Find flights
When to book
FAQs

Cheap flights from St. Louis to Sydney from $857

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 25/1. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SYD
17 Dec — 24 Dec1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from St. Louis to Sydney

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Sydney (SYD). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 17 November 2025.

Round-trip from

$1,469

One-way from

$857

Popular in

December

Cheapest in

August

Average price

$2,082
Qantas Airways
  • Qantas Airways
  • 1/12-6/12
  • 3 total stops
  • 66h 52m total
  • St. Louis to Sydney
Search Deals
25/1
  • 25/1
  • 2 total stops
  • 25h 22m total
  • St. Louis to Sydney
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($201 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($66 potential savings vs. average return price).
Search Deals
Average for round-trip flights in November 2025
Search Deals

Find flight deals from St. Louis to Sydney

Enter your travel dates to find the best prices.

Cheapest flights from St. Louis to Sydney
Explore the most affordable flight options available from St. Louis to Sydney. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 17 November 2025.

Mon 1/1207:00STL - SYD
1 stop33h 00mQantas Airways
Sat 6/1207:05SYD - STL
2 stops33h 52mQantas Airways
Deal found 15/11$1,469
Mon 8/1217:30STL - SYD
2 stops34h 20mQantas Airways
Wed 17/1217:45SYD - STL
1 stop23h 12mQantas Airways
Deal found 16/11$1,499
Fri 28/1113:20STL - SYD
2 stops40h 05mQantas Airways
Sun 14/1214:05SYD - STL
1 stop22h 22mQantas Airways
Deal found 15/11$1,675
Fri 28/1116:05STL - SYD
2 stops45h 50mAir Canada
Mon 15/1211:20SYD - STL
2 stops42h 19mAir Canada
Deal found 15/11$1,773
Fri 12/1217:30STL - SYD
1 stop20h 25mQantas Airways
Wed 31/1217:30SYD - STL
2 stops23h 21mQantas Airways
Deal found 16/11$1,883
Tue 18/1111:42STL - SYD
1 stop26h 13mQantas Airways
Thu 20/1121:55SYD - STL
2 stops35h 32mQantas Airways
Deal found 14/11$1,958
Mon 1/1216:05STL - SYD
2 stops45h 50mAir Canada
Sat 6/1211:20SYD - STL
2 stops45h 09mAir Canada
Deal found 15/11$1,986
Fri 28/1113:35STL - SYD
2 stops27h 00mAir Canada
Sun 14/1211:20SYD - STL
2 stops42h 19mAir Canada
Deal found 16/11$2,187

Cheapflights Fare Finder

 
Customise your flight search to find flights from St. Louis 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 17 November 2025.
Use the filters below to find and compare flights from St. Louis to Sydney that are best for you.

Fly from

St. Louis

Fly to

Sydney

Route

Depart

Return

Price

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 12/12

17:30-06:55

1 stop20h 25m

Sydney Kingsford Smith

Wed 31/12

17:30-23:51

2 stops23h 21m

$1,883

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 10/4

16:09-06:55

1 stop23h 46m

Sydney Kingsford Smith

Fri 24/4

12:00-16:11

1 stop19h 11m

$1,952

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 10/4

18:00-06:55

1 stop21h 55m

Sydney Kingsford Smith

Fri 24/4

12:00-16:11

1 stop19h 11m

$1,952

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 4/5

13:30-07:00

2 stops26h 30m

Sydney Kingsford Smith

Mon 18/5

10:20-18:22

1 stop23h 02m

$1,982

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 16/2

17:25-09:15

1 stop22h 50m

Sydney Kingsford Smith

Mon 23/2

11:50-15:38

1 stop20h 48m

$2,236

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 14/2

16:30-07:00

2 stops45h 30m

Sydney Kingsford Smith

Sun 22/2

11:50-15:38

1 stop20h 48m

$2,243

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 9/1

14:50-19:45

2 stops59h 55m

Sydney Kingsford Smith

Tue 20/1

21:40-13:54

2 stops33h 14m

$2,292

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 10/1

18:19-19:45

2 stops32h 26m

Sydney Kingsford Smith

Fri 16/1

21:40-13:54

2 stops57h 14m

$2,353

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 9/1

14:50-19:45

2 stops59h 55m

Sydney Kingsford Smith

Sat 17/1

21:40-13:54

2 stops33h 14m

$2,356

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 14/12

17:30-09:40

2 stops47h 10m

Sydney Kingsford Smith

Sun 21/12

11:20-22:22

2 stops28h 02m

$2,455

Flights are sorted by cheapest return flights first.

Deals found on 16/11

Showing 1-10 of 19 results
1
2

Best time to book a flight from St. Louis to Sydney

Have a flexible travel schedule? Discover the best time to fly to Sydney from St. Louis 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 St. Louis to Sydney

What is the cheapest month to book a flight from St. Louis to Sydney?

Currently, August is the cheapest month in which you can book a flight from St. Louis to Sydney (average of $1,078). Flying from St. Louis to Sydney in February is currently the most expensive (average of $1,935). 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 St. Louis to Sydney?

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Sydney. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from St. Louis to Sydney?

    A quick flight from St. Louis to Sydney can take about 20h 25m. Qantas Airways provides one of the quickest options available for as low as $1,883. There are 14571 km between St. Louis and Sydney. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • Can I find deals for flights from St. Louis to Sydney that include hotel bookings?

    Yes. In addition to deals on St. Louis to Sydney flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Sydney?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Sydney.

  • Can I find deals for business class flights from St. Louis to Sydney?

    Yes. Cheapflights offers flight deals from St. Louis 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 St. Louis to Sydney?

    Currently, August is the cheapest month in which you can book a flight from St. Louis to Sydney (average of $1,078). Flying from St. Louis to Sydney in February is currently the most expensive (average of $1,935). 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
Katoomba
Penrith
Terrigal
Manly
Randwick
Lithgow
Coogee
Leura
Bondi Beach
Cronulla

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.

Alternative routes for St. Louis to Sydney

See prices for flight routes from nearby airports that may be better suited for you.
Kansas City to Sydney 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 St. Louis to Sydney?

900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Sydney from St. Louis today with Cheapflights!

Why should you use Cheapflights to find cheap flight tickets from St. Louis to Sydney?

By finding flights from multiple airlines and providers at completely no cost, Cheapflights helps millions of users like you annually find the best flights to Sydney from St. Louis.

Can Cheapflights find flights from St. Louis to Sydney with no change fees?

Need flexible booking options for your flight to Sydney from St. Louis? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

Can Cheapflights notify me if prices for flights from St. Louis to Sydney become cheaper?

Yes! Start tracking prices for St. Louis to Sydney flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your 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.