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Cheap flights from Illinois to Sydney from $845

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 29/7. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SYD
10 Jul — 17 Jul1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Illinois to Sydney

Enter your travel dates to find the best prices.

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 10 June 2026.

Sun 15/1118:13
STL
-
SYD
2 stops33h 37m
Qantas Airways
Wed 25/1111:15
SYD
-
STL
1 stop29h 27m
Qantas Airways
Deal found 9/6$1,534
Tue 1/1218:13
STL
-
SYD
2 stops33h 37m
Qantas Airways
Tue 15/1211:15
SYD
-
STL
1 stop29h 42m
Qantas Airways
Deal found 9/6$1,676
Sat 8/812:10
STL
-
SYD
2 stops52h 10m
Air Canada
Sun 16/809:20
SYD
-
STL
2 stops48h 22m
Air Canada
Deal found 6/6$1,696
Sat 7/1120:00
ORD
-
SYD
2 stops31h 15m
ANA
Wed 18/1121:45
SYD
-
ORD
1 stop26h 35m
ANA
Deal found 8/6$1,860
Wed 26/817:45
ORD
-
SYD
1 stop34h 25m
ANA
Tue 1/911:45
SYD
-
ORD
2 stops32h 00m
ANA
Deal found 8/6$1,863
Mon 8/606:35
STL
-
SYD
1 stop33h 30m
Qantas Airways
Sun 21/609:10
SYD
-
STL
1 stop29h 46m
Qantas Airways
Deal found 7/6$1,865
Thu 13/817:45
ORD
-
SYD
1 stop24h 40m
ANA
Sun 23/820:55
SYD
-
ORD
2 stops34h 46m
ANA
Deal found 9/6$1,866
Fri 6/1116:25
ORD
-
SYD
1 stop34h 50m
ANA
Thu 19/1112:25
SYD
-
ORD
2 stops43h 50m
ANA
Deal found 8/6$1,868
Sun 21/608:45
ORD
-
SYD
1 stop31h 35m
Air Canada
Tue 7/709:20
SYD
-
ORD
1 stop20h 16m
Air Canada
Deal found 7/6$1,872
Mon 8/614:57
STL
-
SYD
2 stops24h 58m
United Airlines
Sun 21/610:20
SYD
-
STL
1 stop22h 57m
United Airlines
Deal found 7/6$1,872
Mon 24/819:50
ORD
-
SYD
2 stops46h 35m
ANA
Mon 31/811:45
SYD
-
ORD
2 stops32h 00m
ANA
Deal found 10/6$1,873
Fri 14/817:45
ORD
-
SYD
1 stop34h 25m
ANA
Wed 26/811:45
SYD
-
ORD
2 stops47h 48m
ANA
Deal found 9/6$1,876

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 10 June 2026.

Round-trip from

$1,534

One-way from

$845

Popular in

December

Cheapest in

February

Average price

$1,973
Qantas Airways
  • Qantas Airways
  • 15/11-25/11
  • 3 total stops
  • 63h 04m total
  • Illinois to Sydney
Search Deals
29/7
  • 29/7
  • 3 total stops
  • 58h 02m total
  • Illinois to Sydney
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($168 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($64 potential savings vs. average return price).
Search Deals
Average for round-trip flights in June 2026
Search Deals

Cheapflights Fare Finder

 
Customise 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 647,157 searches. Data last updated 10 June 2026.
Use the filters below to find and compare flights from Illinois to Sydney that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 8/8

19:23-06:55

1 stop20h 32m

Sydney Kingsford Smith

Sun 16/8

10:20-18:39

1 stop23h 19m

$1,969

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 3/7

15:22-06:55

2 stops24h 33m

Sydney Kingsford Smith

Fri 10/7

10:20-18:17

1 stop22h 57m

$2,027

EvansvilleSydney

EVV - SYD

EVVSYD

Evansville Dress Regional

Thu 23/7

12:46-06:55

2 stops27h 09m

Sydney Kingsford Smith

Thu 30/7

09:10-23:31

2 stops29h 21m

$2,041

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 24/7

05:10-07:00

2 stops34h 50m

Sydney Kingsford Smith

Fri 31/7

09:30-16:33

2 stops22h 03m

$2,069

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 23/9

16:40-07:00

2 stops23h 20m

Sydney Kingsford Smith

Wed 7/10

11:20-18:43

1 stop23h 23m

$2,078

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 7/9

08:42-06:55

1 stop31h 13m

Sydney Kingsford Smith

Mon 14/9

10:20-18:39

1 stop23h 19m

$2,080

EvansvilleSydney

EVV - SYD

EVVSYD

Evansville Dress Regional

Mon 19/10

17:30-08:05

2 stops22h 35m

Sydney Kingsford Smith

Tue 27/10

11:15-23:28

2 stops28h 13m

$2,081

ChicagoSydney

ORD - SYD

ORDSYD

Chicago O'Hare Intl

Tue 25/8

18:54-18:50

2 stops32h 56m

Sydney Kingsford Smith

Tue 1/9

20:45-06:20

3 stops24h 35m

$2,100
Fastest return journey

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 20/7

19:23-06:55

1 stop20h 32m

Sydney Kingsford Smith

Tue 28/7

10:20-18:17

1 stop22h 57m

$2,184

ChicagoSydney

ORD - SYD

ORDSYD

Chicago O'Hare Intl

Tue 1/9

14:22-18:50

2 stops37h 28m

Sydney Kingsford Smith

Tue 8/9

20:45-06:20

3 stops24h 35m

$2,190

Flights are sorted by cheapest return flights first.

Deals found on 6/6

Showing 1-10 of 55 resultsSorted by cheapest first
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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 return 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 $197). Flying from Illinois to Sydney in October is currently the most expensive (average of $1,185). 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.

How much does it cost for a return flight from Illinois to Sydney?

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

The price you pay for your flight from Illinois to Sydney may vary depending on when you book. For the best chance of a lower fare, look to book 46 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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?

    Located just 7.5 km from the city centre, Sydney Kingsford Smith (SYD) is the airport most travelers will use when flying to Sydney from Illinois.

  • How long is the flight from Illinois to Sydney?

    A quick flight from Illinois to Sydney can take about 20h 32m. United Airlines provides one of the quickest options available for as low as $1,969. The distance between Illinois and Sydney is about 14571 km. Both multi-stop and direct flights can be found to your destination and back.

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

    When deciding which route to take from Illinois to Sydney, consider Chicago O'Hare Intl - Sydney Kingsford Smith, Chicago Midway - Sydney Kingsford Smith or Lambert-St Louis - Sydney Kingsford Smith, as they are the most popular.

  • 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 holiday 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 $197). Flying from Illinois to Sydney in October is currently the most expensive (average of $1,185). 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

Travelling to a place near Sydney?

Book flights to Sydney if you plan to visit one of these locations
Parramatta
Wollongong
Penrith
Katoomba
Cronulla
Manly
Terrigal
Lithgow
Randwick
Bondi Beach
Leura
Coogee

Browse thousands of different options on Cheapflights for your next trip

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Top airline flying from Illinois to Sydney

Discover the top airline 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 647,157 searches. Data last updated 10 June 2026.
AirlineCheapestAverageFlexibilityOn-time
Qantas AirwaysCheapest$2,095Average$2,320FlexibilityNo cancel feeOn-time74%
Search Qantas Airways flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Illinois to Sydney?

When you search for this flight from Illinois to Sydney, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from Illinois to Sydney?

Millions of users choose and trust Cheapflights to book the best flight deals from Illinois to Sydney for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

Can Cheapflights find flights from Illinois to Sydney with no change fees?

Yes! Cheapflights helps users easily find flights from Illinois to Sydney with no change fees.

Can Cheapflights notify me if prices for flights from Illinois to Sydney become cheaper?

Of course! You can now track prices for flights from Illinois to Sydney and get an alert from Cheapflights when they change. Have a valid email address ready and click the bell icon next to the flight deals above to set up your price alerts.

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