$170+ Cheap flights from Illinois

This is the cheapest return flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 7/4. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
ORD — SYD
27 Apr — 4 May1
1 adult
1 adult, Economy, 0 bags

Find flights from Illinois within your budget

 
Find flights departing from Illinois that match your specified budget. Filter results by price range, allowing you to narrow down options and find flights that fit within your financial constraints. Please note that the search results are based on data from user searches, with fares last updated on 28 March 2026. In the last 7 days, Cheapflights users made a total of 647,157 searches

Fly to

Route

Depart

Return

Price

Cheapest return flight

St. LouisBrisbane

STL - BNE

STLBNE

Lambert-St Louis

Tue 14/4

16:30-07:05

2 stops23h 35m

Brisbane

Mon 8/6

10:00-20:43

2 stops49h 43m

$1,433

St. LouisBrisbane

STL - BNE

STLBNE

Lambert-St Louis

Tue 8/9

12:10-07:05

2 stops27h 55m

Brisbane

Mon 28/9

10:00-20:00

2 stops25h 00m

$1,678

St. LouisBrisbane

STL - BNE

STLBNE

Lambert-St Louis

Sat 27/6

16:45-07:05

2 stops23h 20m

Brisbane

Sun 5/7

10:00-18:42

2 stops47h 42m

$1,686

ChicagoAdelaide

ORD - ADL

ORDADL

Chicago O'Hare Intl

Sun 10/5

14:15-11:50

3 stops31h 05m

Adelaide

Sun 17/5

20:00-14:45

2 stops33h 15m

$1,697

St. LouisBrisbane

STL - BNE

STLBNE

Lambert-St Louis

Tue 8/9

12:10-07:05

2 stops51h 55m

Brisbane

Mon 28/9

20:40-20:00

3 stops38h 20m

$1,720

St. LouisBrisbane

STL - BNE

STLBNE

Lambert-St Louis

Sun 10/5

13:05-07:05

2 stops27h 00m

Brisbane

Sun 17/5

10:00-20:25

2 stops49h 25m

$1,780

St. LouisBrisbane

STL - BNE

STLBNE

Lambert-St Louis

Thu 7/5

14:15-14:30

3 stops33h 15m

Brisbane

Thu 14/5

10:00-20:25

2 stops25h 25m

$1,794

ChicagoAdelaide

ORD - ADL

ORDADL

Chicago O'Hare Intl

Fri 8/5

14:15-15:55

3 stops35h 10m

Adelaide

Tue 12/5

20:00-14:45

2 stops33h 15m

$1,806

St. LouisBrisbane

STL - BNE

STLBNE

Lambert-St Louis

Sun 3/5

06:21-05:00

1 stop31h 39m

Brisbane

Sun 10/5

15:30-19:30

2 stops43h 00m

$1,956

St. LouisBrisbane

STL - BNE

STLBNE

Lambert-St Louis

Wed 6/5

06:21-05:00

1 stop31h 39m

Brisbane

Sat 16/5

14:00-17:21

2 stops42h 21m

$1,964

Flights are sorted by cheapest return flights first.

Deals found on 24/3

Showing 1-10 of 60 resultsSorted by cheapest first
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Best time to book a flight from Illinois

Have a flexible travel schedule? Discover the best time to fly 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.

Travel insights for flights from Illinois

Get recent, data-driven insights about flights from Illinois including ideal travel times, pricing trends, and more.

What is the cheapest month to book a flight from Illinois?

Currently, August is the cheapest month in which you can book a flight from Illinois (average of $287). Flying from Illinois in October will prove the most costly (average of $1,304). There are multiple factors that influence the price of a flight so comparing airlines, departure airports and times can help keep costs down.

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Direct flights from USA

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Related info for your journey

Access useful and relevant information related to your journey from Illinois. This can include details such as airport transportation, visa requirements, travel insurance, luggage regulations, and any other information that can ensure a smooth and hassle-free travel experience. Please note that the information is based on general guidance and may need to be verified with official sources. Data last updated 28 March 2026.
  • What is the cheapest month to fly from Illinois?

    Currently, the cheapest month for flights from Illinois is August. The most expensive month for flights is October. The cheapest prices are shown above but prices will vary according to departure times, airlines, class and how early you book.

  • Where are the cheapest places to fly to from Illinois?

    View the cheapest flight destinations from Illinois:
    Fly from Chicago to Sydney from $1,305 round trip
    Fly from Chicago to Melbourne from $1,395 round trip

  • How does Cheapflights help users find flights from Illinois?

    Deals for flights from Illinois are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose to your preference, such as price, airport, cabin class, and plenty of other options.

  • Why should you use Cheapflights to find cheap flight tickets from Illinois?

    Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Illinois for you. Better yet — we are completely free to use.

  • Can Cheapflights find flights from Illinois with no change fees?

    Users can book flights with no change fees policies with our dedicated filters. Book flights from Illinois flexibly with Cheapflights today.

  • Can Cheapflights notify me if prices for flights from Illinois become cheaper?

    Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and use a valid email address to enable the Price Alerts feature. That’s it!

See more FAQs

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?

Deals for flights from Illinois are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose to your preference, such as price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Illinois?

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Illinois for you. Better yet — we are completely free to use.

Can Cheapflights find flights from Illinois with no change fees?

Users can book flights with no change fees policies with our dedicated filters. Book flights from Illinois flexibly with Cheapflights today.

Can Cheapflights notify me if prices for flights from Illinois become cheaper?

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and use a valid email address to enable the Price Alerts feature. That’s it!

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