7:32 am
ORD
-
ONT
15h 46m
1 stop
$305Frontier
Tue, Jul 7 - Sat, Jul 18
United Airlines Logo
1:56 pm - 12:59 am
ONT
-
ORD
9h 03m
1 stop
United Airlines Logo
8:06 pm - 10:35 pm
ORD
-
ONT
4h 29mnonstop
$306United Airlines
Mon, Aug 17 - Wed, Aug 19
United Airlines Logo
7:13 pm - 5:59 am
ONT
-
ORD
8h 46m
1 stop
United Airlines Logo
8:06 pm - 10:35 pm
ORD
-
ONT
4h 29mnonstop
$307United Airlines
Thu, Aug 20 - Mon, Aug 24

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Delta flights from Ontario to Chicago O'Hare Intl Airport

Our best Delta deals on Ontario to Chicago O'Hare Intl Airport flight tickets
Delta
Aug 31
ONT11:56 amOntario
9h 33m
1 stop
ORD11:29 pmChicago O'Hare Intl
Sep 5
ORD6:00 amChicago O'Hare Intl
8h 16m
2 stops
ONT12:16 pmOntario
$293
Delta
Aug 20
ONT1:06 pmOntario
6h 24m
1 stop
ORD9:30 pmChicago O'Hare Intl
Aug 24
ORD2:00 pmChicago O'Hare Intl
10h 45m
2 stops
ONT10:45 pmOntario
$322
Delta
Aug 27
ONT11:56 amOntario
9h 33m
1 stop
ORD11:29 pmChicago O'Hare Intl
Sep 1
ORD8:48 amChicago O'Hare Intl
9h 36m
2 stops
ONT4:24 pmOntario
$324

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
Jul 17
ONT9:32 amOntario
13h 17m
1 stop
ORD12:49 amChicago O'Hare Intl
Jul 21
ORD9:57 pmChicago O'Hare Intl
14h 07m
1 stop
ONT10:04 amOntario
$284
Frontier
Jul 16
ONT3:40 pmOntario
11h 57m
1 stop
ORD5:37 amChicago O'Hare Intl
Jul 22
ORD5:46 pmChicago O'Hare Intl
15h 46m
1 stop
ONT7:32 amOntario
$290
Frontier
Sep 10
ONT9:12 pmOntario
12h 45m
1 stop
ORD11:57 amChicago O'Hare Intl
Sep 13
ORD10:40 pmChicago O'Hare Intl
14h 03m
1 stop
ONT10:43 amOntario
$294

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 June 23, 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

Tue 7/14

9:32 am-12:49 am

1 stop13h 17m

Chicago O'Hare Intl

Wed 7/15

9:57 pm-10:04 am

1 stop14h 07m

$297
Quickest round-trip

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 8/13

7:00 am-1:10 pm

Nonstop4h 10m

Chicago O'Hare Intl

Wed 8/19

8:06 pm-10:35 pm

Nonstop4h 29m

$298

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 7/23

3:40 pm-5:37 am

1 stop11h 57m

Chicago O'Hare Intl

Tue 8/4

7:15 am-3:14 pm

1 stop9h 59m

$299

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 8/5

10:49 am-8:52 pm

1 stop8h 03m

Chicago O'Hare Intl

Sat 8/8

9:13 pm-11:02 am

2 stops39h 49m

$300

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 7/15

3:40 pm-5:37 am

1 stop11h 57m

Chicago O'Hare Intl

Sat 7/18

7:15 am-3:14 pm

1 stop9h 59m

$302

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 8/6

9:36 am-12:33 am

1 stop12h 57m

Chicago O'Hare Intl

Wed 8/12

9:20 am-11:50 pm

2 stops16h 30m

$303

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 7/28

9:32 am-12:49 am

1 stop13h 17m

Chicago O'Hare Intl

Mon 8/3

7:15 am-12:53 pm

2 stops31h 38m

$304

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 7/7

1:38 pm-5:37 am

1 stop13h 59m

Chicago O'Hare Intl

Sat 7/18

5:46 pm-7:32 am

1 stop15h 46m

$305

OntarioChicago

ONT - ORD

ONTORD

Ontario

Mon 8/17

1:56 pm-12:59 am

1 stop9h 03m

Chicago O'Hare Intl

Wed 8/19

8:06 pm-10:35 pm

Nonstop4h 29m

$306

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 8/20

7:13 pm-5:59 am

1 stop8h 46m

Chicago O'Hare Intl

Mon 8/24

8:06 pm-10:35 pm

Nonstop4h 29m

$307

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 May is another great option to travel to Chicago O'Hare Intl Airport, with average flight prices from Ontario averaging around $373.

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 Wednesday when prices can be found for as low as $400. 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 $491.

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 $328 when looking at flights departing in the afternoon. Try not to purchase tickets at noon because they tend to be around $501. 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 from Ontario 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 $427 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 $345 on momondo.

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

There are 4 cabin classes available to choose from on Ontario to Chicago O'Hare Intl Airport 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 June 2026, prices for Ontario to Chicago O'Hare Intl Airport flights are approximately 17% cheaper 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

$218

Fastest flight time

4h 03m

Direct flights

Every day
The best one-way flight to Chicago O'Hare Intl Airport from Ontario in the past 72 hours is $218. The best round-trip flight deal from Ontario to Chicago O'Hare Intl Airport found on momondo in the last 72 hours is $420.
The fastest flight from Ontario to Chicago O'Hare Intl Airport takes 4h 03m
Direct flights go from Ontario to Chicago O'Hare Intl Airport every day.
Search flight deals

Frequently asked questions about flying from Ontario to Chicago O'Hare Intl Airport

  • 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 4h 03m.

  • 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 $117Free CancellationRating
5.6
2,870 reviews
Search Frontier flights
United AirlinesPriceFrom $258Free CancellationRating
7.4
9,875 reviews
Search United Airlines flights
SouthwestPriceFrom $258Free CancellationRating
7.9
4,242 reviews
Search Southwest flights
DeltaPriceFrom $260Free CancellationRating
7.8
8,424 reviews
Search Delta flights
American AirlinesPriceFrom $276Free CancellationRating
7.1
11,746 reviews
Search American Airlines 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 $258. Generally, United Airlines has 3 flights on this route every week with an average price of $456. 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
Orland Park
Oak Brook
New Buffalo
Joliet
Kenosha
Hammond
Aurora
Racine
Janesville
Elgin
Evanston
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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