ONT

$77 Find Cheap Flights from Illinois to Ontario

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 4/14. 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

Thu, Apr 23 - Wed, Apr 29
Frontier Logo
9:55 pm - 9:04 pm
STL
-
ONT
25h 09m
1 stop
Frontier Logo
12:59 am - 7:21 pm
ONT
-
STL
16h 22m
1 stop
$160Frontier
Thu, Apr 23 - Fri, Apr 24
Frontier Logo
9:55 pm - 9:04 pm
STL
-
ONT
25h 09m
1 stop
Frontier Logo
12:59 am - 7:32 pm
ONT
-
STL
16h 33m
1 stop
$162Frontier
Thu, May 7 - Sun, May 10
Multiple Airlines Logo
9:42 pm - 10:05 am
ORD
-
ONT
14h 23m
1 stop
Multiple Airlines Logo
8:06 pm - 10:46 am
ONT
-
ORD
12h 40m
2 stops
$311Multiple Airlines
Wed, Apr 15 - Sun, Apr 26
Multiple Airlines Logo
6:16 pm - 4:38 pm
ORD
-
ONT
24h 22m
1 stop
Multiple Airlines Logo
9:29 pm - 3:17 pm
ONT
-
ORD
39h 48m
2 stops
$319Multiple Airlines
Sat, Apr 25 - Sat, May 2
Southwest Logo
3:20 pm - 5:35 pm
MDW
-
ONT
4h 15mnonstop
Southwest Logo
11:55 pm - 5:40 am
ONT
-
MDW
3h 45mnonstop
$327Southwest
Tue, Apr 28 - Tue, May 5
Southwest Logo
11:00 am - 1:15 pm
MDW
-
ONT
4h 15mnonstop
Southwest Logo
11:55 pm - 5:40 am
ONT
-
MDW
3h 45mnonstop
$329Southwest
Sat, Aug 1 - Mon, Aug 10
Delta Logo
11:08 am - 6:23 pm
MLI
-
ONT
9h 15m
1 stop
Delta Logo
10:59 pm - 10:26 am
ONT
-
MLI
9h 27m
1 stop
$369Delta
Thu, May 28 - Sun, May 31
United Airlines Logo
2:31 pm - 10:37 pm
MLI
-
ONT
10h 06m
2 stops
United Airlines Logo
6:30 am - 5:52 pm
ONT
-
MLI
9h 22m
1 stop
$374United Airlines
Fri, Jun 12 - Thu, Jul 2
United Airlines Logo
3:52 pm - 10:46 pm
MLI
-
ONT
8h 54m
1 stop
United Airlines Logo
6:30 am - 5:52 pm
ONT
-
MLI
9h 22m
1 stop
$394United Airlines
Tue, Aug 4 - Mon, Aug 10
Delta Logo
11:08 am - 6:23 pm
MLI
-
ONT
9h 15m
1 stop
Delta Logo
10:59 pm - 10:26 am
ONT
-
MLI
9h 27m
1 stop
$424Delta
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$77
Best time to beat the crowds with an average 1% drop in price.
Most popular time to fly with an average 1% increase in price.
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)