ONT - CHI

$79 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 4/21. 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
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Everything you should know

Cheapest round-trip
$258
Typical prices: $518-$313
Frontier
Sun 4/19Mon 4/27
ONT - ORD • 1 stop
Cheapest non-stop
$263
Typical prices: $465-$426
United Airlines
Tue 4/21Sat 4/25
ONT - ORD • Non-stop
Advice from real travelers
AI-powered summary based on content written by travel experts. AI can make mistakes.
United's Economy Plus offers extra legroom on flights.
MDW's Orange Line provides a quick ride to downtown.
Expert advice
Expert advice
Expert advice
Expert advice
Top airlines
Cheapest • from $261 (round-trip)
Best reviews • 8.0 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 3h 57m
Direct flights
Direct flights
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+1
Direct flights
Direct flights
+1
Top routes
Cheapest
Most popular
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $255 (round-trip)
Shortest trip • 5h 15m (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 • 20% price drop
Most popular
Good to know
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+1
+1
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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

Sun, Apr 19 - Mon, Apr 27
Multiple Airlines Logo
12:59 am - 9:50 am
ONT
-
ORD
6h 51m
1 stop
Multiple Airlines Logo
11:28 am - 11:43 pm
ORD
-
ONT
14h 15m
2 stops
$258Multiple Airlines
Sat, Apr 11 - Wed, Apr 15
Multiple Airlines Logo
6:20 am - 12:38 am
ONT
-
ORD
16h 18m
1 stop
Multiple Airlines Logo
6:16 pm - 4:38 pm
ORD
-
ONT
24h 22m
1 stop
$259Multiple Airlines
Sat, Apr 11 - Wed, Apr 15
Multiple Airlines Logo
6:20 am - 11:59 pm
ONT
-
ORD
15h 39m
2 stops
Multiple Airlines Logo
6:16 pm - 4:38 pm
ORD
-
ONT
24h 22m
1 stop
$260Multiple Airlines
Thu, Apr 23 - Tue, Apr 28
Delta Logo
12:49 pm - 10:28 pm
ONT
-
MDW
7h 39m
1 stop
Delta Logo
6:00 am - 11:36 am
MDW
-
ONT
7h 36m
1 stop
$261Delta
Wed, May 20 - Wed, May 27
Delta Logo
6:45 am - 4:49 pm
ONT
-
ORD
8h 04m
1 stop
Delta Logo
7:45 pm - 11:34 pm
ORD
-
ONT
5h 49m
1 stop
$261Delta
Thu, Apr 16 - Sun, Apr 19
Frontier Logo
11:47 am - 6:08 am
ONT
-
ORD
16h 21m
1 stop
Frontier Logo
8:58 pm - 10:14 am
ORD
-
ONT
15h 16m
1 stop
$262Frontier
Sun, May 17 - Sun, May 24
Frontier Logo
8:06 pm - 3:43 pm
ONT
-
ORD
17h 37m
1 stop
Frontier Logo
9:42 pm - 10:05 am
ORD
-
ONT
14h 23m
1 stop
$263Frontier
Sun, Apr 26 - Thu, Apr 30
Multiple Airlines Logo
8:21 am - 10:23 am
ONT
-
ORD
48h 02m
2 stops
Multiple Airlines Logo
8:58 pm - 8:04 am
ORD
-
ONT
13h 06m
1 stop
$265Multiple Airlines
Mon, Apr 27 - Mon, May 4
Southwest Logo
9:55 pm - 7:35 am
ONT
-
MDW
7h 40m
1 stop
Southwest Logo
4:35 pm - 11:05 pm
MDW
-
ONT
8h 30m
2 stops
$266Southwest
Tue, Apr 21 - Sat, Apr 25
Southwest Logo
6:55 am - 4:35 pm
ONT
-
MDW
7h 40m
2 stops
Southwest Logo
10:30 am - 5:50 pm
MDW
-
ONT
9h 20m
2 stops
$271Southwest
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 April.

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 $296 on the route between Ontario (ONT) and Chicago Midway Airport (MDW). This 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 Thursday and more expensive on a Sunday. On your return trip to Ontario, you should consider flying back on a Tuesday, and avoid Saturdays 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 January, where tickets cost $307 (return) on average. On the other hand, the most expensive months are December and March, where the average cost of round-trip tickets is $543 and $458 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 $436 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 25 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$79
Best time to beat the crowds with an average 20% drop in price.
Most popular time to fly and prices are also 5% 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

  • What is the cheapest flight from Ontario to Chicago?

    In the last 3 days, the lowest price for a flight from Ontario to Chicago was $79 for a one-way ticket and $258 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?

    Delta, Alaska Airlines, JetBlue, 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 MAX 8 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 $476 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $397 and an overall rating of 7.9.

  • 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 $244 or less one-way and $393 or less round-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 5 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.
8.0
SouthwestOverall score based on 4332 reviews
8.0Comfort
8.1Boarding
7.0Food
8.6Crew
7.5Entertainment
Airline reviews

It was good from LAX to Phoenix, But the connection in Phoenix to Tulsa was not that great. The staff on both flights were great. The choice of free entertainment was ok nothing to brag about. The 45 min delay because of some electrical issue wasn't great from Phoenix to Tulsa. We sat there with hardly any air, The seat I had was between windows so the side of the plane pushed in on you. My being a bigger man it then made the seating area uncomfortable. The seats on the plane had no power to connect to recharge your phone or anything. I would recommend that they should look into a slot or clamp to hold your phone to enjoy while watching the entertainment choices hands-free. Also make it possible to raise the inner seat by the window be able to raise the arm rest up to make more room for larger people to set more comfortably. I would also say other then that stop price gouging the airfare or nickel and diming everything. Not fair for people having to fly for emergencies and be paying for higher prices due to the season or holidays. Your making your money either way and the cost of flying is still going to be the same regardless if there's 100 people or 200 people.

10.0 ExcellentAnthony & Kathy, Mar 2026
LAX - PHX
Read more Southwest reviews

It was good from LAX to Phoenix, But the connection in Phoenix to Tulsa was not that great. The staff on both flights were great. The choice of free entertainment was ok nothing to brag about. The 45 min delay because of some electrical issue wasn't great from Phoenix to Tulsa. We sat there with hardly any air, The seat I had was between windows so the side of the plane pushed in on you. My being a bigger man it then made the seating area uncomfortable. The seats on the plane had no power to connect to recharge your phone or anything. I would recommend that they should look into a slot or clamp to hold your phone to enjoy while watching the entertainment choices hands-free. Also make it possible to raise the inner seat by the window be able to raise the arm rest up to make more room for larger people to set more comfortably. I would also say other then that stop price gouging the airfare or nickel and diming everything. Not fair for people having to fly for emergencies and be paying for higher prices due to the season or holidays. Your making your money either way and the cost of flying is still going to be the same regardless if there's 100 people or 200 people.

Love them will get a Southwest card to track my points and keep flying with them. My family and I were pleased with the services.

Southwest was greaat! The most expensive but the least upsetting for those we were flying to see.

Boarding was easy. The seats are small and fairly uncomfortable

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

Good but I prefer choose your own seat. With the new assigned seats they should board from the back I see no advantage to this new boarding. Just like every other airline

WiFi was not working and didn’t have a beverage service

Flight boarded late after announcing on time boarding. Flight arrived only a little late despite late departure. Had trouble connecting to WiFi

The Southwest experience has definitely taken a dive from its early days. You can no longer deferentiate from other airlines. Air travel is too expensive. Southwest is no longer budget friendly. They have lost me as a loyal customer.

The charges were ridiculous for an hour flight and the turbulence was very scary.

Long flight but comfortable and not freezing as I have experienced on Hawaiian flights to the islands. They gave us blankets just in case. Nice touch.

I took seat 15A in anticipation of window seat, there is no window.

Flight late, the waited for a long time for “personal” to arrive at gate to dock the plane in Rochester. So annoying. This flight was expected, why aren’t personel available for the jet bridge?

My recent experience was excellent on Delta! I flew with Delta Comfort and I was really comfortable in my seat. I enjoyed the in-flight service. The flight attendants were so friendly and hospitable. I love the snack on the flight as well. This was my first time flying on Delta and I will definitely consider flying with them again.

My flight was canceled on Sunday. Rebooking took three hours. Had to pay for accommodations another night. New flight was delayed for 5 hours, all that was sent was a 12 dollar food voucher, which doesn’t tell you how to use it. Then when we landed we had to sit on the plane for an hour before we could get off.

I was in first class and literally the men behind me were so aggressively loud I moved myself to economy. This has become so common on Delta - people using audio without headphones, and men on 12am / late night flights drinking and yelling to talk to each other which prevents anyone around them from resting. Pretty crazy to have to move from first to economy (poorer service, less comfort...). Wild wild. Looking into other airlines.

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

Flight was delayed by 3-hours and their fix was… complimentary pretzels.

The crew, and fellow passengers, were super gracious and kind. There seemed to be plenty of bin space even though the plane was full. It’s nice to get a glass of wine with dinner in Premiere seating, and there was a lot of food.

Everything I mentioned earlier - the airbus was more comfortable indeed and the experience was further enhanced.

3 hour delay…. Nearly 2 hours sitting on tarmac. Do better, United. Or at least have the sense to not say “we hope you enjoyed your flight with us” upon disembarking.

Flights were on time. Free Wifi on plane. Everything was well organized.

Economy plus was so cramped I could not use my laptop. It was beyond bad.

Wonderful. Quick boarding. Early departure and we arrived 30 minutes early at our destination. Unfortunately, when you arrive early, there is still a departing aircraft at our gate. We had to park for 30 minutes until the gate was clear. So our early arrival was not really early at the gate. Otherwise it was a quick and smooth flight. Appreciated the efficiency.

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

United Airlines is my preferred airlines and I am thankful for Gary who also help support me on the phone to switch my flight literally last min.

Seated dude next to me even though lots of empty rows. But main thing was we sat on the tarmac after landing for 30 minutes because of, in the words of the dude who sat next to me, “operational incompetence”. We got changing directions about where to pick up gate checked bags. Pilot and flight attendant were awesome though.

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.

Perfect flight. Smooth flight. Arrived 20 minutes early at destination. Excellent service.

The flights were on time which was great give. It was holiday travel season and there’d been some weather issues. The only complaint and this is every time with United is the terrible seat design. The head rest is not built for comfort and having my neck bent forward for a cross country trip reminded me while I try not to take United flights as a rule.

The staff are very, very professional. It's what flying should feel like.

Flight was delayed half hour before boarding, but when I checked flight aware the plane that would Pick us up had a delay of more than an hour. AA should let us know in advance to avoid waiting several hours in the airport

Delays with no explanation. It could have been handled better.

Jill was the flight attendant in first class she was fabulous!! Best flight attendant I have had in years.!! And I fly every other week. Other can learn from her!!

As a first class customer, there was no power the entire flight which limited my ability to work. I find this unacceptable. The first 11 rows on the left side of the plan were out. I was only offered the option to charge my phone which was not the issue because my laptop was out of power. I asked if there was anything that can be done for me, and the answer was, "no". I was not offered any type of compensation for this AA problem which caused me unnecessary stress due to inability to address business issues on an already challenging travel day. Flight attendants tried to reset the power once but that was the extent of their support. Very disappointing for the lack of expected services on a flight. Please contact me with customer focused response to this complaint.

There was no inflight service. Once we landed we were delayed to find a gate for an hour and a half which was 1/2 the total time in the air.

The chicken wrap was tiny ($13 for what looked like a 1/3 of a normal wrap?) and disgusting.

It was good experience this time. The flight was on time.

There was a delay with the plan which cause the flight to leave later and once arrived in Chicago there was another delay and some passengers missed their connecting flights

The gate agent had a really bad attitude and refused to help me get on the standby list. She just handed me a card and said I needed to call a number. I asked her to help with the AA app on my phone and she just shrugged and said she didnt know. After a few phone calls, I eventually just went to a different gate agent on the other side of the terminal and got the help I needed.

Remind customers of the need to have passport or new ID for boarding.

The flight never took off and we spent 7 hours at the airport

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

It was ok. It was expensive to check 2 bags ($75.00 per bag), and then it took a long time to wait for shuttle to take us from one terminal to the terminal where the plane was taking off at LAX. And all of this for a flight where we had to pay for any food or drink that was not water.

This company socks. It's fraud. They canceled our flight yesterday, and today we were late because of a really long line at the check in bag. At the rebook station, there was ton of people. The workers were all rude. I am gonna make a report to FTC.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

The single worst check in experience I could imagine. I’ll never do any business with Frontier or any affiliated company

Too many extra fees, uncomfortable, little leg room. Will not recommend this airline.

This airline sucks. They offer low rates then charge you for everything, the app does not work well, the seats are the most uncomfortable. Maintenance issues on the flight, and you still have to sit through their credit card commercials. People are nice enough but does not make up for overall poor experience.

Severe turbulence. Captain never came on to reassure passengers after things settled down.

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

Information on your arrival and departure airports