Find flights
When to book
FAQs

Cheap flights from Illinois to Sydney from $856

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 4/8. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SYD
22 Aug — 29 Aug1
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 23 July 2026.

Tue 1/906:00
STL
-
SYD
2 stops37h 55m
Qantas Airways
Mon 21/912:00
SYD
-
STL
1 stop21h 04m
Qantas Airways
Deal found 21/7$1,588
Wed 23/908:55
STL
-
SYD
2 stops31h 25m
Air Canada
Wed 7/1010:20
SYD
-
STL
2 stops24h 21m
Air Canada
Deal found 23/7$1,595
Sun 30/808:55
STL
-
SYD
2 stops31h 25m
Air Canada
Mon 14/909:20
SYD
-
STL
2 stops43h 40m
Air Canada
Deal found 22/7$1,602
Tue 17/1106:00
STL
-
SYD
3 stops34h 35m
Air Canada
Wed 25/1111:20
SYD
-
STL
2 stops45h 06m
Air Canada
Deal found 22/7$1,624
Sun 13/905:10
STL
-
SYD
2 stops35h 10m
Air Canada
Tue 22/909:20
SYD
-
STL
2 stops22h 14m
Air Canada
Deal found 23/7$1,625
Tue 13/1012:47
STL
-
SYD
1 stop26h 08m
Qantas Airways
Wed 18/1114:05
SYD
-
STL
1 stop21h 10m
Qantas Airways
Deal found 20/7$1,629
Sun 8/1116:43
PIA
-
SYD
1 stop21h 12m
Qantas Airways
Thu 12/1119:15
SYD
-
PIA
2 stops37h 33m
Qantas Airways
Deal found 22/7$1,638
Tue 13/1019:01
STL
-
SYD
3 stops45h 19m
Air Canada
Wed 18/1111:20
SYD
-
STL
2 stops45h 06m
Air Canada
Deal found 22/7$1,639
Mon 7/910:16
STL
-
SYD
1 stop29h 39m
Qantas Airways
Mon 14/912:00
SYD
-
STL
1 stop21h 04m
Qantas Airways
Deal found 20/7$1,644
Sun 30/810:16
STL
-
SYD
1 stop29h 39m
Qantas Airways
Mon 14/909:10
SYD
-
STL
1 stop29h 20m
Qantas Airways
Deal found 22/7$1,645
Mon 17/808:29
PIA
-
SYD
2 stops31h 31m
United Airlines
Mon 24/809:30
SYD
-
PIA
2 stops28h 13m
United Airlines
Deal found 20/7$1,704
Tue 1/917:05
ORD
-
SYD
1 stop22h 20m
Qantas Airways
Sun 6/918:05
SYD
-
ORD
2 stops36h 49m
Qantas Airways
Deal found 23/7$1,794

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 23 July 2026.

Round-trip from

$1,588

One-way from

$856

Popular in

September

Cheapest in

February

Average price

$2,207
Qantas Airways
  • Qantas Airways
  • 1/9-21/9
  • 3 total stops
  • 58h 59m total
  • Illinois to Sydney
Search Deals
4/8
  • 4/8
  • 3 total stops
  • 45h 47m total
  • Illinois to Sydney
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($175 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 0% potential price decrease ($29 potential savings vs. average return price).
Search Deals
Average for round-trip flights in July 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 23 July 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

PeoriaSydney

PIA - SYD

PIASYD

Greater Peoria

Sun 8/11

16:43-06:55

1 stop21h 12m

Sydney Kingsford Smith

Thu 12/11

19:15-15:48

2 stops37h 33m

$1,638

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 17/11

15:15-09:20

2 stops25h 05m

Sydney Kingsford Smith

Wed 25/11

09:15-14:13

1 stop21h 58m

$1,672

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 21/10

15:20-06:55

1 stop23h 35m

Sydney Kingsford Smith

Sun 25/10

19:40-23:46

2 stops44h 06m

$1,749

ChicagoSydney

MDW - SYD

MDWSYD

Chicago Midway

Sat 12/9

17:37-06:50

2 stops22h 13m

Sydney Kingsford Smith

Sun 27/9

09:15-22:44

2 stops28h 29m

$1,822

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 7/9

15:32-07:00

2 stops24h 28m

Sydney Kingsford Smith

Sun 27/9

09:30-18:16

2 stops23h 46m

$1,875

St. LouisSydney

STL - SYD

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

$1,875

ChicagoSydney

MDW - SYD

MDWSYD

Chicago Midway

Sat 12/9

17:37-06:50

2 stops22h 13m

Sydney Kingsford Smith

Fri 18/9

09:15-18:33

2 stops24h 18m

$1,894

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 8/9

16:40-07:00

2 stops23h 20m

Sydney Kingsford Smith

Thu 22/10

10:30-18:43

2 stops24h 13m

$1,939

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 13/10

06:04-08:05

1 stop34h 01m

Sydney Kingsford Smith

Fri 13/11

14:05-22:29

1 stop25h 24m

$1,978

ChicagoSydney

ORD - SYD

ORDSYD

Chicago O'Hare Intl

Thu 27/8

12:51-07:00

2 stops27h 09m

Sydney Kingsford Smith

Sun 6/9

09:30-20:04

2 stops25h 34m

$2,001

Flights are sorted by cheapest return flights first.

Deals found on 22/7

Showing 1-10 of 50 resultsSorted by cheapest first
1
2
3
...
5

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 $1,831). Flying from Illinois to Sydney in December is currently the most expensive (average of $2,440). 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 83 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 12m. Qantas Airways provides one of the quickest options available for as low as $1,638. The distance between Illinois and Sydney is about 14676 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 $1,831). Flying from Illinois to Sydney in December is currently the most expensive (average of $2,440). 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
Terrigal
Randwick
Leura
Bondi Beach
Coogee

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 23 July 2026.
AirlineCheapestAverageFlexibilityOn-time
Qantas AirwaysCheapest$2,100Average$2,325FlexibilityNo 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.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.