ONT - CHI

$108 Find Cheap Flights from Ontario to Chicago

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ontario to Chicago departing on 7/15. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Chicago

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Chicago, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Chicago, as well as popular online travel agencies
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 21% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Everything you should know

Cheapest round-trip
$283
Typical prices: $258-$457
Southwest
Thu 8/6Sat 8/15
ONT - MDW • Non-stop
Cheapest non-stop
$294
Typical prices: $438-$633
United Airlines
Tue 7/21Wed 7/29
ONT - ORD • Non-stop
Advice from real travelers
AI-powered summary based on content written by travel experts. AI can make mistakes.
Southwest free carry-on adds value, while checked bags now cost extra.
United Economy Plus adds up to 6 inches more legroom than standard economy.
Expert advice
Expert advice
Expert advice
Expert advice
Top airlines
Cheapest • from $283 (round-trip)
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
You can fly direct with Southwest and United Airlines. Average duration is 4h 00m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
Top routes
Cheapest • 6% average savings
Most popular
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $245 (round-trip)
Shortest trip • 5h 17m (one-way)
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 4 weeks in advance save around 38% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 32% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Chicago!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from Ontario to Chicago (ONT-CHI)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Ontario to Chicago that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Ontario to Chicago

Thu, Aug 6 - Sat, Aug 15
Southwest Logo
11:55 pm - 5:45 am
ONT
-
MDW
3h 50mnonstop
Southwest Logo
10:05 am - 4:00 pm
MDW
-
ONT
7h 55m
2 stops
$283Southwest
Sun, Aug 2 - Thu, Aug 6
Frontier Logo
8:17 am - 8:32 pm
ONT
-
MDW
10h 15m
1 stop
Frontier Logo
9:27 pm - 8:41 am
MDW
-
ONT
13h 14m
1 stop
$284Frontier
Thu, Aug 6 - Sun, Aug 9
Frontier Logo
11:47 am - 5:37 am
ONT
-
ORD
15h 50m
1 stop
Frontier Logo
5:30 pm - 7:32 am
ORD
-
ONT
16h 02m
1 stop
$284Frontier
Wed, Aug 26 - Thu, Aug 27
Southwest Logo
6:40 am - 5:10 pm
ONT
-
MDW
8h 30m
2 stops
Southwest Logo
8:00 am - 3:05 pm
MDW
-
ONT
9h 05m
2 stops
$285Southwest
Tue, Jul 21 - Wed, Jul 22
Frontier Logo
9:32 am - 12:49 am
ONT
-
ORD
13h 17m
1 stop
Frontier Logo
5:46 pm - 7:32 am
ORD
-
ONT
15h 46m
1 stop
$285Frontier
Fri, Aug 21 - Mon, Aug 24
Frontier Logo
8:17 am - 8:31 pm
ONT
-
MDW
10h 14m
1 stop
Frontier Logo
9:26 pm - 8:36 am
MDW
-
ONT
13h 10m
1 stop
$286Frontier
Sat, Jul 18 - Thu, Jul 23
Frontier Logo
6:00 am - 8:52 pm
ONT
-
ORD
12h 52m
1 stop
Frontier Logo
5:46 pm - 7:32 am
ORD
-
ONT
15h 46m
1 stop
$286Frontier
Wed, Sep 9 - Thu, Sep 17
Delta Logo
12:17 pm - 10:45 pm
ONT
-
MDW
8h 28m
1 stop
Delta Logo
5:11 pm - 10:26 pm
MDW
-
ONT
7h 15m
1 stop
$288Delta
Thu, Aug 27 - Tue, Sep 1
Delta Logo
11:56 am - 11:29 pm
ONT
-
ORD
9h 33m
1 stop
Delta Logo
2:00 pm - 10:45 pm
ORD
-
ONT
10h 45m
2 stops
$293Delta
Tue, Jul 21 - Wed, Jul 29
United Airlines Logo
6:10 am - 12:25 pm
ONT
-
ORD
4h 15mnonstop
United Airlines Logo
8:18 pm - 10:51 pm
ORD
-
ONT
4h 33mnonstop
$294United Airlines
Booking Insights

KAYAK's insights & trends for Ontario to Chicago flights

Get data-powered insights and trends into flights from Ontario to Chicago to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from Ontario to Chicago?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Ontario to Chicago departing in August.

What is the cheapest Ontario to Chicago flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest return flight from Ontario to Chicago costs $297 on the route between Ontario (ONT) and Chicago O'Hare Intl Airport (ORD). Over the past month, this route was, on average, 6% cheaper than other Ontario-Chicago routes. It is also the most popular route.

What’s the cheapest day of the week to fly from Ontario to Chicago?

The average price of all round-trip flights from Ontario to Chicago clicked on KAYAK for each day over the last 12 months.

Your flight ticket price will generally be cheaper if you fly to Chicago on a Wednesday and more expensive on a Sunday. On your return trip to Ontario, you should consider flying back on a Wednesday, and avoid Sundays for better deals.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to Chicago, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Ontario to Chicago is September, where tickets cost $102 (return) on average. On the other hand, the most expensive months are March and May, where the average cost of round-trip tickets is $186 and $186 respectively.

Can I save money by flying with a layover from Ontario to Chicago?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at $440 on average.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Ontario to Chicago, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Ontario to Chicago, you should book around 4 weeks before departure, which saves you about 38% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 9 weeks before departure.

Expert advice

Expert advice for your flight from Ontario to Chicago

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on United Airlines, ORD and MDW

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Blane Bachelor

Blane Bachelor

Expert on Southwest

Blane Bachelor is a journalist and editor specializing in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favorite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history. She will always choose the window seat.

Jennifer Simonson

Jennifer Simonson

Expert on ONT

Jennifer Simonson is driven by her lifelong commitment to exploring the globe. Her insatiable curiosity had led her to immerse herself into diverse locations like Oklahoma City and Pismo. Her hotel recommendations are the result of the myriad hotels she's stayed at across her travels. Along her journey, she cherishes engaging conversations with locals, indulging in the finest ice cream, trying her hand at surfing, and embarking on nature-filled hikes.

Good to know

Low seasonJanuary
Cheapest flight$108
Best time to beat the crowds with an average 21% drop in price.
Most popular time to fly and prices are also 14% lower on average.
Flight from Ontario to Chicago O'Hare Airport

When to book flights from Ontario to Chicago

Are your dates flexible? Find out the best times to travel from Ontario to Chicago based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Ontario to Chicago

  • Which is the best arrival airport if I want to visit the Museum of Science and Industry?

    ORD offers the best linkage to The Museum of Science and Industry, which lies approximately 24.2 miles away. Bus line 6 provides the most convenient connection to this attraction, covering the journey in about 1h 18min. For a quicker connection, take a taxi and get there in under 30min.

  • Is there a prayer room at Chicago Midway International Airport (MDW)?

    Religious souls landing at MDW from ONT and want to thank the Almighty for the safe trip will find a sacred suite where they can retreat quietly and respectfully. You can locate this sanctuary in Concourse C on the mezzanine level, and it’s open 24/7.

  • Are there car rentals from O'Hare International Airport (ORD) to downtown Chicago?

    There’s a wide range of car rental services at ORD, ideal for anyone keen to explore Chicago in a car. Once you land at the airport, locate your car dealer’s desk in the arrival hall. A free shuttle will drop you at the pick-up point at Routes Car & Truck Rentals at 3901 Mannheim Rd, Schiller Park.

  • Does O'Hare International Airport run an art program?

    ORD boasts an extensive exhibition of unique pieces of art and crafts throughout its terminals. Consider killing time in concourses B and C and enjoy the various sculptures, murals, and paintings.

  • What is the cheapest flight from Ontario to Chicago?

    In the last 5 days, the lowest price for a flight from Ontario to Chicago was $108 for a one-way ticket and $283 for a round-trip.

  • Do I need a passport to fly between Ontario and Chicago?

    No, a passport isn't needed to fly from Ontario to Chicago. However, local authorities might ask for an official ID.

  • Which airports will I be using when flying from Ontario to Chicago?

    On your way to Chicago, you’ll fly out from Ontario. You’ll be landing in one of Chicago’s 2 airports: Chicago Midway or Chicago O'Hare Intl.

  • Which airlines offer Wi-Fi service onboard planes from Ontario to Chicago?

    JetBlue, Alaska Airlines, Delta, Hawaiian Airlines, and American Airlines offer inflight Wi-Fi service on the Ontario to Chicago flight route.

  • Which aircraft models fly most regularly from Ontario to Chicago?

    The Boeing 737-900 is the aircraft model that flies most regularly on the Ontario to Chicago flight route.

  • Which airline alliances offer flights from Ontario to Chicago?

    SkyTeam, oneworld, and Star Alliance are the airline alliances operating flights between Ontario and Chicago, with SkyTeam being the most commonly used for this route.

  • On which days can I fly direct from Ontario to Chicago?

    There are nonstop flights from Ontario to Chicago on a daily basis.

  • Which is the best airline for flights from Ontario to Chicago, Southwest or Delta?

    The two airlines most popular with KAYAK users for flights from Ontario to Chicago are Southwest and Delta. With an average price for the route of $486 and an overall rating of 7.9, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $428 and an overall rating of 7.8.

  • How does KAYAK find such low prices on flights from Ontario to Chicago?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ontario to Chicago.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ontario to Chicago?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Chicago from Ontario is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Ontario to Chicago?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Chicago with an airline and back to Ontario with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ontario to Chicago?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Chicago from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Ontario to Chicago

  • Looking for a cheap flight? 25% of our users found flights on this route for $256 or less one-way and $421 or less round-trip.
  • Ontario International Airport (ONT) is a hub of multiple licensed car and shuttle operators providing services to several destinations within and beyond this establishment. Many run counters at the passenger terminals, parking lots, and car rental centers. Still, most of the nearby airport hotels offer courtesy shuttles to and from the airport.
  • Those who intend to leave ONT for Chicago early in the morning will find it helpful if they spend a night in one of the hotels near Ontario International Airport (ONT). Usually, such properties offer complimentary cars to and from the departure terminal, thus enabling you to be there in time for your voyage. La Quinta Inn & Suites by Wyndham Ontario Airport guarantees that stay.
  • If you’re departing from Ontario International Airport (ONT) to Chicago, remember that the establishment has three terminals. If you're using United Airlines, you’ll leave via Terminal 2, while Terminal 4 serves Southwest Airlines. Movement from one terminal to the other is via an Inter-Terminal Shuttle, which runs every 5-10min on the landside.
  • Those flying aboard American Airlines from ONT to Chicago should know that the carrier runs its hub at Chicago O'Hare International Airport (ORD). Passengers arrive at ORD via Terminal 3 and can retreat to the Admirals Club in the same terminal, Airside. Members and registered cardholders enjoy priority access and clearance under the fast lane program. Still, Economy Class travelers can enjoy the suite after paying for the day’s pass.
  • Southwest Airlines allows passengers from Ontario International Airport (ONT) to Chicago to bring their furry friends into the cabin. Usually, these four-legged friends are household animals such as cats, dogs, and birds. The pets must bear their valid medical certificates and remember to lock them in their kernels throughout the trip.

Prefer to fly direct from Ontario to Chicago?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Ontario to Chicago.
Find which airlines fly direct from Ontario Airport to Chicago, which days they fly and book direct flights.

Direct departures

Ontario to Chicago

Monday

Southwest,United Airlines

Southwest,United Airlines

Tuesday

Southwest,United Airlines

Southwest,United Airlines

Wednesday

Southwest,United Airlines

Southwest,United Airlines

Thursday

Southwest,United Airlines

Southwest,United Airlines

Friday

Southwest,United Airlines

Southwest,United Airlines

Saturday

Southwest,United Airlines

Southwest,United Airlines

Sunday

Southwest,United Airlines

Southwest,United Airlines

See more direct flights

Direct returns

Chicago to Ontario

Monday

Southwest,United Airlines

Southwest,United Airlines

Tuesday

Southwest,United Airlines

Southwest,United Airlines

Wednesday

Southwest,United Airlines

Southwest,United Airlines

Thursday

Southwest,United Airlines

Southwest,United Airlines

Friday

Southwest,United Airlines

Southwest,United Airlines

Saturday

Southwest,United Airlines

Southwest,United Airlines

Sunday

Southwest,United Airlines

Southwest,United Airlines

See more direct flights

Reviews of the top 4 airlines serving from Ontario to Chicago

 
See real verified KAYAK customer reviews for airlines flying from Ontario to Chicago. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Ontario to Chicago? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.9
SouthwestOverall score based on 4246 reviews
7.5Entertainment
8.6Crew
7.0Food
8.0Comfort
8.1Boarding
Airline reviews

Flight was delayed, full flight and I had to change gates. Southwest flights are always late later in the day.

4.0 OkaySteven, Jun 2026
ONT - LAS
Read more Southwest reviews

Flight was delayed, full flight and I had to change gates. Southwest flights are always late later in the day.

Flight was delayed over 3 hours. Planes were dirty. Staff indifferent. And they serve vegan pretzels as snacks.

The flight was smooth. The Southwest experience has degraded overall, but this one was okay.

The checking experience in Orlando was terrible, almost missed the flight. Too many travelers and Southwest completely understaffed.

no service at all due to turbulence. they should've at least given us snacks, there were only 10 people on the entire flight.

For the first time in a long time, the Wi-Fi actually worked the entire flight! The flight crew was amazing as usual.

Great flight. I didn't get a drink because I was asleep whole on the flight.

Flight was ok. Boarding wasn’t fun. Flights were delayed by 12 minutes on each leg.

Wifi didn’t work, no service, seats are hard as rocks

I liked receiving attention from aged and well experienced flight attendants. I disliked the non-gluten-free snack but I brought my own so I was OK.

It was as good as it could be. Flying is not a pleasant experience these days.

There was an unruly family behind us that made the short flight miserable!!! The cabin crew did nothing to contain it.

Flight delay was frustrating, also you cannot checkin online without delta app, web browser check-in throw errors

Got on the plane and sat there for an hour before departure.

Cramped seating for me. Luckily it wasn’t a long flight

It was a great flight and the stewards and stewardess were all kind and accommodating!! The seats were comfortable and entertainment screen excellent!

737-800 in first class was pretty dumpy. Seat had an uncomfortable angle, storage under the seat was blocked so even my very modest backpack didn't fit, power outlet was flaky. Weird tiny seat pockets that couldn't hold a gallon ziploc bag, emesis bag missing, etc. etc. No in-flight service due to turbulence. Crew was excellent, boarding was smooth despite a full flight.

The flight was overbooked and the staff at the gate started calling for volunteers to drop out and offering incentives. That delayed the flight

There was no wifi even after my husband paid for wifi it wasn’t working. The plane looked and felt old.

Update the cabin with tv screens or at least music sources.

Crew was great (professional, attentive, prompt). Snacks for 4 hrs flight is deplorable.

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

While the staff was pleasant and helpful, the following observations are for your awareness. There was some delay on the tarmac on take off and landing. The paid lunch/food offerings were limited. Entertainment was only available on WiFi at a cost.

The first flight was better in terms of the aircraft.

As usual, United scheduling is completely misleading. A 54-minute layover at O’Hare is too short to make a lot of connections, especially since the flight landed “on time” but had to wait on the taxiway 15 minutes for a gate to open up. Then it takes another 10 minutes to exit the plane before one can run to another concourse to catch a connecting flight.

when you can say you don't remember being at any point upset during a flight, the airline is winning .

I had a great flight. Everything went smoothly and the flight arrived early.

United WiFi is consistently unusable (it can take 10 mins to load a single web page). If you need Wifi to do work, be prepared to lose half a day of productivity.

The Palm Springs to Chicago O’Hare was on Time and Palm Springs airport is easier navigate. As our connection was only an approximately 50 minutes, we asked staff for insights for the Chicago airport in terms of transferring into the other terminal from which our flight left, and they were unhelpful. However, the United App was very helpful in terms of notifications and even providing directions. The Chicago to Detroit flight was significantly delayed which we all know does happen. However, there were very few updates or notifications as to why this was happening when we would actually arrive. It took nearly 30 minutes for bags to make it to baggage claim. We arrived nearly 1 hour late on a 40 minute flight.

Wifi did not work. Cut off on and off every 10 min

Flight was scheduled at 9:40pm. Got delayed to 10 am, the next day. crazy

The takeoff was the smoothest I've ever experienced on any airline and this is the first time I've flown on frontier so this was an extremely pleasant surprise!

A lady asked to stop the flight after the tunnel pulled away and we began to depart a flight that was already hours late. The attendance respectfully stopped the the plane and had the tunnel return. After the tunnel returned the passenger claimed to have changed her mind . The tunnel was then put in reverse and the passenger remained on the plane .. They should have sent the sick passenger off the plane like initially replaced. They existed a couple off the plane prior to that situation.. So.. all and all.. it was a long and flight.. .

We understand and comply with Frontier’s bag sizes. We’ve had some problems in past while having to await other passengers who do not understand the baggage restrictions or have not prepaid and that is usually our biggest concern (others delaying us) with flying Frontier. Flying OUT of ONT, however, has always been a great experience. I’ve also noted even on delayed Frontier flights very knowledgeable pilots who manage expectations well.

Long lines, rude staff, everything that's offered you have to pay for.

The last time I flew Frontier was in the 1960s when it was a “real” airline. We flew this time because of the price & schedule. As the saying goes, you get what you pay for.

I appreciated the upgrade to free cary-on bag and seat selection at no charge

Flight was delayed on the runway for 40 minutes the crew did not even offer even water to passengers to compensate for the flight delayed. The flight was delayed due to aircraft mechanical issues. Worst customer service ever

This isna terribly run airlines. If you're one minute late, they will deny your ticket. Don't waste your time or money

Flight was delayed for more than 3 hours, crew at ONT airport was rude, and when we got to DFW the airplane had an issue landing, we had to be taxied to the terminal, and the luggage was hold until the next day.

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

Information on your arrival and departure airports