Ontario to Chicago flights
The cheapest round trip we found from Ontario to Chicago is $130 (Nov 6 – 13, 1 stop), 35% below the usual $200.
ONT to CHI · Round trip · Economy · Prices per person in USD · Price found (1 day ago)
Cheapest found
Cheapest round trip by month
Lowest fare found per departure month| Month | Cheapest round trip |
|---|---|
| November 2026 | $130 (cheapest month) |
| December 2026 | $139 |
| January 2027 | $190 |
| February 2027 | No fares found yet |
| March 2027 | $408 |
Cheapest dates in the next 4 months
Round trip, per person-
Nov 6 – 13 7 nights · leave Fri$130 −35% vs usual$130 −35% vs usual Book
Frontier Airlines 1 stop · 4h 53m -
Jan 15 – 22, 2027 7 nights · leave Fri$190 −5% vs usual$190 −5% vs usual Book
Frontier Airlines 1 stop · 4h 52m
-
Dec 10 – 14 4 nights · leave Thu$196$196 Book
Frontier Airlines 1 stop · 4h 53m
-
Nov 18 – 22 4 nights · leave Wed$236 +18% vs usual$236 +18% vs usual Book
Frontier Airlines 1 stop · 4h 47m
-
Nov 6 – 8 2 nights · leave Fri$242 +21% vs usual$242 +21% vs usual Book
Frontier Airlines 1 stop · 4h 53m
-
Nov 5 – 8 3 nights · leave Thu$267 +34% vs usual$267 +34% vs usual Book
Frontier Airlines 1 stop · 4h 47m
-
Dec 28 – Jan 4, 2027 7 nights · leave Mon$270 +35% vs usual$270 +35% vs usual Book
Southwest Airlines 1 stop · 3h 45m -
Nov 11 – 15 4 nights · leave Wed$313 +56% vs usual$313 +56% vs usual Book
Frontier Airlines 1 stop · 4h 47m
Prices change often. The booking site shows the final price before you pay. Other dates? Set an alert
Things to do in Chicago
One Go City pass for Shedd Aquarium, Skydeck Chicago, 360 CHICAGO and more
- All-Inclusive Pass Unlimited Visit as many attractions as you like for 1–5 days from $149 See pass
- Explorer Pass Pick 3–7 of 36 attractions from $109 See pass
- Essentials Pass A few top attractions, chosen as you go from $99 See pass
Go City prices checked Oct 23, 2026; the final price is on Go City. Partner links: we may earn a commission if you book, at no extra cost to you.
Plan the rest of your trip
Chicago · Nov 6 – 13Partner links: we may earn a commission if you book, at no extra cost to you.
Good to know
More from Ontario
-
-
-
-
-
-
-
-
Flights to Chicago from other cities
-
-
-
-
-
-
Ontario to Chicago: questions
How much does a flight from Ontario to Chicago cost?
The cheapest round trip we have found right now is $130, leaving November 6 and returning November 13. The usual price on this route is about $200, so this fare is 35% less. Prices are per person, economy, in USD.
What is the cheapest month to fly from Ontario to Chicago?
November 2026, with round trips from $130. The most expensive month in our data is March (from $408). Based on the 4 months ahead we have prices for.
Which airports do Ontario to Chicago flights use?
Ontario airports include Ontario International (ONT). Chicago airports include O'Hare International (ORD), Chicago Midway International (MDW) and Chicago Rockford International (RFD). The prices on this page cover every airport in both cities (ONT and CHI are the city codes).
About this route
We track round-trip economy fares from Ontario (United States) to Chicago (United States) using Travelpayouts / Aviasales data. The cheapest round trip we've found is $130, departing November 6 and returning November 13, about 35% below the usual $200. Right now we're following 8 upcoming date combinations on this route. The cheapest month to fly in our data is November, from $130. Prices are per person and were correct when found; the final price is set by the airline or booking site when you book.