$52 Find Cheap Flights from Ontario to Illinois

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 Illinois departing on 2/25. 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.
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These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Illinois.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Illinois.
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Best Illinois Flight Deals from Ontario

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours

Chicago
Chicago1 stop$108
Moline
Moline1 stop$314
Peoria
Peoria2 stops$395
Bloomington
Bloomington1 stop$537
St. Louis
St. Louis1 stop$110

Good to know

Low season

February

High season

June

Cheapest flight

$52
Best time to beat the crowds with an average 23% drop in price.
Most popular time to fly with an average 2% increase in price.
Flight from Ontario to Chicago Midway Airport

FAQs - booking Illinois flights

  • How long is the flight to Illinois from Ontario?

    Flights to Chicago4h 07m
  • What is the cheapest flight to Illinois from Ontario?

    The cheapest ticket to Illinois from Ontario found in the last 72 hours was $52 one-way, and $108 round-trip. The most popular route is from Ontario to Chicago Midway, and the cheapest round-trip airline ticket found on this route in the last 72 hours was $52.

  • Which airlines fly to Illinois?

    Southwest flies most frequently to Chicago Midway from Ontario.

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

    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 Illinois.

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

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

    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 from Ontario to Illinois with an airline and back with another airline.

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

    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 from Ontario to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

Top tips for finding cheap flights to Illinois

  • Looking for a cheap flight? 25% of our users found tickets from Ontario to the following destinations at these prices or less: Chicago $229 one-way - $386 round-trip
  • Book at least 1 week before departure in order to get a below-average price.
  • High season is considered to be July, August and September. The cheapest month to fly from Ontario is February.
  • Morning departure is around 30% cheaper than an evening flight, on average*.
See more tips
*Average of the lowest prices shown in KAYAK’s search results for departures within the next 30 days

Top 5 airlines serving from Ontario to Illinois

 
See real verified KAYAK customer reviews for airlines flying from Ontario to Illinois. 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 Illinois? 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.
8.1
SouthwestOverall score based on 4662 reviews
7.2Food
8.1Comfort
8.7Crew
8.2Boarding
7.7Entertainment
Airline reviews

Flight was awfully bumpy and landing was a bit jolting. I was in the restroom when snacks and drinks were served and was not asked if i wanted any. I had to ask for water finally.

10.0 ExcellentRachel, Jan 2025TPA - MDW
Read more Southwest reviews

Flight was awfully bumpy and landing was a bit jolting. I was in the restroom when snacks and drinks were served and was not asked if i wanted any. I had to ask for water finally.

Employees were kind and funny, as always! Flight was late but no announcements were made for people with tight connections to help them transition quickly. No service due to turbulence.

I recently flew Southwest from San Jose to Honolulu. I was very impressed with the flight crew, especially the flight attendant in charge of the front of the plane. She came through the aisle at least five times for drinks and water, and two times for snacks. I have not seen such service since I flew first class. Also, for the first time, they gave us the correct baggage claim number, and the luggage came out quickly. I can't wait for Southwest to have assigned seating! I absolutely hate the Cattle Call boarding procedure and the mad dash to get seats and overhead bins. However, the boarding was efficient.

We had a nice flight. Boarding was easy, our seats were comfortable and the on board service was pleasant.

Service was great, boarding and exiting went smoothly, and the flight was very pleasant.

Was as expected. Crowed planes. Too many carryons delaying takeoff. But the ride only took an hour and saved me a lot of time SFO is a not a great airport.

Was as expected. Crowed planes. Too many carryons delaying takeoff. But the ride only took an hour and saved me a lot of time SFO is a hell hole of an airport. It is the new LaGuardia. Everything Cobbled together. Security gates closed. Terri directional signage

I used to fly SWA all the time. I know the crew has their little acts that are often fun, and entertaining. On this flight one of the crew was just not nice. Very surprising.

I like that it was on time and the staff was friendly.

The plane arrived 25 minutes late, and the Wi-Fi was slower than it usually is.

It was terrible, if they ran flights on time it would make a big difference.

Delta seems to be improving in many areas, except they are super bad with the food available. Bring back normal food service on long flights.

I actually received a notification from kayak on email but not one by text from Delta when my departure gait changed and I almost missed my flight

New boarding doesn't make sense. Filling front first is slow.

Delta flight was great from the check in all the way to arrival. However, I had a very bad experience. I requested a wheelchair and the wheelchair employee that went to pick me up from the plane in Boston to bring me to the baggage claims told me I have to pay him. I was under the impression that it was a free service and I usually give tips but the person forced me to pay and since I said no because I was upset with his demand when my daughter walked in to pick me up he demanded payment from my daughter who paid him thinking maybe now it is a charged service.

Horrible. Grateful to be alive but spent 13 hours at airport only to return back to my familys house and flight changed to next day. They tried to fix a part on plane, had no back up plane and after 10 hours , reattempted the flight and it STILL wasn't fixed. We got a meal voucher and rescheduled flight but there should be some other compensation for the 15 hours spent in airport

5 hour delay. They blamed the weather but it was the computer issues they had been dealing with for days.

My seat was changed at the last minute and I was moved to the last row, right next to the bathroom despite selecting my seat well in advance. I was also made to check my carry on due to space but when I got on the plane there was significant empty overhead space. Picking up my carry on from the luggage carousel added time to my trip which had already been extended due to delay.

There was plenty of overhead room but half of the passengers were told they had to check their carryon bags. My partner and I checked in as early as possible and our seats were split across the aisle.

Flew first class so everything was great. But maybe because the flights were red eye, no meals were served, just chips. I flew Alaska Air 1st class at 9PM (2 hour flight) and they served beef short rib sliders!

There's just no way to sit fully upright and comfortably in these seats. There needs to be 2 more inches of room, and that's not something that only one person on the flight needs - the whole flight needs 2 more inches of room. If that means you sell 6 less seats, so be it. It's too close for anyone. Forcing people to pay for "premium" economy just to get "barely enough space to breathe" isn't really an answer to that.

The crew were very nice. The Chocolate is good and v there’s no entertainment. Thanks

The crew were very nice. I would have appreciated a pillow for comfort. I had a special meal that was sloppy, but the salad was great. Thanks

The plane was in Moline all night. Consequently, we assumed an on time departure at 8:15am. Unfortunately, and as is the normal case with United in Moline, we departed 2.5 hours late. When the crew came, it was discovered that there was very little heat in the plane. Seems this should have been checked hours before the crew arrived. Then when we boarded and the plane was to be de-iced, the United de-icing truck was not working! We awaited the American Airlines truck. All of this caused us to miss our connection in Chicago. My suggestion is never take United Airlines flight from Moline. We have been disappointed 80% of the time and have vowed to not take United again from Moline.

Flight was delayed two hours. No snacks and no tv screens. My bag got stuck in Chicago

The aircrew was solid, the flight was chill, I had no issues. The gate agent was not the best. I was trying to use a military bag upgrade to move my bag from under the seat to the overhead bins and he told me there’s no overhead bins on the plane, argued with me why booking put a military member in basic economy (I don’t really understand this) and made it an issue to even try to help me stating I’d have to call reservations to get a bag upgrade. When every other agent with United can add it at the gate, this man couldn’t be bothered.

They canceled our flight and left us stranded to figure it out

Everything was very good. Was able to change a make run flight leaving on direct earlier in the app -seamless!!! Well done

Being stick waiting for gate at ORD cause me to almost miss my connecting flight…being deaf United made no no effort to keep me updated as I couldn’t hear the PA

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.

Seating was horrible. Small seats. Access to flight information and extras very iser unfriendly. Kept losing internet after paying for it. Staff in madison was as unprofessional and unhelpful.

Delayed due to no crew. On a major holiday travel day.

Other than being delayed 5.5 hours and having to get a hotel because I missed my connecting flight, it was an okay flight. No in-flight Wi-Fi or entertainment.

It was nice being on a flight that had working wifi. The boarding was quick - why don’t all airlines have small boarding groups window to aisle? Makes so much sense!!! I was disappointed to be the first person stopped to have to gate check my carryon. Especially when there was plenty of overhead space at the back! But I get it…keeps it moving. Crew was nice.

The flight from Buffalo to Chicago was on an older and smaller plane. Seating was tight. Looking closely at the interior of the aircraft there were definitely signs of aging and wear.

The flight encountered a delay exceeding 4 hours. The food voucher issued was valued at $12, insufficient to cover our meal expenses. Consequently, I was unable to take my medication, leading to a drop in blood sugar levels and exacerbating my anxiety.

Airplane was cold. Flight attendants were rude. Phone charger did not work. No food available.

3hour delay In the last 3 months i had 3 flights and 2 of these had a more than 2:40 hrs delayed

My initial flight to ORD was extended without reason. We circled the airport a few time and then drove on the ground for at least 20 minutes. These kinds of delays are annoying but somewhat expected… it would be nice if the crew would make an announcement to give updates on how long we could expect to be delayed.

The flight was uneventful. What was a problem was I was delayed getting home one entire day because the flight from Sacramento was delayed. That made getting to my connecting flight impossible. I had to stay another night at the hotel and incur that expense as a result.

After waiting several minutes to be acknowledged by 3 employees on their phones, was told we had missed our flight because the doors were closed at that literal moment. Had they given any actual service or help while we were standing there we would have been on with time to spare. More than 10 people were turned away in this fashion claiming there was no way they could let us on the plane, even though it was still sitting connected to the terminal. After the desk agents let us know they didn't care about the situation we were forced to pay more than twice the price of our original tickets as no credits were given for the price of the "missed" flight. And the icing on the cake was after being treated poorly, fleeced for another few hundred dollars for new tickets? We waited on the next plane for 25 minutes passed the "doors closed" time, letting almost an extra dozen passengers on board. You're company has lazy, disinterested employees and your lack of any real help will ensure this was the first and last time we fly Frontier. Awful.

I loked walking out on the tarmac to board and no first class. I didn't like that they have no snacks or onboard wifi to bide your time.

It was a redeye flight, so every passenger just wanted to sleep, but through the entire flight, the flight crew made announcements over the loudspeaker at maximum volume every few minutes making sleep impossible. For example: it’s 2am, and the crew decides to give an extremely detailed announcement about snacks and beverages for sale. And 3am is the perfect time to wake up everyone with a lengthy announcement about how to get a coffee refill and how to take advantage of new offer from frontier for a credit card.

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.. .

terrible cascading delays and unhelpful customer service. uncomfortable plane. crew was great, however!

With frontier you get what you pay for. The flight was two hours late. It’s a tight fit for the number of people they bring but you get to where you’re going cheap. Sometimes that’s more important than a nifty drink and cool TV..

Charges unexpected. For seat that didnt recline. Please reverse extra seat and carryon charge. Bad business that is a bait and switch.

We had an awful experience getting our bags checked in. Frontier’s check in on the app manipulated us into buying the business package because that was the only option available for a checked bag which included two checked bags per person which we did not need. Upon arriving to the airport, we stood in line for what seemed like forever at the baggage check in and there was no one available at the counter. We were first in line and we were afraid we were going to miss our flight due to the baggage attendant being late. After realizing there were a lot of other people waiting at the baggage check in and no one available. I reached out to Frontier and could not get any customer service so I had to call the airport to page the baggage attendant to send someone to the counter to check in our bags before we were able to go through security , I finally spoke to the attendant at the counter and explained to her that we had to pay for two checked bags person a total of six bags when we only had a total of three bags between three people she said to reach out to Frontier and they would issue a refund for the three bags that we paid for and did not need. I reached out to Frontier which I was not able to reach anybody by phone so I had to go through their automated chat feature, which sent me around in circles until I finally reached a representative to assist me. I explained to them what happened and they explained that they were not able to assist me. I continued to push the issue with them as this was very frustrating and they finally put in a customer service ticket where we were issued a flight credit and we were so disappointed because after this experience, we NEVER want to fly Frontier again, and we do not want a credit that we will not use. Frontier charged us almost $500 for us to check three bags which is absolutely absurd! The customer service agents were not able to offer anything else other than a flight credit and I do not feel like my frustrations were truly heard , we will never use Frontier Airlines again ! Truly Theft by Manipulation! They should be ashamed!

I couldn’t check in because the app didn’t work. It took 3 Frontier employees at the counter to get me checked in. Flight left 3 hours after departure time

Book cheap flights from Ontario to Illinois

Recent round-trip flight deals

 
These are the cheapest round-trip flights from Ontario to Illinois found on KAYAK in the last 72 hours.
2/27Thu
1 stopFrontier
5h 56mONT-MDW
3/3Mon
1 stopFrontier
8h 18mMDW-ONT
$108
2/15Sat
1 stopFrontier
5h 36mONT-STL
2/22Sat
1 stopFrontier
7h 05mSTL-ONT
$110
4/24Thu
1 stopAmerican Airlines
7h 46mONT-ORD
4/26Sat
1 stopAmerican Airlines
6h 56mORD-ONT
$247
2/26Wed
1 stopDelta
7h 15mONT-MDW
3/1Sat
1 stopDelta
9h 11mMDW-ONT
$257
3/5Wed
1 stopDelta
6h 06mONT-ORD
3/8Sat
1 stopDelta
8h 26mORD-ONT
$257
2/15Sat
nonstopSouthwest
3h 45mONT-MDW
2/17Mon
nonstopSouthwest
4h 30mMDW-ONT
$281
2/15Sat
nonstopSouthwest
3h 45mONT-MDW
2/19Wed
nonstopSouthwest
4h 30mMDW-ONT
$310
3/11Tue
1 stopUnited Airlines
9h 06mONT-ORD
3/18Tue
1 stopUnited Airlines
8h 22mORD-ONT
$332
4/17Thu
1 stopUnited Airlines
6h 18mONT-ORD
4/22Tue
1 stopUnited Airlines
6h 33mORD-ONT
$337
7/18Fri
1 stopAmerican Airlines
7h 26mONT-ORD
7/22Tue
1 stopAmerican Airlines
5h 24mORD-ONT
$343

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Recent one-way flight deals

 
Only flying one-way? Below are some of the best one-way flight deals from Ontario to Illinois found on KAYAK in the last 72 hours.
2/25Tue
1 stopFrontier
21h 18mONT-MDW
$52
4/1Tue
1 stopFrontier
5h 44mONT-MDW
$54
3/12Wed
1 stopUnited Airlines
9h 06mONT-ORD
$119
2/25Tue
1 stopDelta
7h 15mONT-MDW
$129
2/19Wed
1 stopDelta
8h 43mONT-ORD
$129
2/20Thu
nonstopSouthwest
3h 45mONT-MDW
$141
2/28Fri
nonstopSouthwest
3h 45mONT-MDW
$151
7/2Wed
1 stopUnited Airlines
7h 25mONT-ORD
$161
3/15Sat
1 stopAmerican Airlines
8h 39mONT-STL
$176
3/1Sat
2 stopsAmerican Airlines
7h 24mONT-STL
$179

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Last minute flights from Ontario to Illinois

Last minute flight, train and bus deals

 
These last-minute flight deals are the cheapest flights found on KAYAK in the last 72 hours for flights from Ontario to Illinois that are departing in the next 10 days.
1/25Sat
multi-stopFrontier
17h 52mONT-MDW
1/28Tue
multi-stopFrontier
17h 32mMDW-ONT
$194
1/22Wed
multi-stopFrontier
26h 51mONT-ORD
1/31Fri
multi-stopFrontier
12h 46mORD-ONT
$220
1/26Sun
multi-stopDelta
7h 20mONT-MDW
1/29Wed
multi-stopDelta
7h 45mMDW-ONT
$481
1/26Sun
multi-stopDelta
9h 47mONT-MDW
1/29Wed
multi-stopDelta
7h 45mMDW-ONT
$487
1/26Sun
multi-stopUnited Airlines
6h 08mONT-ORD
2/11Tue
multi-stopUnited Airlines
8h 17mORD-ONT
$490
1/23Thu
multi-stopAlaska Airlines
9h 59mONT-ORD
1/26Sun
multi-stopAlaska Airlines
9h 31mORD-ONT
$518
1/24Fri
multi-stopSouthwest
6h 30mONT-ORD
1/26Sun
multi-stopSouthwest
9h 20mORD-ONT
$569
1/22Wed
multi-stopAlaska Airlines
10h 26mONT-ORD
1/23Thu
multi-stopAlaska Airlines
9h 26mORD-ONT
$584
1/26Sun
multi-stopUnited Airlines
6h 08mONT-ORD
1/29Wed
multi-stopUnited Airlines
15h 41mORD-ONT
$601
1/24Fri
multi-stopSouthwest
10h 30mONT-ORD
1/26Sun
multi-stopSouthwest
9h 20mORD-ONT
$619

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

Information on your arrival and departure airports

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