CHI - ONT

$95 Find Cheap Flights from Chicago to Ontario

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Chicago to Ontario departing on 4/8. 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 Ontario

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

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Everything you should know

Cheapest round-trip
$312
Overall average: $246
Frontier
Thu 4/16Mon 4/20
ORD - ONT • 1 stop
Cheapest non-stop
$317
Southwest
Tue 4/7Wed 4/15
MDW - ONT • 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 benefits.
ONT provides budget-friendly public transport options.
Expert advice
Expert advice
Expert advice
Expert advice
Top airlines
Cheapest • from $315 (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 4h 21m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
Top routes
Cheapest • 3% average savings
Most popular
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $215 (round-trip)
Shortest trip • 5h 45m (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 27% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 42% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Ontario!
Flight Deals
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Flight Deals

Cheap Flights from Chicago to Ontario (CHI-ONT)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Chicago to Ontario 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 Chicago to Ontario

Thu, Apr 16 - Mon, Apr 20
Multiple Airlines Logo
10:55 am - 7:31 am
ORD
-
ONT
22h 36m
1 stop
Multiple Airlines Logo
8:59 pm - 10:23 am
ONT
-
ORD
35h 24m
2 stops
$312Multiple Airlines
Wed, May 20 - Thu, May 21
Frontier Logo
12:40 pm - 7:11 pm
ORD
-
ONT
8h 31m
1 stop
Frontier Logo
6:00 am - 8:37 pm
ONT
-
ORD
12h 37m
1 stop
$315Frontier
Thu, Apr 16 - Fri, Apr 24
Frontier Logo
6:09 pm - 11:55 pm
ORD
-
ONT
7h 46m
1 stop
Frontier Logo
9:59 pm - 6:08 am
ONT
-
ORD
6h 09m
1 stop
$316Frontier
Tue, Apr 7 - Wed, Apr 15
Southwest Logo
11:00 am - 1:15 pm
MDW
-
ONT
4h 15mnonstop
Southwest Logo
11:55 pm - 5:40 am
ONT
-
MDW
3h 45mnonstop
$317Southwest
Tue, Apr 7 - Tue, May 12
Delta Logo
7:10 pm - 11:51 pm
ORD
-
ONT
6h 41m
1 stop
Delta Logo
1:29 pm - 9:50 pm
ONT
-
ORD
6h 21m
1 stop
$317Delta
Tue, Apr 7 - Mon, Apr 13
Frontier Logo
1:39 pm - 4:23 pm
ORD
-
ONT
28h 44m
1 stop
Frontier Logo
11:10 am - 6:20 am
ONT
-
ORD
17h 10m
1 stop
$318Frontier
Tue, Apr 7 - Thu, Apr 9
Frontier Logo
5:15 pm - 4:23 pm
ORD
-
ONT
25h 08m
1 stop
Frontier Logo
10:27 pm - 12:58 am
ONT
-
ORD
24h 31m
2 stops
$320Frontier
Wed, Apr 8 - Sat, Apr 11
Southwest Logo
4:00 pm - 10:10 pm
MDW
-
ONT
8h 10m
2 stops
Southwest Logo
11:55 pm - 5:40 am
ONT
-
MDW
3h 45mnonstop
$322Southwest
Wed, Jun 3 - Tue, Jun 9
Delta Logo
5:41 pm - 11:34 pm
ORD
-
ONT
7h 53m
2 stops
Delta Logo
2:00 pm - 11:47 pm
ONT
-
ORD
7h 47m
1 stop
$322Delta
Wed, Apr 15 - Fri, Apr 17
Multiple Airlines Logo
3:27 pm - 8:24 am
ORD
-
ONT
18h 57m
2 stops
Multiple Airlines Logo
8:59 pm - 5:25 am
ONT
-
ORD
6h 26m
1 stop
$323Multiple Airlines
Booking Insights

KAYAK's insights & trends for Chicago to Ontario flights

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

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

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

What is the cheapest Chicago to Ontario flight route?

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

The cheapest return flight from Chicago to Ontario costs $323 on the route between Chicago O'Hare Intl Airport (ORD) and Ontario (ONT). Over the past month, this route was, on average, 3% cheaper than other Chicago-Ontario routes. The most popular route is between Chicago Midway Airport (MDW) and Ontario (ONT).

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

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

For Chicago to Ontario, Tuesday is the cheapest day to fly on average and Saturday is the most expensive. Flying from Ontario back to Chicago, the best deals are generally found on Thursday, with Sunday being the most expensive.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Chicago to Ontario, 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 Chicago to Ontario is October, where tickets cost $236 (return) on average. On the other hand, the most expensive months are January and November, where the average cost of round-trip tickets is $554 and $543 respectively.

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

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 $434 on average.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Chicago to Ontario, 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 Chicago to Ontario, you should book around 4 weeks before departure, which saves you about 27% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 26 weeks before departure.

Expert advice

Expert advice for your flight from Chicago to Ontario

 
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
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.

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.

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$95
Best time to beat the crowds but there is an average 35% increase in price.
Most popular time to fly with an average 30% increase in price.
Flight from Chicago O'Hare Airport to Ontario

When to book flights from Chicago to Ontario

Are your dates flexible? Find out the best times to travel from Chicago to Ontario 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 Chicago to Ontario

  • What is the cheapest flight from Chicago to Ontario?

    In the last 3 days, the lowest price for a flight from Chicago to Ontario was $95 for a one-way ticket and $312 for a round-trip.

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

    Even though you are not required to have a passport, keep in mind that an official ID is needed to board the airplane.

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

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

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

    Only American Airlines offers inflight Wi-Fi service on the Chicago to Ontario flight route.

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

    The Boeing 737 MAX 8 is the aircraft model that flies most regularly on the Chicago to Ontario flight route.

  • Which airline alliances offer flights from Chicago to Ontario?

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

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

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

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

    The two airlines most popular with KAYAK users for flights from Chicago to Ontario are Southwest and United Airlines. With an average price for the route of $513 and an overall rating of 8.0, Southwest is the most popular choice. United Airlines is also a great choice for the route, with an average price of $377 and an overall rating of 7.4.

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

    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 Chicago to Ontario.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario from Chicago 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 Chicago to Ontario?

    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 Ontario with an airline and back to Chicago with another airline.

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

    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 Ontario from Chicago 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 Chicago to Ontario

  • Looking for a cheap flight? 25% of our users found flights on this route for $200 or less one-way and $464 or less round-trip.

Prefer to fly direct from Chicago to Ontario?

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

Direct departures

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

Direct returns

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

Reviews of the top 4 airlines serving from Chicago to Ontario

 
See real verified KAYAK customer reviews for airlines flying from Chicago to Ontario. 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 Chicago to Ontario? 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 4319 reviews
8.0Comfort
8.6Crew
7.5Entertainment
7.0Food
8.1Boarding
Airline reviews

Boarding was easy. The seats are small and fairly uncomfortable

8.0 ExcellentNicole, Mar 2026
LGB - OAK
Read more Southwest reviews

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.

No food or entertainment, just a quick 40 minute flight. A little bumpy due to Santa Ana winds but pilot has no control over that. Good flight and landing!

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

Mediocre. Boarding is now unpleasant. The employees, once friendly and nice, are now regularly speaking sternly to passengers, badgering them to do things right so they can take off on time and gate check bags because they don't have enough overhead bin space. The pretzel snack was crushed flat and broken into even smaller pieces, which happens frequently lately. Drink service was suspended before they reached my row.

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

3 hour delay. Had to change plans and was still delayed.

The staff was very friendly, professional, and courteous. The overall flight was a great experience.

The flight crew was extremely rude and especially not helpful when our flight was delayed.

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

This trip did not start off well. The inbound flight was delayed about 20 minutes. Then, after initial onboarding, the passengers had to deplane due to a mechanical problem. That took about 30 minutes to fix and be cleared. Then, reboarding was chaotic. It took a long time to sort passengers and two passengers on standby were ticketed but there was no seat. So, they had to deplane. One of the flight crew was trying to help passengers figure out a place to put their carry-on bags and that took more time. In the end, our scheduled 10:30 am departure did not actually take off until about 12:05 pm CST. The flight itself was long but we got to Houston. Some passengers missed their connecting flights and had to rebook. Not the best of flights I've had.

We were delayed for about an hour from taking off due to traffic control procedures at the destination airport. But once in the air, the flight went well. The crew members were great and provided cabin service despite moderate turbulence during much of the flight.

Short flight, but no drink/snack service. The flights both going and coming were delayed.

Not being stranded in Chicago for her airport to 11:30 tomorrow morning the 3rd

I was fully checked in the prior night and i was unchecked and then didn’t have a seat when I boarded. Instead of an aisle seat, I was out in the middle seat of the very last row of the plane.

In overall it was a good experience, the only down point was that the entertainment screen was working properly.

They lost my luggage, so, not happy. The crew was nice but my suitcases never made it, still trying to find out what happened!

I understand weather is an issue, but making us chase our plane down at five scheduled gates across three terminals in an airport the size of O'Hare was unfair. They'd have probably been better off to leave gates as TBD until the inbound plane is in final approach instead of running us all over the place. Also, props to the consistently-unprepared ground crew in Richmond for once again leaving my lane parked short of the gate because they couldn't have a crew in place on time with 2 hours notice...

cabin crew was OK, food was OK, the trip from the US to Munich was actually pretty bad comfort wise. Noisy aircraft, lights never dimmed even in Business class (night flight) barely sufficient amenities for the price. I have millions of miles with United but TBH American is gaining ground and Delta has always been marginally better then United although on paper United has more longes and cheaper upgrades.

Essy to get on. The hostess gave very little pop, the plane was late getting in, and we are still waiting for our bags. This sucks. :/

The gate got changed several times and the flight was delayed over an hour. Awful experience

American continues to decline in their customer service and its beyond disappointing.

It was an older plane. First Class was not especially roomy or comfortable. It was a short flight so there were no meal but they did offer mixed nuts which used to be normal but now is rare. Crew member was very polite and professional.

Smooth flight. From the early boarding and all were on board before departure time and arrived early in ONT. Great crew. Thank you!!!!

Flight to Tampa was delayed taking off due to plane arriving late but no other issues

As previously stated the delay I experienced flying from Wichita to Chicago caused a host of issues. When I finally was able to be booked on the last remaining American flight from Chicago to Cincinnati, the gate changed four times with the last change occurring very near the scheduled boarding time. While I didn't have a problem moving from gate to gate, I did notice and make note of others that had mobility issues and had to move each time for the gate change.

Maintenance took a very long time and then we were in a holding pattern. While a one-off maintenance issue is standard, there were delays on both of my flights for this trip based on maintenance issues with the planes, which delayed both flights over 45 minutes. Thankfully, I didn't have any connections but it wasn't an experience that would make me pick AA if I have other options.

No Snacks or Entertainment. The flight was short, snacks should still be given.

See prior comment about how Kayak mishandled my reservation and delayed my arrival by 6 hours.

Boarding delayed 20 minutes for no reason, no wifi, in flight entertainment, or snacks / waters?

More inflight connection. And leg space is horrible. And the paying for baggage I'd ridiculous!!!

My flight was originally from SAT to MCO connecting from MCO to ORD. We got diverted to ATL and than Frontier staff there was sooo un helpful first they said they couldn’t give us any accommodation since our flight first got delayed that cancelled and now it’s 221am and I am still in ATL since they said they need to create a new flight my final destination is ORD and I have been delayed twice and cancelled. With no real help the frontier app didn’t work no email updates over all such a horrible experience

There's no seats that lean back with little leg space i wad uncomfortable the entire flight. Your charges for extra baggage is despicable and costly!!

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

Flight was canceled. Most upsetting was message from Kayak, stating that the flight was canceled and click with Kayak for details regarding rebook, refund details. THERE'S NO INFORMATION PROVIDED BY KAYAK EXCEPT THAT FLIGHT IS CANCELED. AND NOW THIS SURVEY TO FIND OUT HOW WAS THE FLIGHT !!!!!!!

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

Our flight was canceled. I will never use Kayak nor Frontier for travel again. The entire experience was a headache.

Better than expected. Staff were friendly and nice on both flights.

Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.

i was unable to check in the flight. refund requested

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

Information on your arrival and departure airports