Cheap flights from Ontario to Chicago from $61
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 8/21. 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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Frontier flights from Ontario to Chicago
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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 cheapest month to fly to Chicago?
The month of November is, on average, the cheapest month to fly to Chicago from Ontario, with most prices found around $225. If you’re not able to fly to Chicago in November, then September is your next best option. Flight prices from Ontario to Chicago during September average around $260.
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 $359. 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 $468.
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 $287. In contrast, the most expensive time of day to depart to Chicago is at noon when prices are around $443.
What is the cheapest Ontario to Chicago flight route?
Fly from Ontario to Chicago Midway for the best Ontario - Chicago flight prices
How far in advance should I book a flight 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 $361 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 $271 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 17% 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 July 2025, prices for Ontario to Chicago flights are approximately 22% cheaper when compared to flights at the same time last year.
What is the cheapest airline that flies from Ontario to Chicago?
Frontier is the most popular carrier operating from Ontario to Chicago
What airlines fly to Chicago?
American Airlines, United Airlines and Spirit Airlines 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 42% of people opting to fly with this airline when traveling to Chicago. Keep in mind that there are 9 different airlines that fly to Chicago on a routine basis, so you have a few additional options to choose from.
How many flights depart from Ontario to Chicago on average per day?
As of July 2025, 1 flights take off from Ontario and land in Chicago each day. The most common flight departure time for this route is 7:00AM, with 90% 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 8 per week as of July 2025. The most frequent departure day is Mon, with 25% 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
How far is Ontario to Chicago by plane?
The straight-line distance from Ontario to Chicago is 1710.7 mi. 6h 33m 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 July 2025, there are 6 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 Airbus A321neo, making up 18.97% of the total bookings. Other popular models include Boeing 737 MAX 8 with 16.63%, Boeing 737-800 with 14.53%, and Airbus A320neo with 11.30%.
What is the most popular airline from Ontario to Chicago?
Based on momondo bookings for flights between Ontario and Chicago, the leading airline is Frontier, making up 29% of the total bookings. Other popular airlines include Southwest with 27%, United Airlines with 20%, and American Airlines with 16%.
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 $99 | Free Cancellation | Rating 6.3 8,086 reviews | |||
| PriceFrom $108 | Free Cancellation | Rating 5.9 3,286 reviews | |||
| PriceFrom $227 | Free Cancellation | Rating 7.4 8,861 reviews | |||
| PriceFrom $237 | Free Cancellation | Rating 8.0 4,266 reviews | |||
| PriceFrom $241 | Free Cancellation | Rating 8.0 7,982 reviews | |||
| PriceFrom $246 | Free Cancellation | Rating 7.2 10,000 reviews |
Southwest Flights From Ontario to Chicago
Southwest flight deals from Ontario to Chicago start from $237 round-trip. Over the 4 Southwest flights for this route in a normal week, average airfare is usually $443 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 $227, round-trip. It should be noted that an average United Airlines flight deal for this route in this time was higher, at $369 round-trip. United Airlines operates 4 flights out of Ontario into Chicago in an average week, so prices vary by time and availability. 8,861 United Airlines reviews by users on momondo have scored the airline at 7.4/10.
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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.