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

16 flights are operational weekly from Illinois to Ontario as of November 2025. The most popular departure day for this route is Mon, with 25% of flights per week taking off on this day.

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

Frontier, Alaska Airlines, and Delta are the most popular carriers operating from Illinois to Ontario

How long does it take to fly to Ontario?

Average flight duration from Illinois to Ontario depends on which airport you fly into and out of. Flying from Chicago to Los Angeles is 4h 20m on average, while flying from Peoria to Los Angeles is 6h 59m on average. Los Angeles is the most popular airport in Ontario.

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

As of November 2025, 2 flights take off from Illinois and land in Ontario each day. The most common flight departure time for this route is 7:00PM, with 53% of daily flights taking off in the evening.

What airlines fly to Ontario?

American Airlines, Spirit Airlines and United Airlines are the top three most popular airlines that fly to Ontario from Illinois according to our data. American Airlines is the first choice among our users, with 44% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 8 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.

When did momondo last update prices for flights from Illinois to Ontario Airport?

Prices for flights from Illinois to Ontario Airport refresh daily.

How many operators does momondo search for flights from Illinois to Ontario Airport?

As of November 2025, there are 5 operators available to choose from for flights from Illinois to Ontario Airport.

How old do you have to be to fly from Illinois to Ontario Airport?

The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Illinois 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.

$62 Cheap Flights from Illinois to Ontario in 2025/26

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Cheap round-trip flights

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7:43 pm - 11:59 pmSTL-ONT

6h 16m1 stop

6:00 am - 4:24 pmONT-STL

8h 24m1 stop

$158Frontier

Find Deal

Sat, Dec 20 - Thu, Dec 25

3:43 pm - 10:59 pmSTL-ONT

9h 16m1 stop

7:15 am - 2:46 pmONT-STL

5h 31m1 stop

$160Frontier

Find Deal

Wed, Jan 14 - Wed, Jan 21

8:36 am - 9:17 pmORD-ONT

38h 41m2 stops

2:59 pm - 8:09 pmONT-ORD

27h 10m1 stop

$200Multiple Airlines

Find Deal

Mon, Dec 8 - Mon, Dec 15

9:06 pm - 9:17 pmORD-ONT

26h 11m2 stops

6:45 am - 12:12 amONT-ORD

15h 27m1 stop

$201Multiple Airlines

Find Deal

Sun, Dec 14 - Thu, Dec 18

3:58 pm - 10:48 pmMLI-ONT

8h 50m1 stop

6:00 am - 3:27 pmONT-MLI

7h 27m1 stop

$289American Airlines

Find Deal

Sat, Jan 17 - Sat, Jan 24

7:31 am - 4:05 pmMLI-ONT

10h 34m2 stops

6:00 am - 3:27 pmONT-MLI

7h 27m1 stop

$294American Airlines

Find Deal

Sat, Jan 17 - Sat, Jan 24

5:51 am - 11:31 amMLI-ONT

7h 40m1 stop

12:41 pm - 10:28 pmONT-MLI

7h 47m1 stop

$314Delta

Find Deal

Sat, Feb 7 - Tue, Feb 10

5:51 am - 11:31 amMLI-ONT

7h 40m1 stop

12:41 pm - 10:28 pmONT-MLI

7h 47m1 stop

$324Delta

Find Deal

Sat, Feb 7 - Tue, Feb 10

8:40 am - 12:32 pmPIA-ONT

5h 52m1 stop

1:34 pm - 8:56 pmONT-PIA

5h 22m1 stop

$359United Airlines

Find Deal

Thu, Dec 4 - Sat, Dec 6

8:40 am - 5:37 pmPIA-ONT

10h 57m2 stops

1:34 pm - 8:56 pmONT-PIA

5h 22m1 stop

$364United Airlines

Find Deal

Thu, Dec 4 - Sat, Dec 6

Frontier flights from Illinois to Ontario

Our best Frontier deals on Illinois to Ontario flight tickets

Frontier

Dec 20

STL7:43 pmLambert-St Louis

6h 16m

1 stop

ONT11:59 pmOntario

Dec 25

ONT6:00 amOntario

8h 24m

1 stop

STL4:24 pmLambert-St Louis

$158

Find similar

Frontier

Jan 14

STL3:43 pmLambert-St Louis

9h 16m

1 stop

ONT10:59 pmOntario

Jan 21

ONT7:15 amOntario

5h 31m

1 stop

STL2:46 pmLambert-St Louis

$160

Find similar

Frontier

Jan 12

ORD10:37 pmChicago O'Hare Intl

21h 17m

1 stop

ONT5:54 pmOntario

Jan 18

ONT7:56 pmOntario

24h 48m

2 stops

ORD10:44 pmChicago O'Hare Intl

$162

Find similar

American Airlines flights from Illinois to Ontario

Our best American Airlines deals on Illinois to Ontario flight tickets

American Airlines

Jan 17

MLI3:58 pmMoline Quad-City

8h 50m

1 stop

ONT10:48 pmOntario

Jan 24

ONT6:00 amOntario

7h 27m

1 stop

MLI3:27 pmMoline Quad-City

$289

Find similar

American Airlines

Jan 17

MLI3:58 pmMoline Quad-City

8h 50m

1 stop

ONT10:48 pmOntario

Jan 24

ONT9:59 amOntario

9h 59m

2 stops

MLI9:58 pmMoline Quad-City

$294

Find similar

American Airlines

Jan 17

MLI7:31 amMoline Quad-City

10h 34m

2 stops

ONT4:05 pmOntario

Jan 24

ONT9:59 amOntario

9h 59m

2 stops

MLI9:58 pmMoline Quad-City

$299

Find similar

Fly from

Fly to

Route

Depart

Return

Price

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 12/20

7:43 pm-11:59 pm

1 stop6h 16m

Ontario

Thu 12/25

6:00 am-4:24 pm

1 stop8h 24m

$158

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Wed 1/14

3:43 pm-10:59 pm

1 stop9h 16m

Ontario

Wed 1/21

7:15 am-2:46 pm

1 stop5h 31m

$160

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Mon 12/8

8:36 am-9:17 pm

2 stops38h 41m

Ontario

Mon 12/15

2:59 pm-8:09 pm

1 stop27h 10m

$200

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Sun 12/14

9:06 pm-9:17 pm

2 stops26h 11m

Ontario

Thu 12/18

6:45 am-12:12 am

1 stop15h 27m

$201

MolineOntario

MLI - ONT

MLIONT

Moline Quad-City

Sat 1/17

3:58 pm-10:48 pm

1 stop8h 50m

Ontario

Sat 1/24

6:00 am-3:27 pm

1 stop7h 27m

$289

MolineOntario

MLI - ONT

MLIONT

Moline Quad-City

Sat 1/17

7:31 am-4:05 pm

2 stops10h 34m

Ontario

Sat 1/24

6:00 am-3:27 pm

1 stop7h 27m

$294

MolineOntario

MLI - ONT

MLIONT

Moline Quad-City

Sat 2/7

5:51 am-11:31 am

1 stop7h 40m

Ontario

Tue 2/10

12:41 pm-10:28 pm

1 stop7h 47m

$314

MolineOntario

MLI - ONT

MLIONT

Moline Quad-City

Sat 2/7

5:51 am-11:31 am

1 stop7h 40m

Ontario

Tue 2/10

12:41 pm-10:28 pm

1 stop7h 47m

$324

PeoriaOntario

PIA - ONT

PIAONT

Greater Peoria

Thu 12/4

8:40 am-12:32 pm

1 stop5h 52m

Ontario

Sat 12/6

1:34 pm-8:56 pm

1 stop5h 22m

$359

PeoriaOntario

PIA - ONT

PIAONT

Greater Peoria

Thu 12/4

8:40 am-5:37 pm

2 stops10h 57m

Ontario

Sat 12/6

1:34 pm-8:56 pm

1 stop5h 22m

$364

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How to get the cheapest flight ticket from Illinois 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

Prices

Airlines

Other information

What is the cheapest month to fly to Ontario?

In general, October is the cheapest month to fly from Illinois to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $245. If you aren’t able to travel during the month of October, then book flights to Ontario from Illinois during February instead. Flights to Ontario in February, while not as cheap as those in October, still average around $263.

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 Saturday, the most expensive travel day of the week, you can expect to see flight prices from Illinois to Ontario for around $487.

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 Illinois to Ontario when you can find flight prices for as low as $383. 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 morning when prices are $495 on average. Flights to Ontario from Illinois in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.

What is the cheapest Illinois to Ontario flight route?

Fly from Chicago Midway to Ontario for the best Illinois - 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 Illinois when booking weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $370 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from Illinois for as low as $281 on momondo.

What cabin class options are available on Illinois to Ontario flights?

There are 4 cabin classes available to choose from on Illinois 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 Illinois to Ontario flights?

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

Cheap Illinois to Ontario flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Illinois to Ontario

Best Price Found	$170
Fastest flight time	4h 15m
Direct flights	Every day
Airports in Ontario	1 airport

The best one-way flight to Ontario from Illinois in the past 72 hours is $170. The best round-trip flight deal from Illinois to Ontario found on momondo in the last 72 hours is $451.

The fastest flight from Illinois to Ontario takes 4h 15m

Direct flights go from Illinois to Ontario every day.

There is 1 airport near Ontario: Ontario (ONT)

Search flight deals

When did momondo last update prices for flights from Illinois to Ontario Airport?
Prices for flights from Illinois to Ontario Airport refresh daily.
How many operators does momondo search for flights from Illinois to Ontario Airport?
As of November 2025, there are 5 operators available to choose from for flights from Illinois to Ontario Airport.
How old do you have to be to fly from Illinois to Ontario Airport?
The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Illinois 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 Illinois to Ontario?
momondo data reveals that the most frequently booked plane model on the route from Illinois to Ontario is Boeing 737-800, representing 28.00% of all bookings. The subsequent popular models are Boeing 737 MAX 8 at 15.00%, Airbus A320neo at 9.00%, and Boeing 737-800 Passenger/BBJ2 (winglets) at 8.00%.

Best airlines flying from Illinois to Ontario

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

Airline	Rating	Free Cancellation	Price
Frontier	PriceFrom $125	Free Cancellation	Rating 5.8 3,103 reviews	Search Frontier flights
American Airlines	PriceFrom $231	Free Cancellation	Rating 7.2 11,048 reviews	Search American Airlines flights
United Airlines	PriceFrom $237	Free Cancellation	Rating 7.4 9,035 reviews	Search United Airlines flights
Delta	PriceFrom $256	Free Cancellation	Rating 7.9 8,002 reviews	Search Delta flights
Southwest	PriceFrom $282	Free Cancellation	Rating 8.0 4,252 reviews	Search Southwest flights

Why use momondo?

Why should I use momondo to find a flight deal from Illinois to Ontario?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Illinois to Ontario. momondo saves you time and could save you money on your trip.

Can I find flights from Illinois to Ontario with flexible booking policies on momondo?

All flight searches from Illinois to Ontario on momondo can be filtered to show those which offer flexible booking policies.

How can momondo help me find flights from Illinois to Ontario?

Once all potential Illinois to Ontario flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

I’m not ready to book a flight from Illinois to Ontario right now. Can momondo alert me if prices change?

Price alerts on flights to Ontario from Illinois are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

An easier way to manage your Ontario 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.

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Cheap flights from Illinois to Los Angeles from $62

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Illinois to Los Angeles departing on 1/23. 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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Our best American Airlines deals on Illinois to Ontario flight tickets

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How to get the cheapest flight ticket from Illinois 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 cheapest month to fly to Ontario?

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

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

What is the cheapest Illinois to Ontario flight route?

Fly from Chicago Midway to Ontario for the best Illinois - Ontario flight prices

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

What cabin class options are available on Illinois to Ontario flights?

There are 4 cabin classes available to choose from on Illinois 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 Illinois to Ontario flights?

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

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

Frontier, Alaska Airlines, and Delta are the most popular carriers operating from Illinois to Ontario

What airlines fly to Ontario?

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

As of November 2025, 2 flights take off from Illinois and land in Ontario each day. The most common flight departure time for this route is 7:00PM, with 53% of daily flights taking off in the evening.

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

16 flights are operational weekly from Illinois to Ontario as of November 2025. The most popular departure day for this route is Mon, with 25% of flights per week taking off on this day.

How long does it take to fly to Ontario?

Average flight duration from Illinois to Ontario depends on which airport you fly into and out of. Flying from Chicago to Los Angeles is 4h 20m on average, while flying from Peoria to Los Angeles is 6h 59m on average. Los Angeles is the most popular airport in Ontario.

Cheap Illinois to Ontario flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Illinois to Ontario

Best Price Found

Fastest flight time

Direct flights

Airports in Ontario

When did momondo last update prices for flights from Illinois to Ontario Airport?

How many operators does momondo search for flights from Illinois to Ontario Airport?

How old do you have to be to fly from Illinois to Ontario Airport?

What documentation or ID do you need to fly to Ontario Airport?

What is the most popular plane model from Illinois to Ontario?

Best airlines flying from Illinois to Ontario

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

Why use momondo?

Why should I use momondo to find a flight deal from Illinois to Ontario?

Can I find flights from Illinois to Ontario with flexible booking policies on momondo?

How can momondo help me find flights from Illinois to Ontario?

I’m not ready to book a flight from Illinois to Ontario right now. Can momondo alert me if prices change?

An easier way to manage your Ontario 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

Airports servicing California