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$454+ Cheap flights from Illinois to Sydney (SYD)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 5/16. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SYD
Mar 27 — Apr 31
Fri 3/27
Fri 4/3
1 adult, Economy
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Cheap flight deals from Illinois to Sydney

Cheapest flights from Illinois to Sydney
Explore the most affordable flight options available from Illinois to Sydney. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 25, 2026.

This Air Canada deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/274:15 pm
STL
-
SYD
2 stops48h 20m
Air Canada
Tue 11/311:20 am
SYD
-
STL
2 stops45h 10m
Air Canada
Deal found 2/20$1,011
This BusinessClass deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure BusinessClass is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/274:15 pm
STL
-
SYD
1 stop48h 20m
Multiple Airlines
Tue 11/311:20 am
SYD
-
STL
1 stop45h 10m
Multiple Airlines
Deal found 2/20$1,024
This Trip.com deal was found by Cheapflights users on 2/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/112:44 pm
ORD
-
SYD
2 stops32h 21m
Multiple Airlines
Mon 6/156:00 am
SYD
-
ORD
2 stops38h 23m
Multiple Airlines
Deal found 2/22$1,072
This Kiwi.com deal was found by Cheapflights users on 2/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:20 am
ORD
-
SYD
2 stops38h 30m
Multiple Airlines
Tue 5/125:50 pm
SYD
-
ORD
1 stop27h 00m
Multiple Airlines
Deal found 2/24$1,082
This Kiwi.com deal was found by Cheapflights users on 2/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:20 am
ORD
-
SYD
2 stops38h 30m
Multiple Airlines
Mon 5/115:50 pm
SYD
-
ORD
1 stop27h 00m
Multiple Airlines
Deal found 2/24$1,083
This Kiwi.com deal was found by Cheapflights users on 2/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:20 am
ORD
-
SYD
2 stops38h 30m
Multiple Airlines
Thu 5/145:50 pm
SYD
-
ORD
1 stop27h 00m
Multiple Airlines
Deal found 2/24$1,089
This Kiwi.com deal was found by Cheapflights users on 2/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:20 am
ORD
-
SYD
2 stops38h 30m
Multiple Airlines
Sat 5/165:50 pm
SYD
-
ORD
1 stop27h 00m
Multiple Airlines
Deal found 2/24$1,090
This Kiwi.com deal was found by Cheapflights users on 2/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:20 am
ORD
-
SYD
2 stops38h 30m
Multiple Airlines
Sun 5/105:50 pm
SYD
-
ORD
1 stop27h 00m
Multiple Airlines
Deal found 2/24$1,094
This oojo deal was found by Cheapflights users on 2/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/186:30 am
STL
-
SYD
2 stops43h 40m
Qantas Airways
Wed 10/71:00 pm
SYD
-
STL
1 stop21h 25m
Qantas Airways
Deal found 2/24$1,096
This oojo deal was found by Cheapflights users on 2/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/46:21 am
STL
-
SYD
2 stops38h 34m
Qantas Airways
Mon 5/1812:00 pm
SYD
-
STL
1 stop22h 30m
Qantas Airways
Deal found 2/24$1,097
This lastminute.com deal was found by Cheapflights users on 2/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure lastminute.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/96:21 am
STL
-
SYD
2 stops35h 59m
Qantas Airways
Thu 4/1612:00 pm
SYD
-
STL
1 stop20h 21m
Qantas Airways
Deal found 2/23$1,098
This oojo deal was found by Cheapflights users on 2/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/244:13 pm
STL
-
SYD
1 stop21h 42m
Qantas Airways
Tue 3/35:00 pm
SYD
-
STL
2 stops23h 59m
Qantas Airways
Deal found 2/21$1,102

Find flight deals from Illinois to Sydney

Keep the following information in mind while searching for Illinois to Sydney flight deals. Data was last updated February 25, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$1,072
(Trip.com)

One-way from

$454
(Kiwi.com)

Popular in

December

Cheapest in

October

Average price

$1,097
Provider with most accurate pricing for Chicago (CHI)-Sydney Kingsford Smith flight deals.
Search Deals
Provider most trusted by Cheapflights users for Chicago (CHI)-Sydney Kingsford Smith flights.
Search Deals
From Illinois to Sydney Kingsford Smith
Search Deals
One-way flight from Illinois to Sydney Kingsford Smith
Search Deals
Highest demand for flights based on searches. 9% potential increase in price ($139 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($23 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Illinois to Sydney that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 25, 2026.
Use the filters below to find and compare flights from Illinois to Sydney that are best for you.

Fly from

Illinois

Fly to

Sydney

Route

Depart

Return

Price

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 5/4

9:59 am-6:50 am

2 stops29h 51m

Sydney Kingsford Smith

Mon 5/18

9:15 am-5:56 pm

2 stops23h 41m

$1,149

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 3/18

7:03 am-7:25 am

2 stops32h 22m

Sydney Kingsford Smith

Wed 3/25

9:40 am-5:07 pm

2 stops23h 27m

$1,149

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 4/7

12:04 pm-6:50 am

2 stops27h 46m

Sydney Kingsford Smith

Tue 4/14

9:15 am-9:19 pm

2 stops27h 04m

$1,149

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 3/15

10:50 am-7:25 am

2 stops28h 35m

Sydney Kingsford Smith

Sat 3/21

1:15 pm-8:47 am

2 stops35h 32m

$1,190

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 8/1

7:20 am-6:50 am

2 stops32h 30m

Sydney Kingsford Smith

Sun 8/9

9:15 am-8:49 pm

2 stops26h 34m

$1,190

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 5/4

8:30 am-6:55 am

1 stop31h 25m

Sydney Kingsford Smith

Mon 5/18

10:20 am-6:22 pm

1 stop23h 02m

$1,199

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 5/16

4:44 pm-7:00 am

2 stops23h 16m

Sydney Kingsford Smith

Sat 5/23

10:20 am-6:17 pm

1 stop22h 57m

$1,225

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 5/2

8:30 am-6:55 am

1 stop31h 25m

Sydney Kingsford Smith

Sat 5/16

10:20 am-6:22 pm

1 stop23h 02m

$1,226

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 5/2

3:25 pm-6:50 am

2 stops24h 25m

Sydney Kingsford Smith

Sat 5/16

9:15 am-9:06 pm

2 stops26h 51m

$1,230

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 8/1

7:23 pm-6:55 am

1 stop20h 32m

Sydney Kingsford Smith

Sun 8/9

10:20 am-6:17 pm

1 stop22h 57m

$1,244

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/21

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Best time to book a flight from Illinois to Sydney

Have a flexible travel schedule? Discover the best time to fly to Sydney from Illinois with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

What is the cheapest month to book a flight from Illinois to Sydney?

Currently, August is the cheapest month in which you can book a flight from Illinois to Sydney (average of $198). Flying from Illinois to Sydney in October is currently the most expensive (average of $871). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

Related info for your journey

Find useful and relevant information for your journey from Illinois to Sydney. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Sydney from Illinois?

    If you book a flight to Sydney from Illinois, you will be flying to Kingsford Smith, which is the city’s only airport. Sydney Kingsford Smith (SYD) is located 4.6 mi from the center of Sydney.

  • How long is the flight from Illinois to Sydney?

    There are many flights that can get you from Illinois to Sydney in 26h 34m. Fly via Delta, United Airlines, or Turkish Airlines to get the fastest option. The distance from Illinois to Sydney is about 9119 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines to fly from Illinois to Sydney one-way?

    For one-way options, check prices for United Airlines. According to our data, you can fly for as low as $229. Users have also found prices from $404 and $612 on Qantas Airways and American Airlines, respectively.

  • What are the most popular routes from Illinois to Sydney?

    While some choose either Chicago Midway - Sydney Kingsford Smith or Lambert-St Louis - Sydney Kingsford Smith, Chicago O'Hare Intl - Sydney Kingsford Smith is the most popular route from Illinois to Sydney.

  • Can I find deals for flights from Illinois to Sydney that include hotel bookings?

    Yes. In addition to deals on Illinois to Sydney flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to Sydney?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to Sydney.

  • Can I find deals for business class flights from Illinois to Sydney?

    Yes. Cheapflights offers flight deals from Illinois to Sydney by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Illinois to Sydney?

    Currently, August is the cheapest month in which you can book a flight from Illinois to Sydney (average of $198). Flying from Illinois to Sydney in October is currently the most expensive (average of $871). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Sydney?

Book flights to Sydney if you plan to visit one of these locations
Parramatta
Wollongong
Manly

Browse thousands of different options on Cheapflights for your next trip

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Top 8 airlines flying from Illinois to Sydney

Discover the top 8 airlines that operate flights from Illinois to Sydney. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 25, 2026.
AirlineCheapestAverageFlexibilityOn-time
Fiji AirwaysCheapest$795Average$1,181FlexibilityNo cancel feeOn-time74%
American AirlinesCheapest$810Average$1,647FlexibilityNo cancel feeOn-time71%
Qantas AirwaysCheapest$812Average$1,145FlexibilityNo cancel feeOn-time74%
United AirlinesCheapest$870Average$1,233FlexibilityNo cancel feeOn-time69%
Air CanadaCheapest$890Average$1,244FlexibilityNo cancel feeOn-time67%
DeltaCheapest$936Average$1,034FlexibilityNo cancel feeOn-timeN/A
ANACheapest$1,177Average$1,237FlexibilityNo cancel feeOn-time80%
Air New ZealandCheapest$1,282Average$1,461FlexibilityNo cancel feeOn-time78%

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