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

Flying on Frontier is currently your cheapest option to Ontario, with prices starting at $208. Additional round-trip tickets that might be worth considering are offered by United Airlines and Southwest, with the lowest prices starting at $237 and $237, respectively. Frontier is currently priced 27% below the average price you’ll pay for this route.

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

To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $105. United Airlines flights start at $114 while deals on Southwest start at $114 one-way.

What are the cheapest flights from Chicago to Ontario?

While on average a flight from Chicago to Ontario is generally $238, our data shows the cheapest flight currently is $113. When looking at the most popular route, (Chicago O'Hare Intl - Ontario), you can expect to pay $218 for that flight.

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

Before booking your flight from Chicago to Ontario check out the most popular airlines for this route: American Airlines, Delta or Frontier.

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

Friday is generally a great day to depart. Flying on this day could help you save up to 33%.

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

Find a great deal and save up to 73% by booking at least 55 days prior to your desired departure date, rather than waiting until the week of travel. According to our data, there are a number of flights available from Chicago to Ontario within the next two weeks, with the cheapest ticket starting at $306.

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

Due to multiple factors, expect to potentially pay more when booking in December. For low rates, September can be a great choice for travel to Ontario. Flights to Ontario from Chicago in September are about $283 on average during September, but can be found for as low as $86.

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

Most trusted provider : When it comes to deals on Chicago-Ontario flights, Cheapflights users trust CheapOair the most. CheapOair 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 Chicago-Ontario flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

Ontario (ONT) is the airport you will fly into if you book a flight from Chicago to Ontario. You should not have trouble finding flights to Ontario from Chicago; the airport handles an average of 0 inbound flights from Chicago per day. You should also have plenty of airline options to choose from since 5 airlines have flights to the Ontario airport from Chicago. It is only a 3.1 mi journey from Ontario (ONT) to Ontario’s city center.

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

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

How can I find direct flights from Chicago to Ontario?

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

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

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

$105+ Flights from Chicago to Ontario

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Find cheap flights from Chicago to Ontario 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.

Cheapflights Tip: The best prices from Chicago to Ontario are usually found in November or September, booked 40 days in advance, depart on a Saturday or Thursday and return on a Tuesday

Cheap flight deals from Chicago to Ontario

Most accurate provider	CheapOair 3 stars
Most trusted provider	CheapOair 3 stars
Round-trip from	$208 (Booking.com)
One-way from	$105 (Trip.com)
Popular in	December
Cheapest in	November
Average price	$272
Good round-trip deal	$264 or less
Good one-way deal	$113 or less

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

Search Deals

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

Search Deals

From Chicago (CHI) to Ontario

Search Deals

One-way flight from Chicago (CHI) to Ontario

Search Deals

High demand for flights, 0% potential price rise

Search Deals

Cheapest flight prices on average. 4% potential price decrease ($13 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in May 2025

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

Search Deals

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

Search Deals

Find flight deals from Chicago to Ontario

Cheapest flights from Chicago to Ontario
Explore the most affordable flight options available from Chicago to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 1, 2025.

Wed 5/286:00 amORD - ONT

1 stop29h 15mFrontier

Fri 5/3012:59 amONT - ORD

1 stop20h 53mFrontier

Deal found 4/30

$208

Thu 5/292:44 pmMDW - ONT

1 stop20h 31mFrontier

Wed 6/45:21 pmONT - MDW

1 stop25h 32mFrontier

Deal found 4/29

$209

Thu 6/57:55 pmORD - ONT

Nonstop4h 31mUnited Airlines

Wed 6/116:41 pmONT - ORD

1 stop8h 48mUnited Airlines

Deal found 4/30

$237

Sun 6/18:30 pmMDW - ONT

Nonstop4h 15mSouthwest

Mon 6/22:55 pmONT - MDW

1 stop5h 55mSouthwest

Deal found 4/29

$237

Tue 9/96:20 amORD - ONT

1 stop9h 49mAlaska Airlines

Sat 11/86:55 pmONT - ORD

1 stop8h 09mAlaska Airlines

Deal found 4/30

$246

Sat 6/144:56 pmORD - ONT

1 stop9h 03mAmerican Airlines

Tue 7/112:55 pmONT - ORD

1 stop7h 36mAmerican Airlines

Deal found 4/30

$247

Sat 9/131:16 pmORD - ONT

1 stop8h 26mDelta

Tue 11/410:59 pmONT - ORD

1 stop7h 35mDelta

Deal found 4/30

$257

Sat 6/149:24 amMDW - ONT

2 stops8h 53mDelta

Tue 6/1710:05 pmONT - MDW

1 stop9h 36mDelta

Deal found 4/28

$262

Thu 8/216:20 amORD - ONT

1 stop9h 49mHawaiian Airlines

Mon 8/2511:39 amONT - ORD

1 stop10h 20mHawaiian Airlines

Deal found 4/30

$286

Tue 5/62:07 pmORD - ONT

1 stop11h 51mMultiple Airlines

Fri 5/912:16 pmONT - ORD

1 stop9h 25mMultiple Airlines

Deal found 4/29

$348

Best flights from Chicago to Ontario
Discover carefully curated flight deals from Chicago to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated May 1, 2025.

Wed 5/286:00 amORD - ONT

1 stop29h 15mFrontier

Fri 5/3012:59 amONT - ORD

1 stop20h 53mFrontier

Deal found 4/30

$208

Thu 6/57:55 pmORD - ONT

Nonstop4h 31mUnited Airlines

Wed 6/116:41 pmONT - ORD

1 stop8h 48mUnited Airlines

Deal found 4/30

$237

Sun 6/18:30 pmMDW - ONT

Nonstop4h 15mSouthwest

Mon 6/22:55 pmONT - MDW

1 stop5h 55mSouthwest

Deal found 4/29

$237

Tue 9/96:20 amORD - ONT

1 stop9h 49mAlaska Airlines

Sat 11/86:55 pmONT - ORD

1 stop8h 09mAlaska Airlines

Deal found 4/30

$246

Sat 6/145:36 pmORD - ONT

1 stop8h 23mAmerican Airlines

Fri 6/2012:59 amONT - ORD

1 stop7h 11mAmerican Airlines

Deal found 4/30

$247

Sat 9/131:16 pmORD - ONT

1 stop8h 26mDelta

Tue 11/410:59 pmONT - ORD

1 stop7h 35mDelta

Deal found 4/30

$257

Thu 8/216:20 amORD - ONT

1 stop9h 49mHawaiian Airlines

Mon 8/2511:39 amONT - ORD

1 stop10h 20mHawaiian Airlines

Deal found 4/30

$286

Thu 5/292:44 pmMDW - ONT

1 stop20h 31mFrontier

Wed 6/45:21 pmONT - MDW

1 stop25h 32mFrontier

Deal found 4/29

$209

Sat 6/149:24 amMDW - ONT

2 stops8h 53mDelta

Tue 6/1710:05 pmONT - MDW

1 stop9h 36mDelta

Deal found 4/28

$262

Last-minute flights from Chicago to Ontario
Discover last-minute flight deals from Chicago to Ontario. Data last updated May 1, 2025 and is based on user searches.

Mon 5/512:15 pmORD - ONT

2 stops12h 28mDelta

Tue 5/1311:44 amONT - ORD

1 stop10h 15mDelta

Deal found 4/29

$492

Tue 5/64:59 pmMDW - ONT

1 stop7h 37mDelta

Mon 5/1210:00 pmONT - MDW

1 stop9h 40mDelta

Deal found 4/29

$519

Tue 5/68:00 pmMDW - ONT

Nonstop4h 15mSouthwest

Wed 5/146:00 amONT - MDW

Nonstop3h 50mSouthwest

Deal found 4/29

$856

Wed 5/72:07 pmORD - ONT

1 stop11h 51mMultiple Airlines

Sun 5/116:47 pmONT - ORD

1 stop10h 58mMultiple Airlines

Deal found 4/29

$328

Wed 5/712:00 pmORD - ONT

1 stop10h 29mHawaiian Airlines

Sun 5/116:00 amONT - ORD

1 stop9h 00mHawaiian Airlines

Deal found 4/30

$464

Thu 5/88:03 pmMDW - ONT

1 stop5h 56mFrontier

Sat 5/101:15 pmONT - MDW

1 stop23h 33mFrontier

Deal found 4/28

$211

Thu 5/87:00 amORD - ONT

1 stop12h 57mFrontier

Mon 5/122:28 pmONT - ORD

1 stop12h 42mFrontier

Deal found 4/30

$218

Thu 5/82:07 pmORD - ONT

1 stop11h 51mAlaska Airlines

Wed 5/2111:51 amONT - ORD

1 stop10h 08mAlaska Airlines

Deal found 4/29

$349

Sat 5/108:45 amORD - ONT

1 stop7h 40mUnited Airlines

Sat 5/247:00 amONT - ORD

Nonstop3h 58mUnited Airlines

Deal found 4/29

$526

Sat 5/175:00 amORD - ONT

1 stop6h 50mAmerican Airlines

Fri 6/1312:59 amONT - ORD

1 stop7h 11mAmerican Airlines

Deal found 4/30

$383

Wed 5/286:00 amORD - ONT

1 stop29h 15mFrontier

Fri 5/3012:59 amONT - ORD

1 stop20h 53mFrontier

Deal found 4/29

$205

Wed 5/2810:00 amORD - ONT

1 stop7h 50mHawaiian Airlines

Mon 6/26:00 amONT - ORD

1 stop9h 02mHawaiian Airlines

Deal found 4/29

$335

One-way flights from Chicago to Ontario
Search for one-way flight options from Chicago to Ontario. Find affordable one-way fares based on user searches. Data last updated May 1, 2025.

Mon 6/169:56 pmORD - ONT

1 stop20h 22mFrontier

Deal found 4/30

$105

Mon 5/128:03 pmMDW - ONT

1 stop5h 56mFrontier

Deal found 4/30

$108

Sat 5/317:55 pmORD - ONT

Nonstop4h 31mUnited Airlines

Deal found 4/30

$114

Fri 6/612:35 pmMDW - ONT

Nonstop4h 10mSouthwest

Deal found 4/29

$114

Mon 7/215:25 pmORD - ONT

1 stop5h 45mSouthwest

Deal found 4/30

$119

Tue 6/108:00 amORD - ONT

1 stop9h 50mAlaska Airlines

Deal found 4/30

$123

Mon 6/167:20 pmORD - ONT

1 stop6h 26mDelta

Deal found 4/30

$129

Sat 6/149:24 amMDW - ONT

2 stops8h 53mDelta

Deal found 4/29

$134

Wed 6/118:05 amORD - ONT

2 stops12h 07mAmerican Airlines

Deal found 4/30

$200

Wed 5/1412:00 pmORD - ONT

1 stop10h 29mHawaiian Airlines

Deal found 4/30

$202

Wed 5/217:35 amORD - ONT

3 stops14h 59mMultiple Airlines

Deal found 4/30

$715

Cheapflights Fare Finder

Use the filters below to find and compare flights from Chicago to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Wed 5/28

6:00 am-9:15 am

1 stop29h 15m

Ontario

Fri 5/30

12:59 am-11:52 pm

1 stop20h 53m

$208

ChicagoOntario

MDW - ONT

MDWONT

Chicago Midway

Thu 5/29

2:44 pm-9:15 am

1 stop20h 31m

Ontario

Wed 6/4

5:21 pm-8:53 pm

1 stop25h 32m

$209

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Thu 6/5

7:55 pm-10:26 pm

Nonstop4h 31m

Ontario

Wed 6/11

6:41 pm-5:29 am

1 stop8h 48m

$237

ChicagoOntario

MDW - ONT

MDWONT

Chicago Midway

Sun 6/1

8:30 pm-10:45 pm

Nonstop4h 15m

Ontario

Mon 6/2

2:55 pm-10:50 pm

1 stop5h 55m

$237

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Tue 9/9

6:20 am-2:09 pm

1 stop9h 49m

Ontario

Sat 11/8

6:55 pm-5:04 am

1 stop8h 09m

$246

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Sat 6/14

5:36 pm-11:59 pm

1 stop8h 23m

Ontario

Fri 6/20

12:59 am-10:10 am

1 stop7h 11m

$247

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Sat 9/13

1:16 pm-7:42 pm

1 stop8h 26m

Ontario

Tue 11/4

10:59 pm-8:34 am

1 stop7h 35m

$257

ChicagoOntario

MDW - ONT

MDWONT

Chicago Midway

Sat 6/14

9:24 am-4:17 pm

2 stops8h 53m

Ontario

Tue 6/17

10:05 pm-9:41 am

1 stop9h 36m

$262

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Thu 8/21

6:20 am-2:09 pm

1 stop9h 49m

Ontario

Mon 8/25

11:39 am-11:59 pm

1 stop10h 20m

$286

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Mon 6/16

9:56 pm-4:18 pm

1 stop20h 22m

$105

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/30

Showing 1-10 of 20 results

Compare providers for flights from Chicago to Ontario

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

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy1 star	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*2 stars
eDreams	Price Accuracy3 stars	Trust Score*3 stars
Cheapfaremart	Price Accuracy-	Trust Score*1 star
CheapOair	Price Accuracy3 stars	Trust Score*3 stars
Mytrip	Price Accuracy3 stars	Trust Score*3 stars
Priceline	Price Accuracy2 stars	Trust Score*3 stars
JustAirTicket	Price Accuracy-	Trust Score*3 stars

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

Have a flexible travel schedule? Discover the best time to fly to Ontario from Chicago 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.

Cheapflights Insights

Everything you need to know about your flight from Chicago to Ontario

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

Booking 40 days in advance of your planned departure date is, on average, the best time to get cheap flights from Chicago to Ontario. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, August is the cheapest month in which you can book a flight from Chicago to Ontario (average of $246). Flying from Chicago to Ontario in March is currently the most expensive (average of $328). 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 CHI to ONT?

Unlike at noon, when flights are generally more expensive, you can save up to 30% on flights from Chicago to Ontario by exploring options for tickets in the evening.

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

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

Rainfall in Ontario by month

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

Reviews of airlines servicing Ontario

Peruse reviews from past customers who have flown with Alaska Airlines, Southwest and Delta from Chicago to Ontario to help guide your decision. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Alaska Airlines

8.0

Very good

9,968 reviews

Reviews

1 / 20

10.0

Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Alaska Airlines

8.0

Very good

9,968 reviews

Alaska Airlines

8.0

Very good

9,968 reviews

Reviews

1 / 20

10.0

Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Southwest

8.0

Very good

4,294 reviews

Alaska Airlines

8.0

Very good

9,968 reviews

Reviews

1 / 20

10.0

Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Delta

8.0

Very good

7,934 reviews

Alaska Airlines

8.0

Very good

9,968 reviews

Reviews

1 / 20

10.0

Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Hawaiian Airlines

7.9

Good

2,408 reviews

Alaska Airlines

8.0

Very good

9,968 reviews

Reviews

1 / 20

10.0

Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

United Airlines

7.4

Good

8,696 reviews

Alaska Airlines

8.0

Very good

9,968 reviews

Reviews

1 / 20

10.0

Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Related info for your journey

What airport do you fly into for flights to Ontario from Chicago?
Ontario (ONT) is the airport you will fly into if you book a flight from Chicago to Ontario. You should not have trouble finding flights to Ontario from Chicago; the airport handles an average of 0 inbound flights from Chicago per day. You should also have plenty of airline options to choose from since 5 airlines have flights to the Ontario airport from Chicago. It is only a 3.1 mi journey from Ontario (ONT) to Ontario’s city center.
What are the cheapest airlines flying from Chicago to Ontario round-trip?
Flying on Frontier is currently your cheapest option to Ontario, with prices starting at $208. Additional round-trip tickets that might be worth considering are offered by United Airlines and Southwest, with the lowest prices starting at $237 and $237, respectively. Frontier is currently priced 27% below the average price you’ll pay for this route.
What are the cheapest airlines to fly from Chicago to Ontario one-way?
To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $105. United Airlines flights start at $114 while deals on Southwest start at $114 one-way.
What are the cheapest flights from Chicago to Ontario?
While on average a flight from Chicago to Ontario is generally $238, our data shows the cheapest flight currently is $113. When looking at the most popular route, (Chicago O'Hare Intl - Ontario), you can expect to pay $218 for that flight.
Can I find deals for flights from Chicago to Ontario that include hotel bookings?
Yes. In addition to deals on Chicago to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Chicago to Ontario?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Chicago to Ontario.
Can I find deals for business class flights from Chicago to Ontario?
Yes. Cheapflights offers flight deals from Chicago to Ontario 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 Chicago to Ontario?
Currently, August is the cheapest month in which you can book a flight from Chicago to Ontario (average of $246). Flying from Chicago to Ontario in March is currently the most expensive (average of $328). 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

Browse thousands of different options on Cheapflights for your next trip

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Other flights to Ontario

Top 5 airlines flying from Chicago to Ontario

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$123	Average$207	FlexibilityNo cancel fee	On-time62%
American Airlines	Cheapest$231	Average$371	FlexibilityNo cancel fee	On-time71%
Delta	Cheapest$246	Average$450	FlexibilityNo cancel fee	On-timeN/A
United Airlines	Cheapest$246	Average$406	FlexibilityNo cancel fee	On-time69%
Southwest	Cheapest$256	Average$482	FlexibilityNo cancel fee	On-time63%

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$105+ Cheap flights from Chicago (CHI) to Ontario (ONT)

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 6/16. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Chicago to Ontario with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheapflights Tip: The best prices from Chicago to Ontario are usually found in November or September, booked 40 days in advance, depart on a Saturday or Thursday and return on a Tuesday

Cheap flight deals from Chicago to Ontario

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 Chicago to Ontario

Cheapest flights from Chicago to OntarioExplore the most affordable flight options available from Chicago to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 1, 2025.

Explore the most affordable flight options available from Chicago to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 1, 2025.

Cheapflights Fare Finder

Use the filters below to find and compare flights from Chicago to Ontario that are best for you.

Compare providers for flights from Chicago to Ontario

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 Chicago to Ontario in May.

Best time to book a flight from Chicago to Ontario

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

Cheapflights Insights

Everything you need to know about your flight from Chicago to Ontario

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

Use this chart to determine the optimal time to book a round-trip flight from Chicago to Ontario. Price data was last updated on April 25, 2025.

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

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

Find hourly flight availability from Chicago to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated May 1, 2025.

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

Use this chart to determine the cheapest time to fly round-trip from Chicago to Ontario. Price data was last updated on March 30, 2025.

Rainfall in Ontario by month

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

Temperature in Ontario by month

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

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated May 1, 2025.

Related info for your journey

Find useful and relevant information for your journey from Chicago to Ontario. 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 into for flights to Ontario from Chicago?

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

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

What are the cheapest flights from Chicago to Ontario?

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

How can I find direct flights from Chicago to Ontario?

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

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

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Alternative routes for Chicago to Ontario

See prices for flight routes from nearby airports that may be better suited for you.

Top 5 airlines flying from Chicago to Ontario

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Cheapest flights from Chicago to Ontario
Explore the most affordable flight options available from Chicago to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 1, 2025.