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Cheap flights from Illinois to Sydney from $851

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 13/11. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SYD
6 Sep — 13 Sep1
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 7 August 2026.

Wed 21/1014:10 -
2 stops26h 35m
Mon 9/1109:55 -
2 stops26h 01m
Deal found 5/8$1,737
Tue 1/916:45 -
2 stops26h 55m
Tue 8/909:55 -
2 stops26h 40m
Deal found 7/8$1,738
Sun 9/809:15 -
2 stops30h 35m
Sun 23/809:15 -
2 stops24h 40m
Deal found 5/8$1,747
Wed 26/821:20 -
1 stop43h 10m
Tue 8/913:15 -
2 stops32h 02m
Deal found 3/8$1,750
Sun 23/810:27 -
2 stops33h 13m
Tue 8/909:55 -
2 stops28h 10m
Deal found 5/8$1,754
Sun 27/911:00 -
2 stops41h 10m
Mon 12/1021:45 -
1 stop26h 55m
Deal found 5/8$1,761
Sun 15/1114:40 -
2 stops24h 55m
Tue 1/1219:25 -
2 stops40h 29m
Deal found 7/8$1,764
Sun 1/1114:40 -
2 stops26h 55m
Sun 15/1114:05 -
2 stops45h 51m
Deal found 6/8$1,767
Sun 9/806:00 -
1 stop34h 05m
Sun 23/817:50 -
1 stop20h 09m
Deal found 5/8$1,768
Sat 24/1020:09 -
2 stops44h 26m
Mon 9/1111:50 -
2 stops24h 06m
Deal found 7/8$1,772
Fri 7/812:45 -
2 stops27h 20m
Mon 17/812:00 -
1 stop21h 05m
Deal found 3/8$1,815
Mon 26/1014:55 -
2 stops25h 40m
Wed 11/1119:25 -
2 stops44h 00m
Deal found 6/8$1,851

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 7 August 2026.

Round-trip from

$1,737

One-way from

$851

Popular in

September

Cheapest in

February

Average price

$2,079
Air New Zealand
  • Air New Zealand
  • 21/10-9/11
  • 4 total stops
  • 52h 36m total
  • Illinois to Sydney
Search Deals
13/11
  • 13/11
  • 3 total stops
  • 52h 35m total
  • Illinois to Sydney
Search Deals
Highest demand for flights based on searches. 6% potential increase in price ($211 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($36 potential savings vs. average return price).
Search Deals
Average for round-trip flights in August 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 7 August 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 Lambert-St Louis - SYD Sydney Kingsford Smith

STLSYD

Lambert-St Louis

Sat 14/11

19:05-09:40

2 stops45h 35m

Sydney Kingsford Smith

Wed 18/11

09:15-18:38

1 stop26h 23m

$1,875
Fastest return journey

St. LouisSydney

STL Lambert-St Louis - SYD Sydney Kingsford Smith

STLSYD

Lambert-St Louis

Tue 13/10

12:47-06:25

2 stops25h 38m

Sydney Kingsford Smith

Wed 18/11

14:05-18:15

1 stop21h 10m

$1,886

St. LouisSydney

STL Lambert-St Louis - SYD Sydney Kingsford Smith

STLSYD

Lambert-St Louis

Mon 7/9

08:42-06:55

1 stop31h 13m

Sydney Kingsford Smith

Sun 27/9

09:30-18:43

2 stops24h 13m

$1,886

St. LouisSydney

STL Lambert-St Louis - SYD Sydney Kingsford Smith

STLSYD

Lambert-St Louis

Wed 23/9

15:52-06:50

2 stops23h 58m

Sydney Kingsford Smith

Wed 7/10

10:15-18:15

2 stops24h 00m

$1,893

St. LouisSydney

STL Lambert-St Louis - SYD Sydney Kingsford Smith

STLSYD

Lambert-St Louis

Wed 23/9

15:32-07:00

2 stops24h 28m

Sydney Kingsford Smith

Wed 7/10

11:20-18:43

1 stop23h 23m

$1,893

St. LouisSydney

STL Lambert-St Louis - SYD Sydney Kingsford Smith

STLSYD

Lambert-St Louis

Wed 16/9

16:40-06:55

2 stops23h 15m

Sydney Kingsford Smith

Wed 23/9

10:20-22:27

2 stops27h 07m

$1,933

PeoriaSydney

PIA Greater Peoria - SYD Sydney Kingsford Smith

PIASYD

Greater Peoria

Mon 26/10

16:42-06:55

1 stop22h 13m

Sydney Kingsford Smith

Fri 30/10

06:00-15:53

2 stops25h 53m

$1,968

PeoriaSydney

PIA Greater Peoria - SYD Sydney Kingsford Smith

PIASYD

Greater Peoria

Sat 19/9

08:29-06:55

2 stops31h 26m

Sydney Kingsford Smith

Sat 26/9

09:30-22:58

2 stops28h 28m

$2,076

PeoriaSydney

PIA Greater Peoria - SYD Sydney Kingsford Smith

PIASYD

Greater Peoria

Wed 11/11

16:43-06:55

1 stop21h 12m

Sydney Kingsford Smith

Sun 15/11

06:05-15:48

2 stops26h 43m

$2,183

ChicagoSydney

ORD Chicago O'Hare Intl - SYD Sydney Kingsford Smith

ORDSYD

Chicago O'Hare Intl

Sat 16/1

18:30-08:30

1 stop21h 00m

Sydney Kingsford Smith

Sat 30/1

10:40-21:37

2 stops27h 57m

$2,291

Flights are sorted by cheapest return flights first.

Deals found on 5/8

Showing 1-10 of 57 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, February is the cheapest month in which you can book a flight from Illinois to Sydney (average of $1,819). Flying from Illinois to Sydney in December is currently the most expensive (average of $2,451). 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?

Airfare is below average for this route at the moment.
Illinois to Sydney flights typically cost between $1,788 and $2,223 in October.
The cheapest return price found within the last 5 days was $1,737 on Air New Zealand (21 Oct–9 Nov).

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 82 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 21h. United Airlines provides one of the quickest options available for as low as $2,291. 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, February is the cheapest month in which you can book a flight from Illinois to Sydney (average of $1,819). Flying from Illinois to Sydney in December is currently the most expensive (average of $2,451). 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
Manly
Lithgow
Cronulla
Randwick
Terrigal
Leura
Bondi Beach
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 7 August 2026.
AirlineCheapestAverageFlexibilityOn-time
Qantas AirwaysCheapest$2,087Average$2,311FlexibilityNo 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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