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Cheap flights from Illinois to Sydney from $755

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 9/2. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SYD
26 Dec — 2 Jan1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Illinois to Sydney

Keep the following information in mind while searching for Illinois to Sydney flight deals. Data was last updated 26 November 2025.

Round-trip from

$1,390

One-way from

$755

Popular in

December

Cheapest in

August

Average price

$1,474
Qantas Airways
  • Qantas Airways
  • 21/1-3/2
  • 3 total stops
  • 52h 29m total
  • Illinois to Sydney
Search Deals
9/2
  • 9/2
  • 3 total stops
  • 34h 35m total
  • Illinois to Sydney
Search Deals
Highest demand for flights based on searches. 15% potential increase in price ($408 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($91 potential savings vs. average return price).
Search Deals
Average for round-trip flights in November 2025
Search Deals

Find 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 26 November 2025.

Mon 1/1218:23ORD - SYD
1 stop21h 37mQantas Airways
Sat 17/117:50SYD - ORD
2 stops37h 20mQantas Airways
Deal found 24/11$1,503
Mon 22/1216:34ORD - SYD
1 stop23h 26mQantas Airways
Fri 16/119:15SYD - ORD
2 stops36h 42mQantas Airways
Deal found 23/11$1,549
Fri 28/1107:00STL - SYD
2 stops33h 50mQantas Airways
Sun 14/1214:05SYD - STL
1 stop20h 00mQantas Airways
Deal found 26/11$1,656
Wed 10/1213:20STL - SYD
1 stop24h 35mQantas Airways
Sat 10/121:55SYD - STL
2 stops33h 52mQantas Airways
Deal found 25/11$1,681
Wed 3/1213:20STL - SYD
1 stop24h 35mQantas Airways
Wed 10/1217:30SYD - STL
2 stops23h 27mQantas Airways
Deal found 25/11$1,706
Sun 7/1206:50ORD - SYD
1 stop31h 35mMultiple Airlines
Sun 28/1211:20SYD - ORD
1 stop21h 29mMultiple Airlines
Deal found 24/11$1,828
Mon 1/1209:24ORD - SYD
2 stops29h 01mMultiple Airlines
Mon 15/1217:45SYD - ORD
1 stop29h 20mMultiple Airlines
Deal found 24/11$1,997
Wed 3/1206:55STL - SYD
2 stops35h 00mQantas Airways
Fri 12/1217:00SYD - STL
2 stops23h 57mQantas Airways
Deal found 25/11$2,017
Wed 3/1206:55STL - SYD
2 stops36h 20mQantas Airways
Sat 13/1219:40SYD - STL
2 stops33h 54mQantas Airways
Deal found 25/11$2,028
Tue 2/1209:00STL - SYD
2 stops31h 35mAir Canada
Sat 13/1211:20SYD - STL
2 stops42h 19mAir Canada
Deal found 25/11$2,032
Mon 1/1216:05STL - SYD
2 stops45h 50mAir Canada
Sat 13/1216:00SYD - STL
2 stops37h 39mAir Canada
Deal found 25/11$2,043
Thu 27/1108:10ORD - SYD
1 stop30h 15mMultiple Airlines
Sun 7/1217:45SYD - ORD
1 stop23h 28mMultiple Airlines
Deal found 25/11$2,062

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 26 November 2025.
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

Sat 31/1

07:04-20:50

2 stops44h 46m

Sydney Kingsford Smith

Sat 28/2

17:45-23:48

1 stop23h 03m

$1,529

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 31/1

16:05-09:35

2 stops48h 30m

Sydney Kingsford Smith

Sat 28/2

11:20-20:26

2 stops26h 06m

$1,563

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 4/5

13:30-07:20

2 stops26h 50m

Sydney Kingsford Smith

Mon 18/5

09:20-15:16

2 stops44h 56m

$1,588

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 4/5

13:30-07:20

3 stops50h 50m

Sydney Kingsford Smith

Mon 18/5

09:20-15:16

2 stops44h 56m

$1,591

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 10/12

13:20-06:55

1 stop24h 35m

Sydney Kingsford Smith

Sat 10/1

21:55-14:47

2 stops33h 52m

$1,681

ChicagoSydney

ORD - SYD

ORDSYD

Chicago O'Hare Intl

Sat 14/3

19:13-09:00

1 stop21h 47m

Sydney Kingsford Smith

Fri 3/4

13:00-17:48

1 stop20h 48m

$1,771

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 4/5

16:09-06:55

1 stop23h 46m

Sydney Kingsford Smith

Mon 18/5

12:00-18:17

1 stop21h 17m

$1,772

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 2/5

16:09-06:55

1 stop23h 46m

Sydney Kingsford Smith

Sat 16/5

12:00-16:11

1 stop19h 11m

$1,772

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 20/1

11:55-06:55

1 stop26h 00m

Sydney Kingsford Smith

Tue 27/1

14:05-16:14

1 stop19h 09m

$1,772

ChicagoSydney

ORD - SYD

ORDSYD

Chicago O'Hare Intl

Sun 18/1

13:55-08:30

2 stops25h 35m

Sydney Kingsford Smith

Sun 1/2

10:40-21:05

2 stops27h 25m

$1,782

Flights are sorted by cheapest return flights first.

Deals found on 25/11

Showing 1-10 of 57 results
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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 $306). Flying from Illinois to Sydney in January is currently the most expensive (average of $1,316). 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.

What is the cheapest time of day to fly from IL to SYD?

Find hourly flight availability from Illinois to Sydney. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 26 November 2025.

Unlike at midday, when flights are generally more expensive, you can save up to 39% on flights from Illinois to Sydney by exploring options for tickets in the afternoon.

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 25h 35m. Qantas Airways provides one of the quickest options available for as low as $1,782. The distance between Illinois and Sydney is about 14851 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 $306). Flying from Illinois to Sydney in January is currently the most expensive (average of $1,316). 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
Katoomba
Penrith
Terrigal
Manly
Randwick
Lithgow
Coogee
Leura
Bondi Beach
Cronulla

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Top 2 airlines flying from Illinois to Sydney

Discover the top 2 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 647,157 searches. Data last updated 26 November 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$1,326Average$1,340FlexibilityNo cancel feeOn-time71%
Search American Airlines flights
Qantas AirwaysCheapest$1,353Average$2,449FlexibilityNo 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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