Cheap flights from Chicago to Los Angeles from $53
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Chicago to Los Angeles departing on 9/4. 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 Chicago to Ontario
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How to get the cheapest flight ticket from Chicago to Ontario
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 Chicago and Ontario?
What is the cheapest month to fly to Ontario?
In general, November is the cheapest month to fly from Chicago to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $148. If you aren’t able to travel during the month of November, then book flights to Ontario from Chicago during September instead. Flights to Ontario in September, while not as cheap as those in November, still average around $166.
What is the cheapest day to depart on your flight to Ontario?
The cheapest day to depart on your flight to Ontario is on a Tuesday when prices can be found for as low as $330. This is often the case because there is less demand to fly during this day of the week. When flying out on a Monday, the most expensive travel day of the week, you can expect to see flight prices from Chicago to Ontario for around $485.
What is the cheapest time of day to depart on your flight to Ontario?
In the evening is the cheapest time of day to fly from Chicago to Ontario when you can find flight prices for as low as $317. Flying to Ontario in the evening is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the afternoon when prices are $449 on average. Flights to Ontario from Chicago in the afternoon are generally more expensive because this time of day is more convenient for travelers’ schedules.
What is the cheapest Chicago to Ontario flight route?
Fly from Chicago O'Hare Intl to Ontario for the best Chicago - Ontario flight prices
How far in advance should I book a flight to Ontario?
You are more likely to see cheaper flights to Ontario from Chicago when booking weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $312 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from Chicago for as low as $254 on momondo.
What cabin class options are available on Chicago to Ontario flights?
There are 3 cabin classes available to choose from on Chicago to Ontario 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 Chicago to Ontario flights?
You could potentially save up to 23% on your flight if you consider stops on a Chicago to Ontario flight.
How have Chicago to Ontario flight prices changed over time?
As of July 2025, prices for Chicago to Ontario flights are approximately 17% cheaper when compared to flights at the same time last year.
What is the cheapest airline that flies from Chicago to Ontario?
Frontier is the most popular carrier operating from Chicago to Ontario
What airlines fly to Ontario?
American Airlines, Spirit Airlines and United Airlines are the top three most popular airlines that fly to Ontario from Chicago 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 Ontario. Keep in mind that there are 9 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.
How many flights depart from Chicago to Ontario on average per day?
As of July 2025, there are 1 flights per day flying from Chicago to Ontario. The most common time of day flights depart is 12:00PM, with 69% of flights taking off in the afternoon.
How many flights depart from Chicago to Ontario on average per week?
As of July 2025, 10 flights take off from Chicago and land in Ontario each week. The most common flight departure day for this route is Mon, with 30% of weekly flights taking off on this day.
When to book flights from Chicago to Ontario
Cheap Chicago to Ontario (CHI to ONT) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Chicago to Ontario
How far is Chicago to Ontario by plane?
The distance between Chicago and Ontario is about 1710.7 mi. In terms of flight time, this usually takes a little over 4h 10m.
When did momondo last update prices for flights from Chicago to Ontario Airport?
Prices for flights from Chicago to Ontario Airport refresh daily.
How many operators does momondo search for flights from Chicago to Ontario Airport?
The number of operators available for flights from Chicago to Ontario Airport is 5 as of July 2025.
How old do you have to be to fly from Chicago to Ontario Airport?
The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Chicago to Ontario Airport.
What documentation or ID do you need to fly to Ontario Airport?
The travel and health documents required for your trip to Ontario Airport 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 Ontario Airport. 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 Chicago to Ontario?
Based on momondo bookings for flights between Chicago and Ontario, the leading plane model is Airbus A321neo, making up 23.23% of the total bookings. Other popular models include Boeing 737 MAX 8 with 14.17%, Boeing 737-800 with 13.78%, and Airbus A321 (sharklets) with 13.39%.
What is the most popular airline from Chicago to Ontario?
Based on momondo bookings for this flight route, the most popular airline on flight routes from Chicago to Ontario is Frontier (40% of total bookings). The next most popular airlines are Southwest (23%), American Airlines (17%), and United Airlines (12%).
Best airlines flying from Chicago to Ontario
Compare and see reviews for airlines that fly from Chicago to Ontario with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $122 | Free Cancellation | Rating 5.9 3,286 reviews | |||
| PriceFrom $231 | Free Cancellation | Rating 7.2 10,000 reviews | |||
| PriceFrom $237 | Free Cancellation | Rating 7.4 8,861 reviews | |||
| PriceFrom $246 | Free Cancellation | Rating 8.0 7,982 reviews | |||
| PriceFrom $246 | Free Cancellation | Rating 8.0 4,266 reviews |
Southwest Flights From Chicago to Ontario
Across 6 Southwest flights from Chicago to Ontario this week, the average price was $477, with the best Southwest deals starting from $246 round-trip. 4,266 users have rated Southwest on momondo, with an average score of 8.0/10.
United Airlines Flights From Chicago to Ontario
Another popular option for Chicago to Ontario flights is United Airlines (7.4/10, 8,861 ratings). United Airlines flies from Chicago to Ontario around 4 times per week, with deals starting from $237 round-trip and rising to an average price of around $405.
Why use momondo?
Why should I use momondo to find a flight deal from Chicago to Ontario?
momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Chicago to Ontario. momondo saves you time and could save you money on your trip.
Can I find flights from Chicago to Ontario with flexible booking policies on momondo?
All flight searches from Chicago to Ontario on momondo can be filtered to show those which offer flexible booking policies.
How can momondo help me find flights from Chicago to Ontario?
momondo helps you find the best flight between Chicago and Ontario by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.
I’m not ready to book a flight from Chicago to Ontario right now. Can momondo alert me if prices change?
If you are simply researching potential flights to Ontario, momondo offers a useful price alert feature which will track prices for flights to Ontario from Chicago and alert you when they change.