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Cheap flights from Illinois to Sydney from $609

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 22/4. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SYD
10 Apr — 17 Apr1
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 11 March 2026.

Mon 20/405:15
ORD
-
SYD
2 stops39h 50m
Multiple Airlines
Mon 27/413:15
SYD
-
ORD
2 stops25h 12m
Multiple Airlines
Deal found 6/3$1,359
Tue 5/507:30
ORD
-
SYD
2 stops37h 20m
Multiple Airlines
Tue 12/506:00
SYD
-
ORD
2 stops32h 27m
Multiple Airlines
Deal found 8/3$1,372
Tue 2/612:44
ORD
-
SYD
2 stops32h 06m
Multiple Airlines
Sun 7/606:00
SYD
-
ORD
2 stops38h 23m
Multiple Airlines
Deal found 9/3$1,407
Thu 21/512:44
ORD
-
SYD
2 stops32h 06m
Multiple Airlines
Tue 26/506:00
SYD
-
ORD
2 stops38h 23m
Multiple Airlines
Deal found 8/3$1,443
Tue 21/407:30
ORD
-
SYD
2 stops34h 15m
Multiple Airlines
Tue 28/411:55
SYD
-
ORD
2 stops26h 32m
Multiple Airlines
Deal found 7/3$1,460
Sun 26/405:15
ORD
-
SYD
2 stops39h 35m
Multiple Airlines
Sat 9/513:15
SYD
-
ORD
2 stops31h 20m
Multiple Airlines
Deal found 8/3$1,467
Sun 26/414:00
ORD
-
SYD
2 stops30h 50m
Multiple Airlines
Sun 10/513:15
SYD
-
ORD
2 stops31h 20m
Multiple Airlines
Deal found 7/3$1,514
Mon 27/414:00
ORD
-
SYD
2 stops31h 05m
Multiple Airlines
Sun 10/513:15
SYD
-
ORD
2 stops31h 20m
Multiple Airlines
Deal found 8/3$1,519
Tue 21/407:30
ORD
-
SYD
2 stops34h 15m
Multiple Airlines
Sat 2/509:55
SYD
-
ORD
2 stops28h 32m
Multiple Airlines
Deal found 7/3$1,538
Thu 23/414:00
ORD
-
SYD
2 stops30h 50m
Multiple Airlines
Wed 6/513:20
SYD
-
ORD
2 stops31h 15m
Multiple Airlines
Deal found 6/3$1,577
Mon 20/406:21
STL
-
SYD
2 stops35h 59m
Qantas Airways
Mon 27/412:00
SYD
-
STL
1 stop20h 21m
Qantas Airways
Deal found 6/3$1,587
Wed 9/1215:59
STL
-
SYD
1 stop21h 56m
Qantas Airways
Tue 15/1207:00
SYD
-
STL
2 stops22h 32m
Qantas Airways
Deal found 7/3$1,608

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 11 March 2026.

Round-trip from

$1,359

One-way from

$609

Popular in

December

Cheapest in

February

Average price

$1,951
20/4-27/4
  • 20/4-27/4
  • 4 total stops
  • 65h 02m total
  • Illinois to Sydney
Search Deals
22/4
  • 22/4
  • 2 total stops
  • 47h 40m total
  • Illinois to Sydney
Search Deals
Highest demand for flights based on searches. 2% potential increase in price ($67 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 0% potential price decrease ($27 potential savings vs. average return price).
Search Deals
Average for round-trip flights in March 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 11 March 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

Thu 30/4

06:21-09:20

2 stops35h 59m

Sydney Kingsford Smith

Mon 4/5

12:00-19:30

1 stop22h 30m

$1,618

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 4/5

19:06-06:55

1 stop20h 49m

Sydney Kingsford Smith

Mon 18/5

10:20-18:22

1 stop23h 02m

$1,680

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 4/5

13:46-06:50

2 stops26h 04m

Sydney Kingsford Smith

Mon 18/5

09:15-21:09

2 stops26h 54m

$1,687

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 6/5

12:23-06:50

2 stops27h 27m

Sydney Kingsford Smith

Tue 18/8

09:15-20:31

2 stops26h 16m

$1,687

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 6/5

06:21-07:30

1 stop34h 09m

Sydney Kingsford Smith

Tue 18/8

09:10-23:08

1 stop28h 58m

$1,702

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 7/5

19:06-06:55

1 stop20h 49m

Sydney Kingsford Smith

Tue 12/5

10:20-18:22

1 stop23h 02m

$1,738

PeoriaSydney

PIA - SYD

PIASYD

Greater Peoria

Sat 11/7

14:39-07:00

2 stops25h 21m

Sydney Kingsford Smith

Fri 14/8

10:20-00:22

2 stops29h 02m

$1,844

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 6/5

14:35-10:40

3 stops29h 05m

Sydney Kingsford Smith

Tue 18/8

11:55-23:50

3 stops26h 55m

$1,854

PeoriaSydney

PIA - SYD

PIASYD

Greater Peoria

Sat 25/4

14:50-07:00

2 stops25h 10m

Sydney Kingsford Smith

Sat 9/5

09:30-22:49

2 stops28h 19m

$1,916

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 20/5

07:45-08:45

3 stops34h 00m

Sydney Kingsford Smith

Wed 10/6

11:55-23:57

3 stops27h 02m

$1,933

Flights are sorted by cheapest return flights first.

Deals found on 10/3

Showing 1-10 of 60 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 $279). Flying from Illinois to Sydney in October is currently the most expensive (average of $1,263). 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?

    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 49m. Qantas Airways provides one of the quickest options available for as low as $1,680. 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 $279). Flying from Illinois to Sydney in October is currently the most expensive (average of $1,263). 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
Manly
Katoomba
Terrigal
Lithgow
Bondi Beach
Coogee
Cronulla
Leura
Randwick

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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 11 March 2026.
AirlineCheapestAverageFlexibilityOn-time
Qantas AirwaysCheapest$1,903Average$2,289FlexibilityNo 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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