Cheap flights from Ontario to Chicago from $119
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to Chicago departing on 12/16. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Fly from
Fly to
Route
Depart
Return
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Mon 12/14
6:00 am-12:54 am
1 stop16h 54m
Chicago O'Hare Intl
Tue 12/15
7:25 am-10:45 am
1 stop29h 20m
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Wed 11/4
6:30 am-12:21 am
1 stop15h 51m
Chicago O'Hare Intl
Sat 11/7
6:30 am-10:42 am
1 stop6h 12m
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Sat 10/24
6:02 am-6:20 pm
1 stop10h 18m
Chicago O'Hare Intl
Sat 10/31
6:30 am-10:42 am
1 stop6h 12m
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Tue 11/17
6:00 am-5:37 pm
1 stop9h 37m
Chicago O'Hare Intl
Wed 11/18
8:59 am-4:38 pm
1 stop9h 39m
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Wed 11/4
1:35 pm-10:05 pm
1 stop6h 30m
Chicago O'Hare Intl
Sat 11/7
7:35 am-12:36 pm
1 stop7h 01m
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Sat 10/24
7:00 am-1:10 pm
Nonstop4h 10m
Chicago O'Hare Intl
Sat 10/31
4:15 pm-6:47 pm
Nonstop4h 32m
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Thu 10/29
11:55 pm-5:40 am
Nonstop3h 45m
Chicago Midway
Sat 11/7
10:25 am-12:45 pm
Nonstop4h 20m
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Tue 11/3
6:00 am-4:32 pm
2 stops8h 32m
Chicago O'Hare Intl
Tue 11/10
7:30 am-12:17 pm
1 stop6h 47m
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Thu 10/29
6:59 am-1:02 pm
Nonstop4h 03m
Chicago O'Hare Intl
Sat 11/7
2:30 pm-8:15 pm
1 stop7h 45m
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Thu 10/29
11:55 pm-5:40 am
Nonstop3h 45m
Chicago Midway
Sat 11/7
12:55 pm-7:05 pm
1 stop8h 10m
See travel insights to Chicago from
How to get the cheapest flight ticket from Ontario to Chicago
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the typical price of a round-trip flight between Ontario and Chicago?
Prices are currently low for flights on this route.
Typical prices usually range from $258 to $511.The lowest price recently found on this route was $198.
What is the cheapest month to fly to Chicago?
The month of January is, on average, the cheapest month to fly to Chicago from Ontario, with most prices found around $345. If you’re not able to fly to Chicago in January, then September is your next best option. Flight prices from Ontario to Chicago during September average around $384.
What is the cheapest day to depart on your flight to Chicago?
The cheapest day to depart on your flight to Chicago is on a Wednesday when prices can be found for as low as $408. This is often the case because there is less demand to fly during this day of the week. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Ontario to Chicago for around $512.
What is the cheapest time of day to depart on your flight to Chicago?
Our most recent data shows that the best time of day to fly to Chicago is in the afternoon. Flights from Ontario to Chicago during this time can be as low as $376. In contrast, the most expensive time of day to depart to Chicago is at noon when prices are around $541.
What is the cheapest Ontario to Chicago flight route?
Fly from Ontario to Chicago O'Hare Intl for the best Ontario - Chicago flight prices
How far in advance should I book a flight from Ontario to Chicago?
You are more likely to see cheaper flights to Chicago from Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to Chicago for around $406 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Chicago from Ontario for as low as $340 on momondo.
What cabin class options are available on Ontario to Chicago flights?
There are 4 cabin classes available to choose from on Ontario to Chicago flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.
Can stopping save me money on Ontario to Chicago flights?
You could potentially save up to 24% on your flight if you consider stops on a Ontario to Chicago flight.
How have Ontario to Chicago flight prices changed over time?
As of October 2026, prices for Ontario to Chicago flights are approximately 74% more expensive when compared to flights at the same time last year.
What is the cheapest airline that flies from Ontario to Chicago?
Delta is the most popular carrier operating from Ontario to Chicago
What airlines fly to Chicago?
American Airlines, United Airlines and Frontier are the top three most popular airlines that fly to Chicago from Ontario according to our data. American Airlines is the first choice among our users, with 41% of people opting to fly with this airline when traveling to Chicago. Keep in mind that there are 7 different airlines that fly to Chicago on a routine basis, so you have a few additional options to choose from.
Which airport is the most popular layover for flights between Ontario and Chicago?
Phoenix (PHX) was the most common stop: 67% of momondo users choosing 1-stop flights on this route connected there.
Which layover airport offers the lowest fares from Ontario to Chicago?
Flights via Las Vegas (LAS) offer the lowest average round-trip price of $144.
Which layover airport has the shortest travel time from Ontario to Chicago?
Flights connecting via Las Vegas (LAS) have the shortest average one-way travel time: 5h 40m.
Which layover airport has the shortest connection time from Ontario to Chicago?
Las Vegas (LAS) has the shortest average layover time for this route: 0h 45m.
How many flights depart from Ontario to Chicago on average per day?
As of October 2026, 2 flights take off from Ontario and land in Chicago each day. The most common flight departure time for this route is 7:00AM, with 50% of daily flights taking off at noon.
How many flights depart from Ontario to Chicago on average per week?
The number of flights available between Ontario and Chicago is 14 per week as of October 2026. The most frequent departure day is Mon, with 14% of weekly flights leaving on this day.
When to book flights from Ontario to Chicago
Cheap Ontario to Chicago (ONT to CHI) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Ontario to Chicago
Frequently asked questions about flying from Ontario to Chicago
How far is Ontario to Chicago by plane?
The straight-line distance from Ontario to Chicago is 1710.7 mi. 3h 45m is a normal flight duration for this route.
When did momondo last update prices for flights from Ontario Airport to Chicago?
Prices for flights from Ontario Airport to Chicago were last updated today.
How many operators does momondo search for flights from Ontario Airport to Chicago?
As of October 2026, there are 5 operators available to choose from for flights from Ontario Airport to Chicago.
How old do you have to be to fly from Ontario Airport to Chicago?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Ontario Airport to Chicago.
What documentation or ID do you need to fly to Chicago?
The travel and health documents required for your trip to Chicago can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Chicago. We always recommend checking with your airline or a trusted third party such as IATA to get advice.
What is the most popular plane model from Ontario to Chicago?
Based on momondo bookings for flights between Ontario and Chicago, the leading plane model is Boeing 737-800, making up 19.12% of the total bookings. Other popular models include Boeing 737 MAX 8 with 16.46%, Airbus A321neo with 11.82%, and Airbus A320-100/200 with 8.73%.
What is the most popular airline from Ontario to Chicago?
Based on momondo bookings for flights between Ontario and Chicago, the leading airline is United Airlines, making up 46% of the total bookings. Other popular airlines include Southwest with 29%, Frontier with 15%, and Delta with 7%.
Best airlines flying from Ontario to Chicago
Compare and see reviews for airlines that fly from Ontario to Chicago with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $131 | Free Cancellation | Rating 5.5 2,550 reviews | |||
| PriceFrom $253 | Free Cancellation | Rating 7.9 4,214 reviews | |||
| PriceFrom $258 | Free Cancellation | Rating 7.8 8,634 reviews | |||
| PriceFrom $274 | Free Cancellation | Rating 7.4 10,287 reviews | |||
| PriceFrom $276 | Free Cancellation | Rating 7.0 12,129 reviews |
Southwest Flights From Ontario to Chicago
Southwest flight deals from Ontario to Chicago start from $253 round-trip. Over the 7 Southwest flights for this route in a normal week, average airfare is usually $495 round-trip - but some users have found much cheaper deals with momondo.
United Airlines Flights From Ontario to Chicago
The best United Airlines deal for Ontario to Chicago flight tickets found on momondo in the last 72 hours was $274, round-trip. It should be noted that an average United Airlines flight deal for this route in this time was higher, at $447 round-trip. United Airlines operates 7 flights out of Ontario into Chicago in an average week, so prices vary by time and availability. 10,289 United Airlines reviews by users on momondo have scored the airline at 7.4/10.
Traveling to a place near Chicago?
Book flights to Chicago if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from Ontario to Chicago?
momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Ontario to Chicago. momondo saves you time and could save you money on your trip.
Can I find flights from Ontario to Chicago with flexible booking policies on momondo?
Yes. All flights to Chicago from Ontario on momondo can be compared and filtered by various policies on offer, including flexible booking.
How can momondo help me find flights from Ontario to Chicago?
Once you have performed a search for Ontario to Chicago flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.
I’m not ready to book a flight from Ontario to Chicago right now. Can momondo alert me if prices change?
Of course. momondo tracks the price of Ontario to Chicago flights. All you need is a valid email address and we will do the rest; it is that quick and easy.