What is the cheapest airline that flies from Ontario to Chicago?

Delta, Southwest, and Frontier are the most popular carriers operating from Ontario to Chicago

How many flights depart from Ontario to Chicago on average per day?

As of May 2026, 1 flights take off from Ontario and land in Chicago each day. The most common flight departure time for this route is 11:00PM, with 50% of daily flights taking off at noon.

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.

How many flights depart from Ontario to Chicago on average per week?

The number of flights available between Ontario and Chicago is 11 per week as of May 2026. The most frequent departure day is Mon, with 18% of weekly flights leaving on this day.

Which airport is the most popular layover for flights between Ontario and Chicago?

Denver (DEN) was the most common stop: 36% of momondo users choosing 1-stop flights on this route connected there.

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.

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.

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 42% of people opting to fly with this airline when traveling to Chicago. Keep in mind that there are 8 different airlines that fly to Chicago on a routine basis, so you have a few additional options to choose from.

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 May 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.

$99 Cheap Flights from Ontario to Chicago in 2026

Q: 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 $501 to $334. The lowest price recently found on this route was $277.

1 adult

0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

Find the cheapest flights from Ontario to Chicago

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

12:00 pm - 9:46 pm

ONT

MDW

7h 46m

1 stop

9:30 am - 6:01 pm

MDW

ONT

10h 31m

2 stops

$277Delta

Thu, Sep 24 - Tue, Sep 29

11:52 am - 11:55 pm

ONT

ORD

10h 03m

1 stop

12:30 pm - 9:48 pm

ORD

ONT

11h 18m

2 stops

$277Delta

Wed, Jun 3 - Sat, Jun 6

6:00 am - 8:32 pm

ONT

ORD

12h 32m

1 stop

9:37 pm - 10:05 am

ORD

ONT

14h 28m

1 stop

$278Frontier

Sat, Jun 6 - Mon, Jun 8

10:50 am - 8:32 pm

ONT

ORD

7h 42m

1 stop

5:29 pm - 5:52 pm

ORD

ONT

26h 23m

1 stop

$279Frontier

Wed, Jun 3 - Tue, Jun 9

6:00 am - 8:32 pm

ONT

ORD

12h 32m

1 stop

7:20 am - 3:08 pm

ORD

ONT

9h 48m

1 stop

$280Frontier

Wed, May 27 - Wed, Jun 10

1:50 pm - 12:59 am

ONT

ORD

9h 09m

1 stop

8:18 pm - 10:51 pm

ORD

ONT

4h 33mnonstop

$283United Airlines

Tue, Jun 2 - Sat, Jun 6

11:55 pm - 5:40 am

ONT

MDW

3h 45mnonstop

5:25 am - 9:10 am

MDW

ONT

5h 45m

1 stop

$283Southwest

Tue, Jun 2 - Sat, Jun 6

7:20 pm - 5:10 am

ONT

MDW

7h 50m

1 stop

3:50 pm - 5:55 pm

MDW

ONT

4h 05mnonstop

$284Southwest

Tue, Jun 9 - Wed, Jun 24

3:34 pm - 12:23 pm

ONT

RFD

18h 49m

1 stop

10:05 pm - 7:51 pm

RFD

ONT

23h 46m

2 stops

$332Multiple Airlines

Wed, Jun 24 - Mon, Jun 29

1:28 pm - 12:24 pm

ONT

RFD

20h 56m

1 stop

1:14 pm - 7:53 pm

RFD

ONT

8h 39m

1 stop

$392Multiple Airlines

Wed, Jul 22 - Sun, Jul 26

Frontier flights from Ontario to Chicago

Our best Frontier deals on Ontario to Chicago flight tickets

Frontier

Jun 6

ONT6:00 amOntario

12h 32m

1 stop

ORD8:32 pmChicago O'Hare Intl

Jun 8

ORD9:37 pmChicago O'Hare Intl

14h 28m

1 stop

ONT10:05 amOntario

$278

Frontier

Jun 3

ONT10:50 amOntario

7h 42m

1 stop

ORD8:32 pmChicago O'Hare Intl

Jun 9

ORD5:29 pmChicago O'Hare Intl

26h 23m

1 stop

ONT5:52 pmOntario

$279

Frontier

May 27

ONT6:00 amOntario

12h 32m

1 stop

ORD8:32 pmChicago O'Hare Intl

Jun 10

ORD7:20 amChicago O'Hare Intl

9h 48m

1 stop

ONT3:08 pmOntario

$280

United Airlines flights from Ontario to Chicago

Our best United Airlines deals on Ontario to Chicago flight tickets

United Airlines

Jun 2

ONT1:50 pmOntario

9h 09m

1 stop

ORD12:59 amChicago O'Hare Intl

Jun 6

ORD8:18 pmChicago O'Hare Intl

4h 33m

ONT10:51 pmOntario

$283

United Airlines

Jun 10

ONT6:05 amOntario

4h 15m

ORD12:20 pmChicago O'Hare Intl

Jun 17

ORD8:18 pmChicago O'Hare Intl

4h 33m

ONT10:51 pmOntario

$294

United Airlines

Aug 5

ONT1:50 pmOntario

9h 09m

1 stop

ORD12:59 amChicago O'Hare Intl

Aug 11

ORD5:30 pmChicago O'Hare Intl

4h 27m

ONT7:57 pmOntario

$305

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioChicago

ONT - MDW

ONTMDW

Ontario

Thu 9/24

12:00 pm-9:46 pm

1 stop7h 46m

Chicago Midway

Tue 9/29

9:30 am-6:01 pm

2 stops10h 31m

$277

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 6/3

11:52 am-11:55 pm

1 stop10h 03m

Chicago O'Hare Intl

Sat 6/6

12:30 pm-9:48 pm

2 stops11h 18m

$277

OntarioChicago

ONT - ORD

ONTORD

Ontario

Sat 6/6

6:00 am-8:32 pm

1 stop12h 32m

Chicago O'Hare Intl

Mon 6/8

9:37 pm-10:05 am

1 stop14h 28m

$278

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 6/3

10:50 am-8:32 pm

1 stop7h 42m

Chicago O'Hare Intl

Tue 6/9

5:29 pm-5:52 pm

1 stop26h 23m

$279

OntarioChicago

ONT - ORD

ONTORD

Ontario

Wed 5/27

6:00 am-8:32 pm

1 stop12h 32m

Chicago O'Hare Intl

Wed 6/10

7:20 am-3:08 pm

1 stop9h 48m

$280

OntarioChicago

ONT - ORD

ONTORD

Ontario

Tue 6/2

1:50 pm-12:59 am

1 stop9h 09m

Chicago O'Hare Intl

Sat 6/6

8:18 pm-10:51 pm

Nonstop4h 33m

$283

Quickest round-trip

OntarioChicago

ONT - MDW

ONTMDW

Ontario

Tue 6/2

11:55 pm-5:40 am

Nonstop3h 45m

Chicago Midway

Sat 6/6

5:25 am-9:10 am

1 stop5h 45m

$283

OntarioChicago

ONT - MDW

ONTMDW

Ontario

Tue 6/9

7:20 pm-5:10 am

1 stop7h 50m

Chicago Midway

Wed 6/24

3:50 pm-5:55 pm

Nonstop4h 05m

$284

OntarioChicago

ONT - RFD

ONTRFD

Ontario

Wed 6/24

3:34 pm-12:23 pm

1 stop18h 49m

Chicago Greater Rockford

Mon 6/29

10:05 pm-7:51 pm

2 stops23h 46m

$332

OntarioChicago

ONT - RFD

ONTRFD

Ontario

Wed 7/22

1:28 pm-12:24 pm

1 stop20h 56m

Chicago Greater Rockford

Sun 7/26

1:14 pm-7:53 pm

1 stop8h 39m

$392

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

Prices

Airlines

Layovers

Other information

What is the typical price of a round-trip flight between Ontario and Chicago?

What is the cheapest month to fly to Chicago?

The month of September is, on average, the cheapest month to fly to Chicago from Ontario, with most prices found around $102. If you’re not able to fly to Chicago in September, then April is your next best option. Flight prices from Ontario to Chicago during April average around $108.

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 Thursday when prices can be found for as low as $374. 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 $443.

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 $300. In contrast, the most expensive time of day to depart to Chicago is at noon when prices are around $485.

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 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 $425 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 $290 on momondo.

Can stopping save me money on Ontario to Chicago flights?

No. A direct flight is the cheapest option for a flight between Ontario to Chicago.

How have Ontario to Chicago flight prices changed over time?

As of May 2026, prices for Ontario to Chicago flights are approximately 98% more expensive when compared to flights at the same time last year.

When to book flights from Ontario to Chicago

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to Chicago according to our flight data. Find out which month and days have the cheapest flights.

Estimated round-trip price

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

Best Price Found	$210
Fastest flight time	3h 45m
Direct flights	Every day
Airports in Chicago	3 airports

The best one-way flight to Chicago from Ontario in the past 72 hours is $210. The best round-trip flight deal from Ontario to Chicago found on momondo in the last 72 hours is $411.

The fastest flight from Ontario to Chicago takes 3h 45m

Direct flights go from Ontario to Chicago every day.

There are 3 airports in Chicago. From Ontario there are direct flights to Chicago O'Hare Intl (ORD), Chicago Midway (MDW).

Search flight deals

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 May 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 MAX 8, making up 17.68% of the total bookings. Other popular models include Boeing 737-900 with 13.29%, Airbus A321neo with 10.97%, and Airbus A320-100/200 with 8.90%.
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 41% of the total bookings. Other popular airlines include Southwest with 31%, Frontier with 20%, and Delta with 4%.

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
Frontier	PriceFrom $117	Free Cancellation	Rating 5.6 2,953 reviews	Search Frontier flights
United Airlines	PriceFrom $226	Free Cancellation	Rating 7.4 9,711 reviews	Search United Airlines flights
Southwest	PriceFrom $258	Free Cancellation	Rating 8.0 4,299 reviews	Search Southwest flights
Delta	PriceFrom $260	Free Cancellation	Rating 7.9 8,452 reviews	Search Delta flights
American Airlines	PriceFrom $316	Free Cancellation	Rating 7.1 11,664 reviews	Search American Airlines flights

Southwest Flights From Ontario to Chicago
Southwest flight deals from Ontario to Chicago start from $258 round-trip. Over the 7 Southwest flights for this route in a normal week, average airfare is usually $434 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 $226, round-trip. It should be noted that an average United Airlines flight deal for this route in this time was higher, at $456 round-trip. United Airlines operates 4 flights out of Ontario into Chicago in an average week, so prices vary by time and availability. 9,711 United Airlines reviews by users on momondo have scored the airline at 7.4/10.

Merrillville

New Buffalo

Hammond

Saint Joseph

Benton Harbor

Portage

Lansing

Valparaiso

Munster

Schererville

Crown Point

Chesterton

Monticello

Porter

Griffith

Saint John

Why 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.

An easier way to manage your Chicago trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Start using Trips

Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

1 adult

Sat 6/13

Sat 6/20

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States

Nearby airports

Airlines

Cabin classes

Other United States destinations

Other flights from Ontario

Complete your trip

Feeling lucky

Fly into one of these airports located in Chicago

Chicago Midway Airport

Chicago O'Hare Intl Airport

Chicago Greater Rockford Airport

Cheap flights from Ontario to Chicago from $99

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 7/21. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

Find the cheapest flights from Ontario to Chicago

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

Cheap direct flights

Frontier flights from Ontario to Chicago

Our best Frontier deals on Ontario to Chicago flight tickets

United Airlines flights from Ontario to Chicago

Our best United Airlines deals on Ontario to Chicago flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from Ontario to Chicago that are best for you.

See travel insights to Chicago from

How to get the cheapest flight ticket from Ontario to Chicago

What is the typical price of a round-trip flight between Ontario and Chicago?

What is the cheapest month to fly to Chicago?

What is the cheapest day to depart on your flight to Chicago?

What is the cheapest time of day to depart on your flight to Chicago?

What is the cheapest Ontario to Chicago flight route?

How far in advance should I book a flight from Ontario to Chicago?

Can stopping save me money on Ontario to Chicago flights?

How have Ontario to Chicago flight prices changed over time?

What is the cheapest airline that flies from Ontario to Chicago?

What airlines fly to Chicago?

Which airport is the most popular layover for flights between Ontario and Chicago?

Which layover airport offers the lowest fares from Ontario to Chicago?

Which layover airport has the shortest travel time from Ontario to Chicago?

Which layover airport has the shortest connection time from Ontario to Chicago?

How many flights depart from Ontario to Chicago on average per day?

How many flights depart from Ontario to Chicago on average per week?

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

Best Price Found

Fastest flight time

Direct flights

Airports in Chicago

Frequently asked questions about flying from Ontario to Chicago

Best airlines flying from Ontario to Chicago

Compare and see reviews for airlines that fly from Ontario to Chicago with momondo

Southwest Flights From Ontario to Chicago

United Airlines Flights From Ontario to Chicago

Traveling to a place near Chicago?

Why use momondo?

An easier way to manage your Chicago trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to the United States

Fly into one of these airports located in Chicago

Airports listed have a maximum distance of 78.5 mi from Chicago

Fly your favorite airline to Chicago

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Cabin classes currently available on flights to Chicago

List of cabin classes available on flights landing in Chicago. Availability may vary depending on flight origin and airline.

Popular cities in the United States

Popular flights according to clicks in the last 7 days on momondo

Fly to other destinations from Ontario

According to popular flight searches on momondo this year

Complete your trip to Chicago

Explore popular destinations other users love

According to popular flight searches on momondo this year