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Cheap Flights from Ontario International to Chicago

Compare Ontario International to Chicago flight deals

Find the cheapest month or even day of the year to fly to Chicago

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Flight deals from Ontario International Airport to Chicago

Looking for a cheap last-minute deal or the best return flight from Ontario International Airport to Chicago? If you want to travel next month, return fares start from R 2,714. Find the lowest prices on one-way and return tickets right here.
Chicago.R 1,277 per passenger.Departing Wed, 10 Jun.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Ontario International on Wed, 10 Jun, arriving in Chicago O'Hare International.Price includes taxes and charges.From R 1,277, select.
Chicago.R 1,357 per passenger.Departing Wed, 22 Apr.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Ontario International on Wed, 22 Apr, arriving in Chicago O'Hare International.Price includes taxes and charges.From R 1,357, select.
Chicago.R 1,463 per passenger.Departing Fri, 8 May.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Ontario International on Fri, 8 May, arriving in Chicago O'Hare International.Price includes taxes and charges.From R 1,463, select.
Chicago.R 2,052 per passenger.Departing Wed, 6 May.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Ontario International on Wed, 6 May, arriving in Chicago Midway.Price includes taxes and charges.From R 2,052, select.
Chicago.R 2,058 per passenger.Departing Mon, 1 Jun.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Ontario International on Mon, 1 Jun, arriving in Chicago Midway.Price includes taxes and charges.From R 2,058, select.
Chicago.R 2,058 per passenger.Departing Mon, 20 Apr.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Ontario International on Mon, 20 Apr, arriving in Chicago Midway.Price includes taxes and charges.From R 2,058, select.
Chicago.R 2,146 per passenger.Departing Thu, 23 Jul.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Ontario International on Thu, 23 Jul, arriving in Chicago O'Hare International.Price includes taxes and charges.From R 2,146, select.
Chicago.R 3,239 per passenger.Departing Sat, 15 Aug.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Ontario International on Sat, 15 Aug, arriving in Chicago Midway.Price includes taxes and charges.From R 3,239, select.
Chicago.R 3,760 per passenger.Departing Tue, 31 Mar.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Ontario International on Tue, 31 Mar, arriving in Chicago O'Hare International.Price includes taxes and charges.From R 3,760, select.
Chicago.R 4,518 per passenger.Departing Wed, 9 Sep.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Ontario International on Wed, 9 Sep, arriving in Chicago Midway.Price includes taxes and charges.From R 4,518, select.
Chicago.R 4,518 per passenger.Departing Fri, 7 Aug.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Ontario International on Fri, 7 Aug, arriving in Chicago Midway.Price includes taxes and charges.From R 4,518, select.
Chicago.R 4,518 per passenger.Departing Mon, 6 Jul.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Ontario International on Mon, 6 Jul, arriving in Chicago Midway.Price includes taxes and charges.From R 4,518, select.
Chicago.R 4,523 per passenger.Departing Fri, 2 Oct.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Ontario International on Fri, 2 Oct, arriving in Chicago Midway.Price includes taxes and charges.From R 4,523, select.
Chicago.R 11,013 per passenger.Departing Mon, 30 Mar.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Ontario International on Mon, 30 Mar, arriving in Chicago Midway.Price includes taxes and charges.From R 11,013, select.

Find the cheapest month to fly from Ontario International to Chicago

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Ontario International to Chicago flights are currently cheapest in June.
Mar
from R 3,760
Apr
from R 1,357
May
from R 1,463
Jun
from R 1,277
Jul
from R 2,146
Aug
from R 3,239
Sep
from R 4,518
Oct
from R 4,523
Nov
Find prices
Dec
Find prices
Jan
Find prices
Feb
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Direct flights from Ontario International to Chicago

Alternative Ontario International to Chicago routes

Looking for the cheapest, fastest or easiest route from Ontario International to Chicago? You could fly into the following airports instead.

Chicago Midway

14km from central Chicago
Closest
from R 2,052
Search flights

Chicago O'Hare International

25km from central Chicago
Cheapest
from R 1,277
Search flights

Chicago Dupage County

51km from central Chicago
Search flights

Chicago Rockford

126km from central Chicago
from R 2,763
Search flights

Ontario to Chicago: Flight information

The things to know before you go.
Cheapest flight foundR 1,277
Cheapest month to flyJune
Average flight time3 hrs, 57 mins
Most popular airlineUnited
Average flights per week18

Finding cheap flights from Ontario International to Chicago: Frequently asked questions

There are 4 airports in Chicago: Chicago Midway, Chicago O'Hare International, Chicago Dupage County, and Chicago Rockford.
The best price we found for a return flight from Ontario International to Chicago is R 2,714. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
3 hours and 57 minutes is the average flight time from Ontario International to Chicago.
United and Southwest Airlines fly direct from Ontario International to Chicago.
As of March 2026, there are 18 flights per week flying from Ontario International to Chicago.
The cheapest month to fly from Ontario International to Chicago is usually April.
If you're flying from Ontario International Airport, the cheapest airport near Chicago is Chicago O'Hare International – which is 25.4 km away from the centre of Chicago. We've found flights into this airport from R 2,714.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Ontario International Airport to Chicago on Tuesday, 21 April 2026.
Yes – the average flight time is 3 hours and 57 minutes.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Chicago but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.
We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to Chicago is around 40 days in advance, so don’t leave your flight to the last minute.
In March, the average temperature is usually around 3°C. July is typically the warmest month in Chicago, when it usually averages around 26°C. You can expect the least rain in January. The coldest month is January, with temperatures averaging -8°C. The rainiest month is August.
Currently, Frontier Airlines and United offer the cheapest flight tickets to Chicago.

Flying from Ontario International Airport (ONT) to Chicago: what you need to know

  • The average duration of a direct flight from Ontario International Airport to Chicago is 4 hours 30 minutes.

  • The timezone in Chicago is UTC-5. The city is two hours ahead of Ontario, where Ontario International Airport is located.

  • With six weekly departures between the two airports, Ontario International Airport (ONT) to O'Hare International Airport (ORD) is the most popular route. Catch United Airlines's 07:00 flight to get your trip from ONT to ORD underway.

  • For a stress-free journey, turn up at the airport two hours ahead of international flights and one hour before domestic departures. This will give you enough time to board your ONT to Chicago flight.

  • Delays at check-in and security are likely if you're jetting off during high season, so allow a little extra breathing room. A good rule of thumb for peak times? Arrive up to four hours early for international flights and at least two hours for domestic departures.

  • You can book a direct Ontario International Airport to Chicago ticket. Start your trip at ONT and touch down at O'Hare International Airport (ORD).

  • Book your ticket with United Airlines. This popular carrier operates direct flights from Ontario International Airport to Chicago.

  • Travelling from central Ontario to ONT takes about 1 hour 30 minutes by public transport. If you ride-share, drive or grab a cab, you'll cover the 5 kilometres in 10 minutes or so, depending on traffic conditions.

  • Searching for a hotel near ONT? If you're catching an early flight from Ontario International Airport to Chicago, these accommodation options will put you moments from check-in:

  • 83.6% of flights departing from Ontario International Airport land at their destination as planned. Given its strong on-time performance, delays are unlikely when setting off from ONT.

  • You'll find ONT at 2900 E. Airport Drive.

How to find the cheapest flights from Ontario International Airport (ONT) to Chicago

  • R 1,277 is currently the lowest price for a one-way Ontario International Airport to Chicago flight. Return flight tickets start at R 2,714. These fares can change depending on availability.

  • Get cheap flights from ONT to Chicago by booking two months ahead. Based on our research, that's the sweet spot for picking up a bargain.

  • June is the best month for nabbing an amazing deal on Ontario International Airport to Chicago tickets. If you'd like to travel during a different time of year, the 'Whole month' tool will show you the lowest prices for each month.

  • Stay on top of deals for cheap flights from ONT to Chicago by creating a Price Alert. You'll get an email or notification on the app when a lower fare becomes available.

  • Snag an affordable flight from Ontario International Airport to Chicago with the help of our filters. Choose your ideal duration, number of stops and airlines, then sort the results by 'Cheapest' to see the best deals.

Airports in Chicago

O'Hare International Airport (ORD)

  • O'Hare International Airport (ORD) is around 40 kilometres from the centre of Chicago. If you're getting a cab or a ride-share, the drive takes roughly 35 minutes.

  • It'll take around 55 minutes if you're travelling on public transport.

  • The last thing you need is a long journey to your hotel if you're arriving on a late flight from Ontario International Airport to Chicago. Stay at one of these accommodation options near ORD instead:

  • Get your adventure underway by picking up an O'Hare International Airport rental car. Grab your wheels from Routes Car Rentals, Dollar or Budget and explore beyond Chicago's main sights.

  • Booking your ride from O'Hare International Airport around four weeks before your flight from ONT to Chicago can help you lock in the best possible rate.

  • The street address for ORD is 10000 West O'Hare.

Chicago Midway International Airport (MDW)

  • After your flight from Ontario International Airport to Chicago has hit the tarmac, you can get to the city centre in around 20 minutes by car. Central Chicago is roughly 19 kilometres from Chicago Midway International Airport (MDW).

  • You can expect the trip to take about 45 minutes on public transport.

  • You'll find some comfortable places to park your luggage (and yourself) near MDW. Tuck yourself in and get cosy after your ONT to Chicago flight at any of these well-located options:

  • Dollar, Hertz and Budget make picking up a Chicago Midway International Airport rental car quick and easy. These suppliers are located in or around the terminal and will have you on your way in a heartbeat.

  • Lock in the lowest price by reserving your ride from MDW four weeks ahead of time. You'll also have access to a wider range of vehicles.

  • Chicago Midway International Airport is located at 5700 South Cicero.

Chicago Rockford International Airport (RFD)

  • Make your way to the city centre after your flight from Ontario International Airport to Chicago has arrived. Central Chicago is around 137 kilometres from Chicago Rockford International Airport (RFD) and takes roughly 1 hour 25 minutes to get to by car.

  • The journey takes about 4 hours 15 minutes when travelling by public transport.

  • Enjoy an unhurried start to your trip by choosing a hotel near RFD after your ONT to Chicago flight. Take a load off after a long travel day or simply take a moment to find your footing in a new city at:

  • Start your journey without stressing about how to get to your destination with a Chicago Rockford International Airport rental car. You can book your wheels with trusted companies here like Budget, Alamo and National.

  • If you're hoping for a particular type of vehicle, booking early increases your chances of snagging what you want. Secure your ride from RFD a couple of weeks ahead of your flight from Ontario International Airport to Chicago.

  • The street address for Chicago Rockford International Airport is 2 Airport Cir.

Best time to go to Chicago

  • Carefully consider your trip dates before securing your flight from Ontario International Airport to Chicago. The city comes alive during high season, but rates are usually higher and major attractions can be busy. Visit Chicago in low season if you like a more relaxed vibe.

  • Before locking in your Ontario International Airport to Chicago flight ticket, think about what kind of weather you prefer. July is the warmest month in Chicago, with temperatures ranging from 15ºC (59ºF) to 29ºC (84ºF).

  • January sees average temperatures of between -12ºC (10ºF) and 3ºC (37ºF). Search for a cheap ticket from ONT to Chicago around that time if you want to travel when it's cooler.

More about Chicago

Explore more of United States

  • Columbus is just one of the many places in United States waiting to be explored once you've seen the sights of Chicago. Around 451 kilometres away to the south-east, popular attractions include Franklin Park Conservatory and Botanical Gardens, Ohio Statehouse and German Village.

  • If you want to check out another corner of United States, consider Indianapolis, about 257 kilometres south-east of Chicago. The Children's Museum of Indianapolis, Indianapolis Museum of Art and Indianapolis Zoo are highlights.

Plan the rest of your trip from Ontario to Chicago

Prices shown on this page are estimated lowest prices only. Found in the last 45 days.