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 8/28. 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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Cheap round-trip flights

Frontier Logo
12:04 pm - 12:01 amONT-ORD
9h 57m1 stop
Frontier Logo
7:00 am - 8:45 amORD-ONT
27h 45m1 stop
$236Frontier
Find Deal
Sat, Aug 23 - Sat, Aug 30
Frontier Logo
12:04 pm - 12:01 amONT-ORD
9h 57m1 stop
Frontier Logo
7:00 am - 11:50 pmORD-ONT
18h 50m1 stop
$237Frontier
Find Deal
Sat, Aug 23 - Sat, Aug 30
Frontier Logo
12:59 am - 9:42 pmONT-ORD
18h 43m1 stop
Frontier Logo
7:20 am - 11:50 pmORD-ONT
18h 30m1 stop
$238Frontier
Find Deal
Tue, Aug 26 - Tue, Sep 2
Frontier Logo
12:59 am - 12:32 amONT-ORD
21h 33m1 stop
Frontier Logo
9:55 am - 7:14 pmORD-ONT
11h 19m1 stop
$239Frontier
Find Deal
Tue, Aug 12 - Sat, Aug 16
American Airlines Logo
6:17 am - 6:17 pmONT-ORD
10h 00m1 stop
American Airlines Logo
8:00 am - 4:24 pmORD-ONT
10h 24m1 stop
$274American Airlines
Find Deal
Tue, Aug 26 - Sat, Aug 30
American Airlines Logo
1:00 pm - 12:30 amONT-ORD
9h 30m1 stop
American Airlines Logo
10:41 am - 6:35 pmORD-ONT
9h 54m1 stop
$283American Airlines
Find Deal
Tue, Oct 14 - Tue, Oct 21
Delta Logo
7:05 am - 4:28 pmONT-ORD
7h 23m1 stop
Delta Logo
6:24 pm - 10:40 pmORD-ONT
6h 16m1 stop
$305Delta
Find Deal
Sat, Aug 23 - Sat, Aug 30
Alaska Airlines Logo
11:39 am - 10:07 pmONT-ORD
8h 28m1 stop
Alaska Airlines Logo
8:00 am - 2:12 pmORD-ONT
8h 12m1 stop
$306Alaska Airlines
Find Deal
Tue, Sep 9 - Wed, Sep 10
Delta Logo
11:40 am - 11:51 pmONT-ORD
10h 11m1 stop
Delta Logo
1:00 pm - 10:42 pmORD-ONT
11h 42m2 stops
$312Delta
Find Deal
Wed, Sep 3 - Wed, Sep 10
Alaska Airlines Logo
1:31 pm - 11:59 pmONT-ORD
8h 28m1 stop
Alaska Airlines Logo
3:15 pm - 12:03 amORD-ONT
10h 48m1 stop
$316Alaska Airlines
Find Deal
Tue, Oct 7 - Thu, Oct 9

American Airlines flights from Ontario to Chicago O'Hare Intl Airport

Our best American Airlines deals on Ontario to Chicago O'Hare Intl Airport flight tickets
American Airlines
Aug 26
ONT6:17 amOntario
10h 00m
1 stop
ORD6:17 pmChicago O'Hare Intl
Aug 30
ORD8:00 amChicago O'Hare Intl
10h 24m
1 stop
ONT4:24 pmOntario
American Airlines
Oct 14
ONT1:00 pmOntario
9h 30m
1 stop
ORD12:30 amChicago O'Hare Intl
Oct 21
ORD10:41 amChicago O'Hare Intl
9h 54m
1 stop
ONT6:35 pmOntario
American Airlines
Sep 2
ONT6:17 amOntario
10h 00m
1 stop
ORD6:17 pmChicago O'Hare Intl
Sep 5
ORD8:25 pmChicago O'Hare Intl
14h 56m
1 stop
ONT9:21 amOntario

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
Aug 23
ONT12:04 pmOntario
9h 57m
1 stop
ORD12:01 amChicago O'Hare Intl
Aug 30
ORD7:00 amChicago O'Hare Intl
27h 45m
1 stop
ONT8:45 amOntario
Frontier
Aug 23
ONT12:04 pmOntario
9h 57m
1 stop
ORD12:01 amChicago O'Hare Intl
Aug 30
ORD7:00 amChicago O'Hare Intl
18h 50m
1 stop
ONT11:50 pmOntario
Frontier
Aug 26
ONT12:59 amOntario
18h 43m
1 stop
ORD9:42 pmChicago O'Hare Intl
Sep 2
ORD7:20 amChicago O'Hare Intl
18h 30m
1 stop
ONT11:50 pmOntario

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 July 31, 2025.
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

OntarioChicago

ONT - ORD

ONTORD

Ontario

Sat 8/23

12:04 pm-12:01 am

1 stop9h 57m

Chicago O'Hare Intl

Sat 8/30

7:00 am-8:45 am

1 stop27h 45m

$236

OntarioChicago

ONT - ORD

ONTORD

Ontario

Sat 8/23

12:04 pm-12:01 am

1 stop9h 57m

Chicago O'Hare Intl

Sat 8/30

7:00 am-11:50 pm

1 stop18h 50m

$237

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 8/26

12:59 am-9:42 pm

1 stop18h 43m

Chicago O'Hare Intl

Tue 9/2

7:20 am-11:50 pm

1 stop18h 30m

$238

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 8/12

12:59 am-12:32 am

1 stop21h 33m

Chicago O'Hare Intl

Sat 8/16

9:55 am-7:14 pm

1 stop11h 19m

$239

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 8/26

6:17 am-6:17 pm

1 stop10h 00m

Chicago O'Hare Intl

Sat 8/30

8:00 am-4:24 pm

1 stop10h 24m

$274

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 10/14

1:00 pm-12:30 am

1 stop9h 30m

Chicago O'Hare Intl

Tue 10/21

10:41 am-6:35 pm

1 stop9h 54m

$283

OntarioChicago

ONT - ORD

ONTORD

Ontario

Sat 8/23

7:05 am-4:28 pm

1 stop7h 23m

Chicago O'Hare Intl

Sat 8/30

6:24 pm-10:40 pm

1 stop6h 16m

$305

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 9/9

11:39 am-10:07 pm

1 stop8h 28m

Chicago O'Hare Intl

Wed 9/10

8:00 am-2:12 pm

1 stop8h 12m

$306

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 9/3

11:40 am-11:51 pm

1 stop10h 11m

Chicago O'Hare Intl

Wed 9/10

1:00 pm-10:42 pm

2 stops11h 42m

$312

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 10/7

1:31 pm-11:59 pm

1 stop8h 28m

Chicago O'Hare Intl

Thu 10/9

3:15 pm-12:03 am

1 stop10h 48m

$316

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 October is another great option to travel to Chicago O'Hare Intl Airport, with average flight prices from Ontario averaging around $250.

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 $358. 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 $457.

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 $284 when looking at flights departing in the afternoon. Try not to purchase tickets at noon because they tend to be around $439. 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 $364 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 $258 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?

No. A direct flight is the cheapest option for a flight between Ontario to Chicago O'Hare Intl Airport.

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

As of July 2025, 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

$108

Fastest flight time

5h 51m

Direct flights

Every day
The best one-way flight to Chicago O'Hare Intl Airport from Ontario in the past 72 hours is $108. The best round-trip flight deal from Ontario to Chicago O'Hare Intl Airport found on momondo in the last 72 hours is $236.
The fastest flight from Ontario to Chicago O'Hare Intl Airport takes 5h 51m
Direct flights go from Ontario to Chicago O'Hare Intl Airport every day.

  • 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 5h 51m.

  • 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
Spirit AirlinesPriceFrom $99Free CancellationRating
6.3
8,049 reviews
Search Spirit Airlines flights
FrontierPriceFrom $108Free CancellationRating
5.9
3,239 reviews
Search Frontier flights
United AirlinesPriceFrom $227Free CancellationRating
7.4
8,900 reviews
Search United Airlines flights
DeltaPriceFrom $241Free CancellationRating
8.0
7,981 reviews
Search Delta flights
American AirlinesPriceFrom $246Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
SouthwestPriceFrom $251Free CancellationRating
8.0
4,246 reviews
Search Southwest 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 $227. Generally, United Airlines has 6 flights on this route every week with an average price of $377. 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
Rockford
Schaumburg
South Haven
Merrillville
Gurnee
Naperville
Rosemont
Kenosha
New Buffalo
Joliet
Oak Brook
Racine
Hammond
Tinley Park
Elgin
Orland Park
Aurora
Janesville
Benton Harbor

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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1 adult
Tue 8/5
Tue 8/12

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