$481 Find Cheap Flights from Sydney to Illinois

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Sydney to Illinois departing on 5/4. 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

KAYAK searches hundreds of travel sites at once for deals on flights to Illinois

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Sydney to Illinois, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Sydney to Illinois, as well as popular online travel agencies
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Sydney to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicago2 stops$960
St. Louis
St. Louis2 stops$1,087
Chicago
Chicago2 stops$960
St. Louis
St. Louis2 stops$1,087

Book Cheap Sydney to Illinois Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Sydney to Illinois 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 Sydney to Illinois

Mon, Mar 2 - Mon, Mar 9
Air New Zealand Logo
1:55 pm - 10:59 pm
SYD
-
ORD
26h 04m
2 stops
Air New Zealand Logo
4:00 pm - 8:45 am
ORD
-
SYD
24h 45m
2 stops
$960Air New Zealand
Mon, Feb 2 - Mon, Feb 16
Air Canada Logo
11:20 am - 10:05 pm
SYD
-
ORD
27h 45m
2 stops
Air Canada Logo
3:35 pm - 9:35 am
ORD
-
SYD
25h 00m
1 stop
$992Air Canada
Mon, Feb 2 - Mon, Feb 16
Air Canada Logo
11:20 am - 10:05 pm
SYD
-
ORD
27h 45m
2 stops
Air Canada Logo
12:50 pm - 9:35 am
ORD
-
SYD
27h 45m
2 stops
$995Air Canada
Mon, Feb 2 - Mon, Feb 16
Air Canada Logo
11:20 am - 2:41 pm
SYD
-
ORD
20h 21m
1 stop
Air Canada Logo
3:35 pm - 9:35 am
ORD
-
SYD
25h 00m
1 stop
$1,004Air Canada
Tue, Mar 3 - Mon, Apr 13
Multiple Airlines Logo
11:20 am - 3:29 pm
SYD
-
STL
45h 09m
2 stops
Multiple Airlines Logo
2:40 pm - 7:20 am
STL
-
SYD
25h 40m
2 stops
$1,102Multiple Airlines
Tue, Mar 3 - Tue, Mar 10
Multiple Airlines Logo
11:20 am - 3:29 pm
SYD
-
STL
45h 09m
2 stops
Multiple Airlines Logo
4:30 pm - 8:35 am
STL
-
SYD
24h 05m
2 stops
$1,105Multiple Airlines
Mon, Feb 2 - Mon, Feb 16
Delta Logo
10:40 am - 5:29 pm
SYD
-
MDW
23h 49m
2 stops
Delta Logo
1:26 pm - 8:30 am
MDW
-
SYD
26h 04m
2 stops
$1,159Delta
Tue, Mar 3 - Mon, Apr 13
American Airlines Logo
11:20 am - 7:29 pm
SYD
-
STL
25h 09m
2 stops
American Airlines Logo
6:20 am - 7:05 am
STL
-
SYD
33h 45m
1 stop
$1,160American Airlines
Wed, Jan 28 - Mon, Feb 9
American Airlines Logo
11:20 am - 11:59 pm
SYD
-
STL
29h 39m
1 stop
American Airlines Logo
7:04 am - 9:00 am
STL
-
SYD
32h 56m
1 stop
$1,161American Airlines
Sun, Mar 1 - Mon, Jun 1
Delta Logo
10:40 am - 5:45 pm
SYD
-
MDW
24h 05m
2 stops
Delta Logo
1:00 pm - 6:35 am
MDW
-
SYD
26h 35m
2 stops
$1,207Delta
Booking Insights

KAYAK's insights & trends for Sydney to Illinois flights

Get data-powered insights and trends into flights from Sydney to Illinois to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from Sydney to Illinois?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Sydney to Illinois departing in March.

What is the cheapest month to fly from Sydney to Illinois?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Sydney to Illinois, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Sydney to Illinois is March, when tickets cost $741 (return) on average. On the other hand, the most expensive months are December and November, when the average cost of round-trip tickets is $1,337 and $1,155 respectively.

How far in advance should I book a flight from Sydney to Illinois?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Sydney to Illinois, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Sydney to Illinois, you should book around 2 weeks before departure, which saves you about 24% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 18 weeks before departure.

Good to know

Low seasonMarch
Cheapest flight$481
Best time to beat the crowds with an average 16% drop in price.
Most popular time to fly with an average 7% increase in price.
Flight from Sydney to Chicago O'Hare Airport

FAQs - booking Illinois flights

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

    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 Sydney to Illinois.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Sydney to 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 Sydney to Illinois?

    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 from Sydney to Illinois with an airline and back with another airline.

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

    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 from Sydney to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airlines flying from Sydney to Illinois

 
See real verified KAYAK customer reviews for airlines flying from Sydney to Illinois. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Sydney to Illinois? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.5
Qantas AirwaysOverall score based on 972 reviews
8.2Crew
7.7Boarding
7.2Entertainment
7.0Food
7.5Comfort
Airline reviews

The crew were wonderful - if only the customers were as well behaved as the attendants!! Ha ha! If you could just talk to God and ask for less turbulence next time.... Juuuuust kidding....

10.0 ExcellentAnonymous, Jan 2026
SYD - SIN
Read more Qantas Airways reviews

The crew were wonderful - if only the customers were as well behaved as the attendants!! Ha ha! If you could just talk to God and ask for less turbulence next time.... Juuuuust kidding....

Basic airline, aircraft and service. AA gets you from point A to B. My flight was delayed by 2 hours too.

No internet on flight, which makes log travels really hard.

My flight from Dallas to Sydney was cancelled. My entire trip was rerouted to include the following: Hartford to Washington DC Washington DC to JFK JFK to Auckland Auckland to Christchurch I paid for an aisle seat on the flight to Auckland and was asked if I would take a window seat to accommodate a family. The agent at the podium failed to mention that the family had a 3 month old baby and that a bassinet would be used during the 16 hour flight. The only way I could get out of my seat was to crawl under the bassinet of the sleeping baby. I think it is wrong that I was no given the choice to sit in another seat, that the agent knew what she was doing and chose to not properly disclose my seating arrangement. Terrible treatment.

they ran out of fruit for breakfast and so I just had a yogurt instead. other than that the flight was good

by the time they got to our row, they were out of some of the food options. games and movies were great but maybe more game options like tetris or pac man would be great

Great as usual, some delays but well communicated and made up for in the air

Poor! This flight was delayed 14 hours. There was no assistance in helping customers find other routes to their destination, nor any other kind of support. It was a chaotic experience. I'm not likely to fly with AA going forward.

Business class points redemption - good value for points paid, dubious value if out of your own pocket, domestic class business product okay for this length of flight. The flight left and arrived on time, crew were good, aircraft was a bit old and tired, but still miles ahead of their competitors in Virgin and Jetstar.

We were upgraded and after just a short delay in attending to a safety check we were on our way. Would definately fly Qantas International on their Dreamliner again.

It was good but only meal served is very less. Meantime good to add rice and chicken in one of meal

Perfect flight. Smooth flight. Arrived 20 minutes early at destination. Excellent service.

The flights were on time which was great give. It was holiday travel season and there’d been some weather issues. The only complaint and this is every time with United is the terrible seat design. The head rest is not built for comfort and having my neck bent forward for a cross country trip reminded me while I try not to take United flights as a rule.

Everything was absolutely wonderful from check in to baggage claim. Staff was very professional and sweet. Will definitely recommend United to family and friends.

The staff was nice, however boarding taking 2 hours. That’s insane. Overall very bad experience, a lot of turbulence and when landed in Chicago was horrible. I don’t think I’ll flight with UA again.

An international flight on an apron is pretty unusual in my 40 years of traveling. Departure delay. Luggage despite over an hour connection did not make it to the flight. Actually still in Germany. My luggage was not moved until I reached my final destination despite knowing it to be left in Germany upon my arrival in Chicago. The service left me a little off, both going and returning from Europe. Light on in the cabin even during a night flight and lots of traffic no matter what. Maybe passengers want more service? As a frequent traveler i just want to be able to sleep, the food will be better at the destination anyway. So since the cabin crew woke me up I asked for a cocktail, I did not get the best response although sitting in row 20 premium economy. I usually fly premium economy or business and my 2 flight to Europe in 2025 with United both had luggage delays and other minor issues. American flights to Australia, Canada and Europe went smoothly and Premium plus feels very much like business light. Is United Club becoming a waste and Silver/Gold levels another waste??

They did the one thing that really matters - got to Chicago early.

The flight was on time. I generally don’t drink or eat on short flights and the seats were good and the flight attendants were friendly. That’s all I expect

It was nice to have gotten up upgraded to first class with a meal on a three hour flight

Very bad! They kept delaying my flight and wouldn’t do anything about it

Everything you need to know for your flight from Sydney to Illinois

Information on your arrival and departure airports