$128+ 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 18/4. 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
21 Apr — 28 Apr1
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 22 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

ChicagoBrisbane

ORD - BNE

ORDBNE

Chicago O'Hare Intl

Tue 5/5

07:30-10:40

2 stops36h 10m

Brisbane

Tue 12/5

11:35-22:04

2 stops25h 29m

$1,271

ChicagoBrisbane

ORD - BNE

ORDBNE

Chicago O'Hare Intl

Mon 13/7

08:45-07:05

1 stop31h 20m

Brisbane

Sun 26/7

10:00-13:07

2 stops42h 07m

$1,829

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 4/5

13:05-07:20

3 stops51h 15m

Sydney Kingsford Smith

Mon 11/5

09:20-20:25

3 stops50h 05m

$1,832

St. LouisMelbourne

STL - MEL

STLMEL

Lambert-St Louis

Tue 25/8

18:51-19:20

2 stops33h 29m

Melbourne

Thu 3/9

07:30-22:00

2 stops29h 30m

$1,899

St. LouisMelbourne

STL - MEL

STLMEL

Lambert-St Louis

Thu 21/5

13:38-08:15

2 stops27h 37m

Melbourne

Mon 10/8

10:55-20:43

2 stops24h 48m

$1,953

St. LouisMelbourne

STL - MEL

STLMEL

Lambert-St Louis

Thu 21/5

13:38-08:15

2 stops27h 37m

Melbourne

Sun 9/8

09:30-16:33

2 stops22h 03m

$1,953

St. LouisMelbourne

STL - MEL

STLMEL

Lambert-St Louis

Sat 23/5

19:23-08:15

1 stop21h 52m

Melbourne

Wed 12/8

10:55-18:24

1 stop22h 29m

$1,953

St. LouisMelbourne

STL - MEL

STLMEL

Lambert-St Louis

Wed 20/5

19:06-08:15

1 stop22h 09m

Melbourne

Sun 9/8

10:55-18:17

1 stop22h 22m

$1,953

St. LouisMelbourne

STL - MEL

STLMEL

Lambert-St Louis

Mon 27/7

14:57-07:30

2 stops25h 33m

Melbourne

Sat 8/8

10:55-21:26

2 stops25h 31m

$1,973

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 11/5

19:06-06:55

1 stop20h 49m

Sydney Kingsford Smith

Mon 18/5

10:20-18:22

1 stop23h 02m

$1,974

Flights are sorted by cheapest return flights first.

Deals found on 21/3

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 $282). Flying from Illinois in October will prove the most costly (average of $1,278). 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 22 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 $1,246 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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