$53 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 1/6. 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
0 bags

Search hundreds of travel sites at once for deals on flights to Illinois

 
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.
In the last 7 days travelers have searched 47,946,175 times on KAYAK, and here is why:

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Best Illinois Flight Deals

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

Chicago
Chicago1 stop$108
Moline
Moline1 stop$368
Peoria
Peoria2 stops$438
Bloomington
Bloomington1 stop$599
St. Louis
St. Louis1 stop$108

Good to know

Low season

February

High season

June

Cheapest flight

$53
Best time to beat the crowds with an average 33% drop in price.
Most popular time to fly and prices are also 6% lower on average.
Flight from Ontario to St. Louis

FAQs - booking Illinois flights

  • 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 to Illinois 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 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 to Illinois 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 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 to Illinois from Ontario 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 $228 one-way - $416 round-trip
  • Morning departure is around 19% cheaper than an evening flight, on average*.
*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.
8.2
China AirlinesOverall score based on 778 reviews
8.0Entertainment
8.6Crew
8.3Boarding
8.0Comfort
7.8Food
Airline reviews

Airline itself is great. While food was being taken off of my tray my beer spilled which was a total accident and I wasn’t upset about that, what was frustrating was I had to ask for towels to clean up and wipe my leg. It would have been left as is if I hadn’t.

4.0 OkayAnonymous, Sep 2024TPE - SEA
Read more China Airlines reviews

Airline itself is great. While food was being taken off of my tray my beer spilled which was a total accident and I wasn’t upset about that, what was frustrating was I had to ask for towels to clean up and wipe my leg. It would have been left as is if I hadn’t.

Bars and restaurants in Taipei close early. The lounge isn’t very good, but better than the public areas.

The food was the only thing that could have made the experience even better. Everything was stellar but the food. The staff was superb. I’ve been flying with ANA for years as my go-to and I think I may have found my new favorite. 😍

Short lay over. Seat assignment was terrible. Was traveling as a family and end up being seated separately. Will not use underpricer ever again.

Unable to set seat assignment. Got a call from presumably “China airlines representative” but was asking for an exorbitant amount for the seat assignment. Was traveling as a family end up being assigned to different seats as a result. Will never use underpricer again.

Not many selections for entertainment. Bulk head seats are no longer available with out fee at the counter. That’s pretty lame.

All of the staff were very helpful, polite I was very satisfied with China Airlines The food was normal for airlines but I’m sure they could do better

Everything was efficient. Good leg room. Food was good. Staff were friendly.

I would have liked to know how to order a special meal (for medical purposes) before the flight.

The flight who provided services on my row had some not-nice attitude and not smiling at all.

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 was a loud squeaky sound the whole time we were flying.

I usually have a positive experience with Delta. Complimentary upgrades are always nice!

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.

The seats on the aircraft are like sitting in a rock. During the boarding process they recognize Active Duty Military, why don’t they recognize Retired Military. I’ve always preferred Delta, this flight confirmed why I still prefer Delta.

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

The staff was very friendly. The seats seemed quite small. Overall the flight was pleasant.

It was literally one of the worst travel experiences ever. My flight got delayed by over an hour and there was no communication of this from the gate staff. I realized it by checking the screen periodically. Once on board the flight attendants continued to serve alcohol to a man who was clearly already drunk and that was making a bunch of commotion. Never again will I fly United!

Charging and entertainment didn't work. The meal was horrible. They only came by with the drink cart one time for the 8 hour flight. They did come by with water a couple times.

Exceptional, I’d like to specifically recognize Robert for his outstanding customer service. He is professional, pleasant, and personable.

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.

VERY disappointed at the agent checking in my luggage. I know that the weight limit is 23 kg, a little over 50 pounds (50.71 pounds). Yet the agent kept repeating "50 pounds". So I said, the limit is 23 kg, and she had the audacity to say 'no, it is 22 kg!" Imagine my surprise. Was she ignorant or was she poorly trained? Not sure. The boarding process was pretty good. The speakers were loud enough so I still could hear them despite inconsiderate passengers continuing to speak while the announcements were going on. During the flight, the teenage girl sitting behind me kept pressing her feet to the back of my chair. I turned around several times, yet she did not get the hint. I did not make a fuss since I sense I had a bad streak that night with AA, so I just did the best I can to lean forward and not let that bother me.

This flight was fine but had no time to breathe as the connection was late from Sea to ORD.. Super stressful. If we checked bags, the trip would have been very distressed.

Seats were very uncomfortable. I paid extra for a seat with more leg room, the seat was no different than a seat at the back of the plane. Flight attendant was rude.

Stop changing gates at sfo. When you are elderly going back for it’s not fun.

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.

There was no easy way to check in. I don't want to install an app to checkin. I will use alaska from now on because they have a web check in method that is easy.

Horrible! The short distance flight ended up taking 5 hrs! There was a 3 hr delay for the flight to take off and there was a 70 min wait on the tarmac for some bogus reason that the pilot said the gate he was supposed to board was taken up. After a 30 min wait he said the plane that was supposed to push out of the gate called a medical emergency and 40 min later he ended up boarding another gate. For the initial 3 hr delay there was no information/alert about the gate or delay in the app or the boards up until the boarding time and even beyond! Had to walk all the way to the end of the terminal to find the frontier staff to ask what was going on. Avoid this airline at all costs! If you have carryon bags or checked bags , their prices come equivalent to the prices of more reliable airlines. They are the worst in timeliness at 60% (reported as delayed) this year (check the data) by a high margin even compared to the second worst airline. If you are ok with having a miserable flight experience with the odds close to flip of a coin, feel free to try them. If you value your time , money and flying experience, stay away.

Allowed me to chose my seat without extra charge (I purchased full-price ticket) and boarding was in group1. Didn't even serve water.

I went to the Frontier counter in San Jose at 1030am or so on Sunday 10/13/24 to see if I could get an earlier flight to San Diego in lieu of my reserved 630pm flight. One thing led to another, and I was able to obtain an open seat for about $ 56. on the earlier flight. Fine. Then the agent asked if I "was checking a bag". Not knowing that carry-ons cost extra per Frontier policy, I thought that she meant a regular checked bag. Therefore, I said no. Once I got to the gate, the same gate agent who sold me a ticket told me that I had to pay $99 for a carry-on, and that all bags were extra on Frontier. Having never flown on Frontier, I was not aware of this. Part of the issue was that she was not a native English speaker, so there was a miscommunication as to what "bag" meant. I would have preferred for her to have clearly let me know at the front counter that any bag including a carry-on cost $99. It would have had the same outcome, as I had to take my carry-on. But it got hectic at the last minute at the gate itself. The baggage policy should have mentioned "including carry-ons" when we first spoke.

Most horrible airlines. Please avoid it. It's ok to spend $50 extra for delta, united or Alaska

Every day about it was very different all the boarding pass where all wrong l miss flight no refund all crazy

Staff members pretty horrible when boarding. No care for customers

The trip was good but the last minute changes I didn’t like because I had already talked to the attendee and they didn’t help me with my ticket I was having trouble checking in and when the time was up they help me but charge me for that and last minute luggage it was a small bag. After I was in the airplane I realized you were charging because the flight was almost empty and you have to get the money some how. Thanks for everything.

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.
12/5Do
1 stopFrontier
9h 30mONT-STL
12/7Sa
1 stopFrontier
6h 58mSTL-ONT
$108
2/6Do
1 stopFrontier
11h 10mONT-ORD
2/12Mi
1 stopFrontier
10h 02mORD-ONT
$108
1/15Mi
1 stop
14h 56mONT-ORD
1/19So
2 stops
41h 59mORD-ONT
$201
2/4Di
1 stopDelta
6h 12mONT-ORD
2/18Di
1 stopDelta
6h 33mORD-ONT
$256
1/29Mi
2 stopsDelta
10h 14mONT-MDW
2/4Di
1 stopDelta
7h 50mMDW-ONT
$261
1/24Fr
2 stops
10h 45mONT-STL
1/26So
1 stop
12h 40mSTL-ONT
$276
1/1Mi
1 stopAmerican Airlines
7h 16mONT-ORD
1/6Mo
1 stopAmerican Airlines
6h 50mORD-ONT
$307
1/18Sa
2 stopsAmerican Airlines
10h 13mONT-STL
1/21Di
1 stopAmerican Airlines
6h 53mSTL-ONT
$311
12/31Di
1 stopUnited Airlines
6h 10mONT-ORD
1/3Fr
1 stopUnited Airlines
7h 30mORD-ONT
$332
12/28Sa
1 stopUnited Airlines
9h 04mONT-ORD
1/3Fr
1 stopUnited Airlines
7h 30mORD-ONT
$336

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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.
1/6Mo
1 stopFrontier
5h 24mONT-STL
$53
1/13Mo
1 stopFrontier
8h 47mONT-MDW
$54
1/11Sa
1 stopAmerican Airlines
6h 25mONT-ORD
$109
1/18Sa
2 stopsAmerican Airlines
9h 28mONT-ORD
$114
12/25Mi
1 stopUnited Airlines
6h 10mONT-ORD
$119
12/26Do
1 stopUnited Airlines
8h 09mONT-ORD
$123
12/25Mi
1 stopDelta
7h 11mONT-MDW
$128
12/24Di
1 stopDelta
9h 01mONT-ORD
$128
12/10Di
1 stopAlaska Airlines
7h 54mONT-ORD
$142
3/5Mi
1 stopAlaska Airlines
10h 00mONT-ORD
$143

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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.
11/26Di
multi-stopFrontier
6h 28mONT-MDW
11/28Do
multi-stopFrontier
22h 25mMDW-ONT
$292
11/26Di
multi-stopFrontier
6h 28mONT-MDW
12/6Fr
multi-stopFrontier
12h 19mMDW-ONT
$318
11/26Di
multi-stopFrontier
6h 28mONT-MDW
12/4Mi
multi-stopFrontier
17h 29mMDW-ONT
$323
11/23Sa
multi-stop
7h 09mONT-ORD
11/25Mo
multi-stop
9h 16mORD-ONT
$428
11/21Do
multi-stopDelta
6h 40mONT-ORD
11/27Mi
multi-stopDelta
6h 53mORD-ONT
$457
11/26Di
multi-stopDelta
5h 42mONT-STL
12/3Di
multi-stopDelta
7h 56mSTL-ONT
$477
11/24So
multi-stopUnited Airlines
6h 27mONT-ORD
12/4Mi
multi-stopUnited Airlines
9h 48mORD-ONT
$604
11/21Do
multi-stopUnited Airlines
7h 37mONT-ORD
11/22Fr
multi-stopUnited Airlines
10h 03mORD-ONT
$608
11/22Fr
multi-stopAmerican Airlines
7h 45mONT-STL
11/25Mo
multi-stopAmerican Airlines
6h 05mSTL-ONT
$1,011
11/23Sa
multi-stop
13h 02mONT-ORD
11/27Mi
multi-stop
31h 21mORD-ONT
$1,193

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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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