ONT

$108 Find Cheap Flights from Illinois to Ontario - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight to Ontario departing on 8/25. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Flight Deals

Cheap Flights from Illinois to Ontario

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Illinois to Ontario that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Illinois to Ontario

Tue, Jul 14 - Tue, Jul 21
Frontier Logo
9:57 pm - 10:04 am
ORD
-
ONT
14h 07m
1 stop
Frontier Logo
6:00 am - 8:52 pm
ONT
-
ORD
12h 52m
1 stop
$218Frontier
Wed, Aug 19 - Tue, Aug 25
Frontier Logo
2:41 pm - 11:55 pm
ORD
-
ONT
11h 14m
1 stop
Frontier Logo
7:56 pm - 1:36 pm
ONT
-
ORD
15h 40m
1 stop
$220Frontier
Wed, Aug 19 - Tue, Aug 25
United Airlines Logo
8:06 pm - 10:35 pm
ORD
-
ONT
4h 29mnonstop
United Airlines Logo
7:00 am - 1:10 pm
ONT
-
ORD
4h 10mnonstop
$239United Airlines
Sat, Aug 15 - Sat, Aug 22
Southwest Logo
6:00 pm - 8:10 pm
MDW
-
ONT
4h 10mnonstop
Southwest Logo
11:55 pm - 5:45 am
ONT
-
MDW
3h 50mnonstop
$239Southwest
Sat, Aug 15 - Sat, Aug 22
Southwest Logo
6:00 pm - 8:10 pm
MDW
-
ONT
4h 10mnonstop
Southwest Logo
9:25 am - 6:25 pm
ONT
-
MDW
7h 00m
1 stop
$249Southwest
Fri, Nov 13 - Sat, Nov 14
Delta Logo
11:00 am - 6:18 pm
MLI
-
ONT
9h 18m
1 stop
Delta Logo
7:00 am - 4:22 pm
ONT
-
MLI
7h 22m
1 stop
$340Delta
Thu, Aug 20 - Fri, Aug 28
Delta Logo
4:24 pm - 9:52 pm
BMI
-
ONT
7h 28m
1 stop
Delta Logo
12:00 pm - 11:16 pm
ONT
-
BMI
9h 16m
1 stop
$349Delta
Tue, Jul 28 - Sat, Aug 1
American Airlines Logo
4:43 pm - 11:59 pm
PIA
-
ONT
9h 16m
1 stop
American Airlines Logo
5:34 am - 3:52 pm
ONT
-
PIA
8h 18m
1 stop
$379American Airlines
Fri, Jul 10 - Sun, Jul 12
American Airlines Logo
4:45 pm - 11:59 pm
MLI
-
ONT
9h 14m
1 stop
American Airlines Logo
11:59 pm - 10:39 am
ONT
-
MLI
8h 40m
1 stop
$419American Airlines
Sat, Nov 14 - Tue, Nov 17
United Airlines Logo
9:45 am - 8:56 pm
BMI
-
ONT
13h 11m
2 stops
United Airlines Logo
6:46 am - 4:38 pm
ONT
-
BMI
7h 52m
1 stop
$454United Airlines
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Good to know

Low seasonJanuary
Cheapest flight$108
Best time to beat the crowds with an average 3% drop in price.
Most popular time to fly and prices are also 4% lower on average.
Flight from Chicago O'Hare Airport to Ontario

FAQs for booking flights from Illinois to Ontario

  • How does KAYAK find such low prices on flights from Illinois to Ontario?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Illinois to Ontario.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to Ontario?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario from Illinois is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Illinois to Ontario?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Ontario with an airline and back to Illinois with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Illinois to Ontario?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Ontario from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Everything you need to know for your flight to Ontario

Information on the airport you'll fly into in Ontario

Ontario (ONT)