What are the cheapest airlines flying from Ontario to Chicago round-trip?

Cheapflights users have booked flights from Ontario to Chicago round-trip from $135. Other airlines that can offer you cheap pricing are United Airlines, from $227, and American Airlines, from $247. These flights start at 54% lower than the current average price 3 months from now.

What are the cheapest airlines to fly from Ontario to Chicago one-way?

The cheapest airlines for a one-way flight from Ontario to Chicago are Frontier ($38), United Airlines ($114), and Delta ($129).

What are the most popular routes from Ontario to Chicago?

Most travelers choose Ontario - Chicago O'Hare Intl, Ontario - Chicago Midway or Ontario - Chicago Greater Rockford when deciding on the best route from Ontario to Chicago.

What are the cheapest flights from Ontario to Chicago?

On average you can expect to pay $245 for a flight from Ontario to Chicago. The cheapest flight overall is $113 while the most popular route, (Ontario - Chicago O'Hare Intl) is currently priced at $125.

What are the most popular airlines that fly from Ontario to Chicago?

American Airlines, Alaska Airlines and Delta are the most popular airlines when flying from Ontario to Chicago.

What is the cheapest day to fly round-trip from Ontario to Chicago?

Departing on a Tuesday is a good option for securing a great price. You can expect to save up to 19% when planning your travel around this day of the week.

How far in advance should I book a flight from Ontario to Chicago?

When searching for a good deal, it’s best to be prepared for potential fluctuations in price. We recommend booking at least 31 days in advance, which can save you up to 74% on flights from Ontario to Chicago compared to booking the week you need them. Waiting 31 days out may not be for everyone, so we have options available for flights within the next two weeks, with the lowest price starting at $327. For sooner than that we have options available in the next 3 days from $513.

What is the cheapest month to fly from Ontario to Chicago?

Due to multiple factors, expect to potentially pay more when booking in March. For low rates, October can be a great choice for travel to Chicago. Flights to Chicago from Ontario in October are about $311 on average during October, but can be found for as low as $98.

Most accurate provider : When it comes to deals on Ontario-Chicago flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-Chicago flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-Chicago flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on Ontario-Chicago flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-Chicago flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

What airport do you fly from for flights from Ontario to Chicago?

Ontario (ONT) is the airport you will fly out of if you book a flight from Ontario to Chicago. You should not have trouble finding flights to Chicago from Ontario; the airport handles an average of 0 outbound flights to Chicago per day. You should also have plenty of airline options to choose from since 7 airlines have flights from the Ontario airport to Chicago. It is only a 3.1 mi journey to Ontario (ONT) from Ontario’s city center.

Can I find deals for flights from Ontario to Chicago that include hotel bookings?

Yes. In addition to deals on Ontario to Chicago flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Ontario to Chicago?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to Chicago.

Can I find deals for business class flights from Ontario to Chicago?

Yes. Cheapflights offers flight deals from Ontario to Chicago by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$38+ Flights from Ontario to Chicago

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Find cheap flights from Ontario to Chicago with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

The best prices from Ontario to Chicago are usually found in November or September, booked 88 days in advance, depart on a Wednesday or Friday and return on a Monday

Cheap flight deals from Ontario to Chicago

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 3 stars
Round-trip from	$135 (Booking.com)
One-way from	$38 (Trip.com)
Popular in	January
Cheapest in	November
Average price	$319
Good round-trip deal	$269 or less
Good one-way deal	$158 or less

Provider with most accurate pricing for Ontario-Chicago (CHI) flight deals.

Search Deals

Provider most trusted by Cheapflights users for Ontario-Chicago (CHI) flights.

Search Deals

From Ontario to Chicago (CHI)

Search Deals

One-way flight from Ontario to Chicago (CHI)

Search Deals

Highest demand for flights based on searches. 15% potential increase in price ($55 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 2% potential price decrease ($7 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in February 2025

Search Deals

Price to beat on a round-trip flight from Ontario to Chicago (CHI).

Search Deals

Price to beat on a one-way flight from Ontario to Chicago (CHI).

Search Deals

Find flight deals from Ontario to Chicago

Cheapest flights from Ontario to Chicago
Explore the most affordable flight options available from Ontario to Chicago. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2025.

Fri 3/712:59 amONT - MDW

1 stop21h 18mFrontier

Tue 3/117:50 amMDW - ONT

1 stop12h 09mFrontier

Deal found 2/19

$135

Fri 3/712:59 amONT - ORD

1 stop10h 21mFrontier

Tue 3/116:45 amORD - ONT

1 stop19h 19mFrontier

Deal found 2/19

$135

Sat 6/217:00 amONT - ORD

Nonstop3h 58mUnited Airlines

Tue 6/248:20 pmORD - ONT

Nonstop4h 31mUnited Airlines

Deal found 2/18

$227

Tue 5/611:46 amONT - ORD

1 stop10h 13mMultiple Airlines

Thu 5/87:00 amORD - ONT

1 stop12h 47mMultiple Airlines

Deal found 2/19

$229

Tue 5/612:46 pmONT - ORD

1 stop6h 23mAmerican Airlines

Sat 5/107:00 amORD - ONT

1 stop6h 54mAmerican Airlines

Deal found 2/19

$247

Fri 4/253:15 pmONT - MDW

1 stop7h 15mSouthwest

Mon 4/287:05 pmMDW - ONT

1 stop5h 55mSouthwest

Deal found 2/19

$252

Tue 4/2210:15 pmONT - MDW

1 stop8h 52mDelta

Tue 4/2912:48 pmMDW - ONT

1 stop8h 40mDelta

Deal found 2/20

$257

Wed 4/235:15 pmONT - ORD

1 stop5h 38mDelta

Mon 4/287:50 amORD - ONT

1 stop8h 05mDelta

Deal found 2/20

$257

Thu 10/3011:30 amONT - ORD

1 stop10h 29mAlaska Airlines

Thu 11/610:00 amORD - ONT

1 stop10h 17mAlaska Airlines

Deal found 2/19

$303

Best flights from Ontario to Chicago
Discover carefully curated flight deals from Ontario to Chicago that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 20, 2025.

Fri 3/712:59 amONT - ORD

1 stop10h 21mFrontier

Tue 3/116:45 amORD - ONT

1 stop19h 19mFrontier

Deal found 2/19

$135

Thu 4/246:24 pmONT - ORD

1 stop9h 41mMultiple Airlines

Mon 4/2811:41 amORD - ONT

1 stop7h 43mMultiple Airlines

Deal found 2/19

$224

Sat 6/217:00 amONT - ORD

Nonstop3h 58mUnited Airlines

Tue 6/248:20 pmORD - ONT

Nonstop4h 31mUnited Airlines

Deal found 2/18

$227

Wed 3/267:35 pmONT - ORD

1 stop7h 33mAmerican Airlines

Sun 3/305:00 amORD - ONT

1 stop7h 07mAmerican Airlines

Deal found 2/19

$247

Tue 4/2210:15 pmONT - MDW

1 stop8h 52mDelta

Tue 4/2912:48 pmMDW - ONT

1 stop8h 40mDelta

Deal found 2/20

$257

Mon 3/104:39 pmONT - MDW

1 stop5h 38mFrontier

Wed 3/196:40 amMDW - ONT

1 stop19h 24mFrontier

Deal found 2/20

$136

Thu 4/245:10 amONT - MDW

Nonstop3h 50mSouthwest

Mon 4/287:05 pmMDW - ONT

1 stop5h 55mSouthwest

Deal found 2/19

$282

Thu 4/246:24 pmONT - ORD

1 stop9h 41mAlaska Airlines

Sat 4/266:00 amORD - ONT

1 stop16h 29mAlaska Airlines

Deal found 2/20

$291

Wed 4/235:15 pmONT - ORD

1 stop5h 38mDelta

Mon 4/287:50 amORD - ONT

1 stop8h 05mDelta

Deal found 2/20

$257

Sat 4/126:10 amONT - ORD

1 stop8h 15mSouthwest

Mon 4/1412:40 pmORD - ONT

2 stops9h 20mSouthwest

Deal found 2/19

$297

Last-minute flights from Ontario to Chicago
Discover last-minute flight deals from Ontario to Chicago. Data last updated February 20, 2025 and is based on user searches.

Tue 2/256:00 amONT - ORD

1 stop6h 55mUnited Airlines

Wed 2/262:00 pmORD - ONT

1 stop9h 59mUnited Airlines

Deal found 2/20

$610

Wed 2/264:09 pmONT - ORD

1 stop17h 45mFrontier

Wed 3/510:56 amORD - ONT

1 stop9h 02mFrontier

Deal found 2/19

$137

Thu 2/277:14 pmONT - ORD

1 stop8h 39mHawaiian Airlines

Sun 3/210:00 amORD - ONT

1 stop10h 19mHawaiian Airlines

Deal found 2/20

$680

Fri 2/2812:59 amONT - MDW

1 stop21h 18mFrontier

Tue 3/47:05 amMDW - ONT

1 stop18h 54mFrontier

Deal found 2/19

$142

Sat 3/16:00 amONT - ORD

2 stops9h 29mDelta

Wed 3/127:30 amORD - ONT

1 stop11h 12mDelta

Deal found 2/19

$396

Sat 3/18:29 pmONT - ORD

1 stop6h 36mMultiple Airlines

Tue 3/47:45 amORD - ONT

2 stops11h 14mMultiple Airlines

Deal found 2/19

$403

Sat 3/111:45 amONT - ORD

2 stops10h 14mAlaska Airlines

Mon 3/315:53 pmORD - ONT

1 stop8h 06mAlaska Airlines

Deal found 2/19

$510

Sat 3/11:05 pmONT - MDW

1 stop7h 15mDelta

Tue 3/45:05 pmMDW - ONT

1 stop7h 47mDelta

Deal found 2/19

$519

Sat 3/15:05 amONT - MDW

2 stops9h 05mSouthwest

Tue 3/410:05 amMDW - ONT

2 stops8h 55mSouthwest

Deal found 2/19

$529

Sat 3/16:50 amONT - ORD

2 stops10h 50mSouthwest

Tue 3/45:45 amORD - ONT

2 stops9h 40mSouthwest

Deal found 2/19

$529

Fri 3/712:59 amONT - MDW

1 stop21h 18mFrontier

Tue 3/117:50 amMDW - ONT

1 stop12h 09mFrontier

Deal found 2/19

$135

Fri 3/712:59 amONT - ORD

1 stop10h 21mFrontier

Tue 3/116:45 amORD - ONT

1 stop19h 19mFrontier

Deal found 2/19

$135

One-way flights from Ontario to Chicago
Search for one-way flight options from Ontario to Chicago. Find affordable one-way fares based on user searches. Data last updated February 20, 2025.

Tue 3/1812:59 amONT - MDW

1 stop21h 18mFrontier

Deal found 2/18

$38

Mon 3/1712:59 amONT - ORD

1 stop21h 24mFrontier

Deal found 2/19

$38

Fri 6/277:00 amONT - ORD

Nonstop4h 03mUnited Airlines

Deal found 2/20

$114

Tue 4/2210:15 pmONT - MDW

1 stop8h 52mDelta

Deal found 2/19

$129

Wed 4/1610:15 pmONT - ORD

2 stops9h 09mDelta

Deal found 2/19

$134

Tue 4/296:00 amONT - ORD

1 stop22h 05mAlaska Airlines

Deal found 2/20

$137

Wed 3/126:00 amONT - ORD

1 stop6h 01mAmerican Airlines

Deal found 2/19

$145

Thu 3/2011:35 amONT - MDW

Nonstop3h 45mSouthwest

Deal found 2/20

$159

Sat 6/286:20 amONT - ORD

1 stop6h 40mSouthwest

Deal found 2/19

$160

Tue 3/256:00 amONT - ORD

1 stop8h 53mHawaiian Airlines

Deal found 2/20

$187

Fri 5/1610:40 pmONT - ORD

1 stop11h 37mJetBlue

Deal found 2/19

$221

Find flights from Ontario to Chicago within your budget

Fly from

Fly to

Route

Depart

Return

Price

OntarioChicago

ONT - MDW

ONTMDW

Ontario

Fri 3/7

12:59 am-12:17 am

1 stop21h 18m

Chicago Midway

Tue 3/11

7:50 am-5:59 pm

1 stop12h 09m

$135

OntarioChicago

ONT - ORD

ONTORD

Ontario

Fri 3/7

12:59 am-1:20 pm

1 stop10h 21m

Chicago O'Hare Intl

Tue 3/11

6:45 am-12:04 am

1 stop19h 19m

$135

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 4/24

6:24 pm-6:05 am

1 stop9h 41m

Chicago O'Hare Intl

Mon 4/28

11:41 am-5:24 pm

1 stop7h 43m

$224

OntarioChicago

ONT - ORD

ONTORD

Ontario

Sat 6/21

7:00 am-12:58 pm

Nonstop3h 58m

Chicago O'Hare Intl

Tue 6/24

8:20 pm-10:51 pm

Nonstop4h 31m

$227

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 3/26

7:35 pm-5:08 am

1 stop7h 33m

Chicago O'Hare Intl

Sun 3/30

5:00 am-10:07 am

1 stop7h 07m

$247

OntarioChicago

ONT - MDW

ONTMDW

Ontario

Fri 4/25

3:15 pm-12:30 am

1 stop7h 15m

Chicago Midway

Mon 4/28

7:05 pm-11:00 pm

1 stop5h 55m

$252

OntarioChicago

ONT - MDW

ONTMDW

Ontario

Tue 4/22

10:15 pm-9:07 am

1 stop8h 52m

Chicago Midway

Tue 4/29

12:48 pm-7:28 pm

1 stop8h 40m

$257

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 4/23

5:15 pm-12:53 am

1 stop5h 38m

Chicago O'Hare Intl

Mon 4/28

7:50 am-1:55 pm

1 stop8h 05m

$257

OntarioChicago

ONT - ORD

ONTORD

Ontario

Thu 4/24

6:24 pm-6:05 am

1 stop9h 41m

Chicago O'Hare Intl

Sat 4/26

6:00 am-8:29 pm

1 stop16h 29m

$291

OntarioChicago

ONT - ORD

ONTORD

Ontario

Sat 4/12

6:10 am-4:25 pm

1 stop8h 15m

Chicago O'Hare Intl

Mon 4/14

12:40 pm-8:00 pm

2 stops9h 20m

$297

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/18

Showing 1-10 of 21 results

Compare providers for flights from Ontario to Chicago

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to Chicago in February.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy1 star	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*3 stars
Flightnetwork	Price Accuracy2 stars	Trust Score*3 stars
eDreams	Price Accuracy3 stars	Trust Score*3 stars
Cheapfaremart	Price Accuracy-	Trust Score*3 stars
AranGrant	Price Accuracy3 stars	Trust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

Most accurate provider: When it comes to deals on Ontario-Chicago flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-Chicago flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-Chicago flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on Ontario-Chicago flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-Chicago flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Ontario to Chicago

Have a flexible travel schedule? Discover the best time to fly to Chicago from Ontario with our price prediction graph.

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.

Travel insights for flights from Ontario to Chicago

Get recent, data-driven insights about flights from Ontario to Chicago including ideal travel times, pricing trends, and more.

How far ahead should I book a flight from Ontario to Chicago?

The best time to book flights from Ontario to Chicago is 88 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from Ontario to Chicago?

Currently, August is the cheapest month in which you can book a flight from Ontario to Chicago (average of $245). Flying from Ontario to Chicago in March is currently the most expensive (average of $321). 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 CHI?

Unlike at noon, when flights are generally more expensive, you can save up to 54% on flights from Ontario to Chicago by exploring options for tickets in the evening.

What is the cheapest day to fly from Ontario to Chicago?

Travelers seeking maximum savings on their Ontario to Chicago flight should consider departing on Saturday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Rainfall in Chicago by month

In terms of precipitation, rainfall in Chicago ranges from 1.7 - 4.9 inches per month. August is typically the wettest month, when rainfall can reach 4.9 in. January is typically the driest time to visit Chicago when rainfall is around 1.7 in.

Temperature in Chicago by month

If weather is an important factor for your trip to Chicago, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 23.0 F).

Reviews of airlines servicing Chicago

To help decide which airline to fly from Ontario to Chicago, see what other customers have to say about Southwest, Alaska Airlines and Delta. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Southwest

8.1

Very good

4,411 reviews

Reviews

1 / 20

10.0

Excellent

Arlene,May 2024

SAN - OAK

My original flight was delayed so they found this flight for me so I could arrive at a reasonable time

Southwest

8.1

Very good

4,411 reviews

Southwest

8.1

Very good

4,411 reviews

Reviews

1 / 20

10.0

Excellent

Arlene,May 2024

SAN - OAK

My original flight was delayed so they found this flight for me so I could arrive at a reasonable time

Alaska Airlines

8.0

Very good

9,697 reviews

Southwest

8.1

Very good

4,411 reviews

Reviews

1 / 20

10.0

Excellent

Arlene,May 2024

SAN - OAK

My original flight was delayed so they found this flight for me so I could arrive at a reasonable time

Delta

8.0

Very good

8,219 reviews

Southwest

8.1

Very good

4,411 reviews

Reviews

1 / 20

10.0

Excellent

Arlene,May 2024

SAN - OAK

My original flight was delayed so they found this flight for me so I could arrive at a reasonable time

Hawaiian Airlines

7.9

Good

2,317 reviews

Southwest

8.1

Very good

4,411 reviews

Reviews

1 / 20

10.0

Excellent

Arlene,May 2024

SAN - OAK

My original flight was delayed so they found this flight for me so I could arrive at a reasonable time

JetBlue

7.4

Good

3,070 reviews

Southwest

8.1

Very good

4,411 reviews

Reviews

1 / 20

10.0

Excellent

Arlene,May 2024

SAN - OAK

My original flight was delayed so they found this flight for me so I could arrive at a reasonable time

Related info for your journey

What airport do you fly from for flights from Ontario to Chicago?
Ontario (ONT) is the airport you will fly out of if you book a flight from Ontario to Chicago. You should not have trouble finding flights to Chicago from Ontario; the airport handles an average of 0 outbound flights to Chicago per day. You should also have plenty of airline options to choose from since 7 airlines have flights from the Ontario airport to Chicago. It is only a 3.1 mi journey to Ontario (ONT) from Ontario’s city center.
What are the cheapest airlines flying from Ontario to Chicago round-trip?
Cheapflights users have booked flights from Ontario to Chicago round-trip from $135. Other airlines that can offer you cheap pricing are United Airlines, from $227, and American Airlines, from $247. These flights start at 54% lower than the current average price 3 months from now.
What are the cheapest airlines to fly from Ontario to Chicago one-way?
The cheapest airlines for a one-way flight from Ontario to Chicago are Frontier ($38), United Airlines ($114), and Delta ($129).
What are the most popular routes from Ontario to Chicago?
Most travelers choose Ontario - Chicago O'Hare Intl, Ontario - Chicago Midway or Ontario - Chicago Greater Rockford when deciding on the best route from Ontario to Chicago.
What are the cheapest flights from Ontario to Chicago?
On average you can expect to pay $245 for a flight from Ontario to Chicago. The cheapest flight overall is $113 while the most popular route, (Ontario - Chicago O'Hare Intl) is currently priced at $125.
Can I find deals for flights from Ontario to Chicago that include hotel bookings?
Yes. In addition to deals on Ontario to Chicago flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Ontario to Chicago?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to Chicago.
Can I find deals for business class flights from Ontario to Chicago?
Yes. Cheapflights offers flight deals from Ontario to Chicago by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from Ontario to Chicago?
Currently, August is the cheapest month in which you can book a flight from Ontario to Chicago (average of $245). Flying from Ontario to Chicago in March is currently the most expensive (average of $321). 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.

See more FAQs

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Top 7 airlines flying from Ontario to Chicago

Airline	Cheapest	Average	Flexibility	On-time
Spirit Airlines	Cheapest$74	Average$177	FlexibilityNo cancel fee	On-time65%
Frontier	Cheapest$109	Average$191	FlexibilityNo cancel fee	On-time62%
Alaska Airlines	Cheapest$161	Average$438	FlexibilityNo cancel fee	On-time75%
Delta	Cheapest$236	Average$403	FlexibilityNo cancel fee	On-timeN/A
United Airlines	Cheapest$246	Average$455	FlexibilityNo cancel fee	On-time69%
American Airlines	Cheapest$246	Average$383	FlexibilityNo cancel fee	On-time71%
Southwest	Cheapest$307	Average$488	FlexibilityNo cancel fee	On-time63%

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$38+ Cheap flights from Ontario (ONT) to Chicago (CHI)

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 3/18. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Ontario to Chicago with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

The best prices from Ontario to Chicago are usually found in November or September, booked 88 days in advance, depart on a Wednesday or Friday and return on a Monday

Cheap flight deals from Ontario to Chicago

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Good round-trip deal

Good one-way deal

Find flight deals from Ontario to Chicago

Cheapest flights from Ontario to ChicagoExplore the most affordable flight options available from Ontario to Chicago. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2025.

Explore the most affordable flight options available from Ontario to Chicago. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2025.

Find flights from Ontario to Chicago within your budget

Compare providers for flights from Ontario to Chicago

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to Chicago in February.

Best time to book a flight from Ontario to Chicago

Have a flexible travel schedule? Discover the best time to fly to Chicago from Ontario with our price prediction graph.

Travel insights for flights from Ontario to Chicago

Get recent, data-driven insights about flights from Ontario to Chicago including ideal travel times, pricing trends, and more.

How far ahead should I book a flight from Ontario to Chicago?

Use this chart to determine the optimal time to book a round-trip flight from Ontario to Chicago. Price data was last updated on February 14, 2025.

What is the cheapest month to book a flight from Ontario to Chicago?

What is the cheapest time of day to fly from ONT to CHI?

Find hourly flight availability from Ontario to Chicago. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated February 20, 2025.

What is the cheapest day to fly from Ontario to Chicago?

Use this chart to determine the cheapest time to fly round-trip from Ontario to Chicago. Price data was last updated on February 16, 2025.

Rainfall in Chicago by month

Plan your trip to Chicago by taking into account the average rainfall totals by month.

Temperature in Chicago by month

Plan your trip to Chicago by taking into account the average temperature totals by month.

Reviews of airlines servicing Chicago

To help decide which airline to fly from Ontario to Chicago, see what other customers have to say about Southwest, Alaska Airlines and Delta. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from Ontario to Chicago. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

What airport do you fly from for flights from Ontario to Chicago?

What are the cheapest airlines flying from Ontario to Chicago round-trip?

What are the cheapest airlines to fly from Ontario to Chicago one-way?

What are the most popular routes from Ontario to Chicago?

What are the cheapest flights from Ontario to Chicago?

Can I find deals for flights from Ontario to Chicago that include hotel bookings?

How can I find direct flights from Ontario to Chicago?

Can I find deals for business class flights from Ontario to Chicago?

What is the cheapest month to book a flight from Ontario to Chicago?

Traveling to a place near Ontario?

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Alternative routes for Ontario to Chicago

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Top 7 airlines flying from Ontario to Chicago

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Cheapest flights from Ontario to Chicago
Explore the most affordable flight options available from Ontario to Chicago. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2025.