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Ontario

$53+ Cheap flights from Illinois to Ontario (ONT)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 2/15. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — ONT
Dec 27 — Jan 31
Fri 12/27
Fri 1/3
1 adult, Economy
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Cheap flight deals from Illinois to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Illinois (USIL) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated December 22, 2024.

Round-trip from

$106
(Cheapflightsfares)

One-way from

$53
(Mytrip)
From Illinois to Ontario
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One-way flight from Illinois to Ontario
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Find flight deals from Illinois to Ontario

Cheapest flights from Illinois to Ontario
Explore the most affordable flight options available from Illinois to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 22, 2024.

This FlightHub deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/239:29 pmSTL - ONT
1 stop11h 40mFrontier
Sun 1/510:31 pmONT - STL
1 stop19h 58mFrontier
Deal found 12/21$324
This FlightHub deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/2510:27 pmMDW - ONT
1 stop15h 15mFrontier
Sat 1/113:52 pmONT - MDW
1 stop17h 56mFrontier
Deal found 12/21$330
This Gotogate deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/236:00 amORD - ONT
1 stop7h 00mFrontier
Tue 12/3112:59 amONT - ORD
1 stop20h 47mFrontier
Deal found 12/21$361
This Delta deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/224:59 pmMLI - ONT
1 stop8h 42mDelta
Thu 12/2611:56 amONT - MLI
1 stop8h 28mDelta
Deal found 12/21$488
This American Airlines deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/223:32 pmMLI - ONT
1 stop8h 56mAmerican Airlines
Thu 12/2610:02 amONT - MLI
2 stops9h 54mAmerican Airlines
Deal found 12/21$493
This Delta deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2212:40 pmORD - ONT
1 stop9h 01mDelta
Wed 12/251:05 pmONT - ORD
1 stop6h 34mDelta
Deal found 12/21$518
This Delta deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/235:03 pmMDW - ONT
1 stop8h 38mDelta
Thu 1/25:30 amONT - MDW
2 stops10h 14mDelta
Deal found 12/21$523
This Southwest deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/314:45 pmSTL - ONT
1 stop7h 25mSouthwest
Sun 1/53:45 pmONT - STL
1 stop6h 50mSouthwest
Deal found 12/21$532
This Southwest deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/312:55 pmMDW - ONT
2 stops9h 15mSouthwest
Tue 1/149:20 amONT - MDW
1 stop5h 30mSouthwest
Deal found 12/21$558
This Southwest deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/263:10 pmORD - ONT
2 stops7h 55mSouthwest
Sun 12/291:55 pmONT - ORD
1 stop6h 40mSouthwest
Deal found 12/21$568
This United Airlines deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/244:00 pmORD - ONT
1 stop6h 49mUnited Airlines
Sun 12/295:05 amONT - ORD
1 stop6h 10mUnited Airlines
Deal found 12/21$604
This American Airlines deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/235:30 amPIA - ONT
2 stops11h 55mAmerican Airlines
Fri 12/277:15 amONT - PIA
1 stop5h 53mAmerican Airlines
Deal found 12/21$623

Find flights from Illinois to Ontario within your budget

Customize your flight search to find flights from Illinois to Ontario that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated December 22, 2024.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Sat 2/8

7:09 pm-11:47 pm

1 stop6h 38m

Ontario

Fri 2/14

12:59 am-9:16 am

1 stop6h 17m

$106

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Tue 4/1

7:20 am-1:42 pm

1 stop8h 22m

Ontario

Wed 4/2

3:17 pm-12:42 am

1 stop7h 25m

$174

ChicagoOntario

MDW - ONT

MDWONT

Chicago Midway

Tue 4/1

6:40 am-2:27 pm

1 stop9h 47m

Ontario

Wed 4/2

3:17 pm-12:21 am

1 stop7h 04m

$174

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Tue 2/4

1:39 pm-11:43 am

1 stop24h 04m

Ontario

Tue 2/11

7:45 am-1:25 pm

1 stop27h 40m

$178

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Wed 1/29

2:07 pm-8:13 pm

1 stop8h 06m

Ontario

Mon 2/3

6:00 am-5:59 pm

1 stop9h 59m

$246

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Sat 1/25

11:47 am-7:31 pm

2 stops9h 44m

Ontario

Fri 2/21

11:59 pm-8:21 am

1 stop6h 22m

$251

ChicagoOntario

ORD - ONT

ORDONT

Chicago O'Hare Intl

Tue 1/21

7:20 pm-11:53 pm

1 stop6h 33m

Ontario

Sat 2/22

1:05 pm-11:48 pm

1 stop8h 43m

$256

ChicagoOntario

MDW - ONT

MDWONT

Chicago Midway

Sat 2/1

3:41 pm-10:52 pm

1 stop9h 11m

Ontario

Tue 2/4

1:00 pm-10:20 pm

1 stop7h 20m

$256

MolineOntario

MLI - ONT

MLIONT

Moline Quad-City

Thu 1/16

5:05 pm-10:52 pm

1 stop7h 47m

Ontario

Thu 1/23

1:00 pm-10:38 pm

1 stop7h 38m

$288

St. LouisOntario

STL - ONT

STLONT

Lambert-St Louis

Tue 5/6

7:00 am-3:12 pm

1 stop10h 12m

Ontario

Mon 5/12

11:30 am-11:56 pm

1 stop10h 26m

$328

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/20

Showing 1-10 of 42 results
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Best time to book a flight from Illinois to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Illinois with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Travel insights for flights from Illinois to Ontario

Get recent, data-driven insights about flights from Illinois to Ontario including ideal travel times, pricing trends, and more.

What is the cheapest month to book a flight from Illinois to Ontario?

Currently, August is the cheapest month in which you can book a flight from Illinois to Ontario (average of $246). Flying from Illinois to Ontario in March is currently the most expensive (average of $317). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IL to ONT?

Find hourly flight availability from Illinois to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 22, 2024.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Illinois to Ontario as you normally would.

Rainfall in Ontario by month

Plan your trip to Ontario by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

Plan your trip to Ontario by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated December 22, 2024.
Get a feel of what it's like to fly with United Airlines, American Airlines and Alaska Airlines from Illinois to Ontario by reading reviews from past customers. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,804 reviews

Boarding

8.2

Entertainment

7.7

Comfort

8.1

Crew

8.7

Food

7.2

Overall

8.1

Reviews

1 / 10

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Southwest
8.1
Very good
4,804 reviews
Southwest
8.1
Very good
4,804 reviews

Boarding

8.2

Entertainment

7.7

Comfort

8.1

Crew

8.7

Food

7.2

Overall

8.1

Reviews

1 / 10

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Alaska Airlines
8.0
Very good
9,537 reviews
Southwest
8.1
Very good
4,804 reviews

Boarding

8.2

Entertainment

7.7

Comfort

8.1

Crew

8.7

Food

7.2

Overall

8.1

Reviews

1 / 10

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Delta
8.0
Very good
8,594 reviews
Southwest
8.1
Very good
4,804 reviews

Boarding

8.2

Entertainment

7.7

Comfort

8.1

Crew

8.7

Food

7.2

Overall

8.1

Reviews

1 / 10

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

United Airlines
7.4
Good
9,028 reviews
Southwest
8.1
Very good
4,804 reviews

Boarding

8.2

Entertainment

7.7

Comfort

8.1

Crew

8.7

Food

7.2

Overall

8.1

Reviews

1 / 10

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,804 reviews

Boarding

8.2

Entertainment

7.7

Comfort

8.1

Crew

8.7

Food

7.2

Overall

8.1

Reviews

1 / 10

Flight was delayed by one hour and 40 minutes. Also baggage was delivered late at Boston. This delay made me miss my connection from Boston to Hyderabad

Related info for your journey

Find useful and relevant information for your journey from Illinois to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Ontario from Illinois?

    Located just 3.1 mi from the city center, Ontario (ONT) is the airport most travelers will use when flying to Ontario from Illinois.

  • What are the cheapest airlines to fly from Illinois to Ontario one-way?

    $53 is the cheapest one-way deal found within the past few days, from Frontier. You may also be able to find cheap deals on United Airlines and Delta, with prices starting from $123 and $128, respectively.

  • What are the most popular routes from Illinois to Ontario?

    When deciding which route to take from Illinois to Ontario consider Chicago O'Hare Intl - Ontario, Chicago Midway - Ontario or Lambert-St Louis - Ontario as they are the most popular.

  • Can I find deals for flights from Illinois to Ontario that include hotel bookings?

    Yes. In addition to deals on Illinois to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to Ontario?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to Ontario.

  • Can I find deals for business class flights from Illinois to Ontario?

    Yes. Cheapflights offers flight deals from Illinois to Ontario by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Illinois to Ontario?

    Currently, August is the cheapest month in which you can book a flight from Illinois to Ontario (average of $246). Flying from Illinois to Ontario in March is currently the most expensive (average of $317). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Alternative routes for Illinois to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Top 6 airlines flying from Illinois to Ontario

Discover the top 6 airlines that operate flights from Illinois to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated December 22, 2024.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$121Average$202FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$122Average$294FlexibilityNo cancel feeOn-time65%
American AirlinesCheapest$204Average$573FlexibilityNo cancel feeOn-time71%
DeltaCheapest$256Average$425FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$256Average$500FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$353Average$541FlexibilityNo cancel feeOn-time69%
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