$610 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 3/18. 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
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Cheap Flights from Sydney to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicago2 stops$1,020
St. Louis
St. Louis1 stop$1,029
Chicago
Chicago2 stops$1,020
St. Louis
St. Louis1 stop$1,029

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

Thu, Apr 16 - Thu, Apr 23
Multiple Airlines Logo
1:15 pm - 11:27 pm
SYD
-
ORD
25h 12m
2 stops
Multiple Airlines Logo
2:00 pm - 11:50 am
ORD
-
SYD
30h 50m
2 stops
$1,020Multiple Airlines
Tue, Apr 14 - Tue, Apr 21
Qantas Airways Logo
9:10 am - 11:57 pm
SYD
-
STL
29h 47m
1 stop
Qantas Airways Logo
6:21 am - 7:05 am
STL
-
SYD
33h 44m
1 stop
$1,029Qantas Airways
Thu, Mar 12 - Mon, Mar 16
American Airlines Logo
11:20 am - 5:53 pm
SYD
-
STL
22h 33m
2 stops
American Airlines Logo
6:38 am - 9:00 am
STL
-
SYD
34h 22m
1 stop
$1,065American Airlines
Tue, Apr 14 - Tue, Apr 21
American Airlines Logo
9:10 am - 11:57 pm
SYD
-
STL
29h 47m
1 stop
American Airlines Logo
3:38 pm - 7:05 am
STL
-
SYD
24h 27m
2 stops
$1,066American Airlines
Thu, Aug 6 - Sun, Aug 30
American Airlines Logo
12:00 pm - 4:51 pm
SYD
-
STL
19h 51m
1 stop
American Airlines Logo
3:33 pm - 7:05 am
STL
-
SYD
24h 32m
2 stops
$1,073American Airlines
Mon, Apr 13 - Mon, Apr 20
American Airlines Logo
12:00 pm - 10:59 pm
SYD
-
STL
25h 59m
1 stop
American Airlines Logo
6:21 am - 7:05 am
STL
-
SYD
33h 44m
1 stop
$1,079American Airlines
Thu, Aug 6 - Sun, Aug 30
United Airlines Logo
10:20 am - 8:43 pm
SYD
-
STL
25h 23m
2 stops
United Airlines Logo
11:25 am - 6:55 am
STL
-
SYD
28h 30m
2 stops
$1,083United Airlines
Thu, Mar 12 - Wed, Mar 25
Air Canada Logo
10:25 am - 2:41 pm
SYD
-
ORD
20h 16m
1 stop
Air Canada Logo
3:35 pm - 8:35 am
ORD
-
SYD
25h 00m
1 stop
$1,139Air Canada
Thu, Mar 12 - Wed, Mar 25
Air Canada Logo
10:25 am - 2:41 pm
SYD
-
ORD
20h 16m
1 stop
Air Canada Logo
7:25 am - 8:35 am
ORD
-
SYD
33h 10m
2 stops
$1,143Air Canada
Tue, Jul 14 - Tue, Sep 15
ANA Logo
11:50 am - 4:51 am
SYD
-
ORD
32h 01m
2 stops
ANA Logo
5:45 pm - 9:25 am
ORD
-
SYD
24h 40m
1 stop
$1,170ANA
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 April.

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 April, when tickets cost $849 (return) on average. On the other hand, the most expensive months are December and January, when the average cost of round-trip tickets is $1,337 and $1,159 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 4 weeks before departure, which saves you about 21% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 24 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$610
Best time to beat the crowds but there is an average 3% increase in price.
Most popular time to fly with an average 12% increase in price.
Flight from Sydney to St. Louis

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 1000 reviews
8.1Crew
7.4Comfort
7.2Entertainment
7.0Food
7.7Boarding
Airline reviews

When I originally booked this flight, I was expecting to travel on Qantas. When the itinerary changed and the long-haul segment was operated by American Airlines, we were disappointed but remained open-minded. Unfortunately, the overall service experience fell far short of expectations. This was a long-haul international flight. Getting up periodically to use the restroom or stretch is inevitable, especially on flights of this duration. However, each time we stood up, we felt as though we were inconveniencing the crew. The tone and body language often suggested that we were in the way or disrupting something simply by moving about the cabin. As a result, I avoided getting up as often as I needed to and was physically very sore upon arrival. Meal service was similarly impersonal. The options were presented in single words “beef or veggie,” “pasta or beef” without any description of what was actually being served. There was little engagement or courtesy beyond that. Even simple expressions of gratitude were often not acknowledged. I am accustomed to no-frills travel and do not expect luxury. What was disappointing was not the absence of extras, but the absence of basic warmth and professionalism. On a long-haul international flight, small moments of courtesy and humanity make a significant difference. In this case, the experience felt transactional and dismissive rather than welcoming. I hope this feedback is taken constructively, as there is a meaningful difference between efficient service and indifferent service.

4.0 OkayDesiree, Feb 2026
SYD - LAX
Read more Qantas Airways reviews

When I originally booked this flight, I was expecting to travel on Qantas. When the itinerary changed and the long-haul segment was operated by American Airlines, we were disappointed but remained open-minded. Unfortunately, the overall service experience fell far short of expectations. This was a long-haul international flight. Getting up periodically to use the restroom or stretch is inevitable, especially on flights of this duration. However, each time we stood up, we felt as though we were inconveniencing the crew. The tone and body language often suggested that we were in the way or disrupting something simply by moving about the cabin. As a result, I avoided getting up as often as I needed to and was physically very sore upon arrival. Meal service was similarly impersonal. The options were presented in single words “beef or veggie,” “pasta or beef” without any description of what was actually being served. There was little engagement or courtesy beyond that. Even simple expressions of gratitude were often not acknowledged. I am accustomed to no-frills travel and do not expect luxury. What was disappointing was not the absence of extras, but the absence of basic warmth and professionalism. On a long-haul international flight, small moments of courtesy and humanity make a significant difference. In this case, the experience felt transactional and dismissive rather than welcoming. I hope this feedback is taken constructively, as there is a meaningful difference between efficient service and indifferent service.

Flight arrived late with no one to help over 30 people rebook. I slept at the airport.

Business seats not as comfortable or private as most competitors (e.g. Qantas was outstanding), and movie selection was much more limited than Qantas or United has been recently

Hard to move and get out of my seat when the passenger in front is in recline position.

It was a good flight and no complaints. It just wasn't anything that was better than any other flight.

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

They never clean the toilet, and the food is worse

Wonderful. Quick boarding. Early departure and we arrived 30 minutes early at our destination. Unfortunately, when you arrive early, there is still a departing aircraft at our gate. We had to park for 30 minutes until the gate was clear. So our early arrival was not really early at the gate. Otherwise it was a quick and smooth flight. Appreciated the efficiency.

Chargers didn’t work, no entertainment and we had to wait for taxiing for easily 40 minutes after arriving early. Bags were late too!

No real complaints. The in flight food was much better than I expected. The in flight entertainment was excellent.

Crew was great (professional, attentive, prompt). Snacks for 4 hrs flight is deplorable.

Horrible Flight significantly delayed. Not due to united issue. But trying to rebook connection flight and get information about overnight accommodation was difficult. Agent did not seem to care or have any interest to help.

United Airlines is my preferred airlines and I am thankful for Gary who also help support me on the phone to switch my flight literally last min.

This Japanese airline provides great service and very helpful in assisting their passengers.

Seated dude next to me even though lots of empty rows. But main thing was we sat on the tarmac after landing for 30 minutes because of, in the words of the dude who sat next to me, “operational incompetence”. We got changing directions about where to pick up gate checked bags. Pilot and flight attendant were awesome though.

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

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

Information on your arrival and departure airports