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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 4/12. Fares are subject to change and may not be available on all flights or dates of travel.
CHI — ONT
Apr 2 — Apr 91
Wed 4/2
Wed 4/9
1 adult, Economy
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Cheapflights Tip: The best prices from Chicago to Ontario are usually found in November or September, booked 40 days in advance, depart on a Thursday or Saturday and return on a Tuesday

Cheap flight deals from Chicago to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Chicago (CHI) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated March 28, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$227
(United Airlines)

One-way from

$105
(Trip.com)

Popular in

December

Cheapest in

November

Average price

$319

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.
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Provider most trusted by Cheapflights users for Chicago (CHI)-Ontario flights.
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From Chicago (CHI) to Ontario
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One-way flight from Chicago (CHI) to Ontario
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Highest demand for flights based on searches. 0% potential increase in price ($0 potential increase over avg. RT price).
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Cheapest flight prices on average. 4% potential price decrease ($12 potential savings vs. average RT price).
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Average for round-trip flights in March 2025
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Price to beat on a round-trip flight from Chicago (CHI) to Ontario.
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Price to beat on a one-way flight from Chicago (CHI) to Ontario.
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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 March 28, 2025.

This United Airlines deal was found by Cheapflights users on 3/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/107:55 pmORD - ONT
Nonstop4h 31mUnited Airlines
Sun 10/127:00 amONT - ORD
Nonstop4h 03mUnited Airlines
Deal found 3/26$227
This Frontier deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/185:01 amORD - ONT
1 stop13h 50mFrontier
Sun 4/208:29 amONT - ORD
1 stop10h 48mFrontier
Deal found 3/28$238
This Frontier deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/178:50 pmMDW - ONT
1 stop12h 35mFrontier
Sun 4/208:29 amONT - MDW
1 stop11h 58mFrontier
Deal found 3/27$238
This Alaska Airlines deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/66:00 amORD - ONT
1 stop11h 32mAlaska Airlines
Mon 5/126:24 pmONT - ORD
1 stop9h 41mAlaska Airlines
Deal found 3/27$246
This American Airlines deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/112:48 pmORD - ONT
1 stop10h 45mAmerican Airlines
Tue 7/154:45 pmONT - ORD
1 stop5h 52mAmerican Airlines
Deal found 3/27$247
This Delta deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/217:30 amORD - ONT
1 stop6h 45mDelta
Sun 5/251:10 pmONT - ORD
1 stop6h 30mDelta
Deal found 3/27$257
This Delta deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/211:00 pmMDW - ONT
2 stops11h 29mDelta
Mon 8/2510:59 pmONT - MDW
2 stops11h 31mDelta
Deal found 3/27$267
This Southwest deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/206:55 pmORD - ONT
1 stop6h 05mSouthwest
Thu 5/293:55 pmONT - ORD
1 stop5h 45mSouthwest
Deal found 3/27$283
This Southwest deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/98:25 amMDW - ONT
1 stop7h 45mSouthwest
Tue 5/136:00 amONT - MDW
Nonstop3h 50mSouthwest
Deal found 3/27$322

Cheapflights Fare Finder

Customize your flight search to find flights from Chicago to Ontario 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, Cheapflights users made 2,558,603 searches. Data last updated March 28, 2025.
Use the filters below to find and compare flights from Chicago to Ontario that are best for you.

Fly from

Chicago

Fly to

Ontario

Route

Depart

Return

Price

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Sat 5/24

7:55 pm-10:26 pm

Nonstop4h 31m

Ontario

Sun 6/1

7:00 am-1:03 pm

Nonstop4h 03m

$227

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Fri 4/18

5:01 am-4:51 pm

1 stop13h 50m

Ontario

Sun 4/20

8:29 am-9:17 pm

1 stop10h 48m

$238

ChicagoOntario

MDW - ONT

MDWONT

Chicago Midway

Thu 4/17

8:50 pm-7:25 am

1 stop12h 35m

Ontario

Sun 4/20

8:29 am-10:27 pm

1 stop11h 58m

$238

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Tue 5/6

6:00 am-3:32 pm

1 stop11h 32m

Ontario

Mon 5/12

6:24 pm-6:05 am

1 stop9h 41m

$246

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Tue 7/1

12:48 pm-9:33 pm

1 stop10h 45m

Ontario

Tue 7/15

4:45 pm-12:37 am

1 stop5h 52m

$247

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Wed 5/21

7:30 am-12:15 pm

1 stop6h 45m

Ontario

Sun 5/25

1:10 pm-9:40 pm

1 stop6h 30m

$257

ChicagoOntario

MDW - ONT

MDWONT

Chicago Midway

Thu 8/21

1:00 pm-10:29 pm

2 stops11h 29m

Ontario

Mon 8/25

10:59 pm-12:30 pm

2 stops11h 31m

$267

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Tue 5/20

6:55 pm-11:00 pm

1 stop6h 05m

Ontario

Thu 5/29

3:55 pm-11:40 pm

1 stop5h 45m

$283

ChicagoOntario

MDW - ONT

MDWONT

Chicago Midway

Fri 5/9

8:25 am-2:10 pm

1 stop7h 45m

Ontario

Tue 5/13

6:00 am-11:50 am

Nonstop3h 50m

$322

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Sat 4/12

7:46 pm-7:25 am

1 stop13h 39m

$105

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/27

Showing 1-10 of 21 results
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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 March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*3 stars
CheapOairPrice Accuracy1 starTrust Score*3 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy1 starTrust 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 FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Chicago-Ontario flight deals on Cheapflights vs. FlightHub >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 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 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?

Use this chart to determine the optimal time to book a round-trip flight from Chicago to Ontario. Price data was last updated on March 21, 2025.

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 $326). 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?

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 March 28, 2025.

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?

Use this chart to determine the cheapest time to fly round-trip from Chicago to Ontario. Price data was last updated on March 23, 2025.

Travelers seeking maximum savings on their Chicago to Ontario flight should consider departing on Monday evenings 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

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

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

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 March 28, 2025.
Peruse reviews from past customers who have flown with Southwest, Alaska Airlines 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.
Southwest
8.1
Very good
4,274 reviews

Comfort

8.1

Crew

8.7

Food

7.1

Boarding

8.2

Entertainment

7.6

Overall

8.1

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
Southwest
8.1
Very good
4,274 reviews
Southwest
8.1
Very good
4,274 reviews

Comfort

8.1

Crew

8.7

Food

7.1

Boarding

8.2

Entertainment

7.6

Overall

8.1

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
Alaska Airlines
8.0
Very good
9,798 reviews
Southwest
8.1
Very good
4,274 reviews

Comfort

8.1

Crew

8.7

Food

7.1

Boarding

8.2

Entertainment

7.6

Overall

8.1

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
Delta
8.0
Very good
7,897 reviews
Southwest
8.1
Very good
4,274 reviews

Comfort

8.1

Crew

8.7

Food

7.1

Boarding

8.2

Entertainment

7.6

Overall

8.1

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
Hawaiian Airlines
7.9
Good
2,336 reviews
Southwest
8.1
Very good
4,274 reviews

Comfort

8.1

Crew

8.7

Food

7.1

Boarding

8.2

Entertainment

7.6

Overall

8.1

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.
United Airlines
7.4
Good
8,603 reviews
Southwest
8.1
Very good
4,274 reviews

Comfort

8.1

Crew

8.7

Food

7.1

Boarding

8.2

Entertainment

7.6

Overall

8.1

Reviews

1 / 20
10.0
Excellent

Merlyn,Feb 2025

LAX - SMF

New Terminal is neat, lost of stores and places to catch a bite.

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?

    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 United Airlines is currently your cheapest option to Ontario, with prices starting at $227. Additional round-trip tickets that might be worth considering are offered by Frontier and Alaska Airlines, with the lowest prices starting at $238 and $246, respectively. United Airlines is currently priced 20% 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 Hawaiian Airlines start at $123 one-way.

  • What are the cheapest flights from Chicago to Ontario?

    While on average a flight from Chicago to Ontario is generally $255, 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 $227 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 $326). 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.

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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.
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Top 5 airlines flying from Chicago to Ontario

Discover the top 5 airlines that operate flights from Chicago to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$121Average$199FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$238Average$356FlexibilityNo cancel feeOn-time71%
DeltaCheapest$246Average$450FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$256Average$485FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$256Average$478FlexibilityNo cancel feeOn-time63%
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