Cheap flights from Illinois to Sydney from $799
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 9/11. Fares are subject to change and may not be available on all flights or dates of travel.
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 18 September 2025.
Round-trip from | $1,511 |
---|---|
One-way from | $799 |
Popular in | December |
Cheapest in | August |
Average price | $1,497 |
Find flight deals from Illinois to Sydney
Cheapest flights from Illinois to SydneyExplore 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 18 September 2025.
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 18 September 2025.
Cheapflights Fare Finder
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
St. LouisSydney
STL - SYD
STLSYD
Lambert-St Louis
Wed 5/11
15:59-07:35
2 stops46h 36m
Sydney Kingsford Smith
Sun 23/11
11:20-23:42
1 stop29h 22m
PeoriaSydney
PIA - SYD
PIASYD
Greater Peoria
Mon 29/9
06:00-07:00
2 stops34h 00m
Sydney Kingsford Smith
Sat 4/10
10:20-21:27
2 stops26h 07m
St. LouisSydney
STL - SYD
STLSYD
Lambert-St Louis
Wed 29/10
06:39-09:00
1 stop34h 21m
Sydney Kingsford Smith
Sat 15/11
19:15-17:08
2 stops38h 53m
ChicagoSydney
ORD - SYD
ORDSYD
Chicago O'Hare Intl
Wed 12/11
10:00-07:25
2 stops28h 25m
Sydney Kingsford Smith
Mon 17/11
17:45-23:00
1 stop22h 15m
PeoriaSydney
PIA - SYD
PIASYD
Greater Peoria
Fri 31/10
17:18-09:05
2 stops23h 47m
Sydney Kingsford Smith
Fri 7/11
11:50-20:56
2 stops26h 06m
PeoriaSydney
PIA - SYD
PIASYD
Greater Peoria
Sun 2/11
15:30-09:05
2 stops24h 35m
Sydney Kingsford Smith
Sun 9/11
12:10-10:16
2 stops39h 06m
PeoriaSydney
PIA - SYD
PIASYD
Greater Peoria
Tue 16/12
13:15-09:15
2 stops27h 00m
Sydney Kingsford Smith
Thu 8/1
11:20-10:10
2 stops39h 50m
ChicagoSydney
ORD - SYD
ORDSYD
Chicago O'Hare Intl
Tue 28/10
18:16-12:45
2 stops26h 29m
Sydney Kingsford Smith
Tue 11/11
14:10-19:40
2 stops22h 30m
St. LouisSydney
STL - SYD
STLSYD
Lambert-St Louis
Wed 29/10
06:39-12:45
2 stops38h 06m
Sydney Kingsford Smith
Thu 13/11
14:00-22:29
2 stops25h 29m
St. LouisSydney
STL - SYD
STLSYD
Lambert-St Louis
Wed 5/11
16:35-07:00
1 stop21h 25m
Sydney Kingsford Smith
Sun 23/11
11:50-18:47
1 stop23h 57m
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.
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, May is the cheapest month in which you can book a flight from Illinois to Sydney (average of $129). Flying from Illinois to Sydney in October is currently the most expensive (average of $171). 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 18 September 2025.
When flying from Illinois to Sydney, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
How much does it cost for a return flight from Illinois to Sydney?
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.
Travelling to a place near Sydney?
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Alternative routes for Illinois to Sydney
See prices for flight routes from nearby airports that may be better suited for you.
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 18 September 2025.
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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.