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Cheap flights from St. Louis to Sydney from $852

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 25/11. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SYD
1 Nov — 8 Nov1
1 adult
1 adult, Economy

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 2 October 2025.

Round-trip from

$1,949

One-way from

$852

Popular in

December

Cheapest in

August

Average price

$2,057
Air New Zealand
  • Air New Zealand
  • 22/2-2/3
  • 4 total stops
  • 72h 23m total
  • St. Louis to Sydney
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25/11
  • 25/11
  • 2 total stops
  • 57h 50m total
  • St. Louis to Sydney
Search Deals
Highest demand for flights based on searches. 6% potential increase in price ($221 potential increase over avg. return price).
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Cheapest flight prices on average. 2% potential price decrease ($71 potential savings vs. average return price).
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Average for round-trip flights in October 2025
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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 2 October 2025.

Wed 5/1116:35STL - SYD
1 stop21h 25mUnited Airlines
Sun 23/1111:50SYD - STL
1 stop21h 00mUnited Airlines
Deal found 30/9$1,953
Sun 23/1116:43STL - SYD
2 stops23h 32mUnited Airlines
Sun 7/1214:00SYD - STL
1 stop19h 27mUnited Airlines
Deal found 1/10$1,955
Sat 15/1117:29STL - SYD
2 stops48h 01mAir New Zealand
Sat 22/1119:15SYD - STL
2 stops40h 32mAir New Zealand
Deal found 1/10$1,995
Fri 28/1106:15STL - SYD
2 stops35h 15mAir New Zealand
Sun 14/1209:55SYD - STL
2 stops29h 03mAir New Zealand
Deal found 30/9$1,997
Fri 14/1108:20STL - SYD
2 stops31h 25mAir New Zealand
Fri 21/1111:45SYD - STL
2 stops24h 02mAir New Zealand
Deal found 30/9$2,068
Tue 14/1017:09STL - SYD
2 stops37h 01mMultiple Airlines
Fri 17/1017:20SYD - STL
2 stops22h 43mMultiple Airlines
Deal found 30/9$2,085
Wed 5/1113:35STL - SYD
3 stops26h 10mMultiple Airlines
Sun 23/1109:55SYD - STL
2 stops25h 52mMultiple Airlines
Deal found 30/9$2,150
Wed 29/1013:35STL - SYD
3 stops28h 55mMultiple Airlines
Sat 15/1111:45SYD - STL
3 stops27h 09mMultiple Airlines
Deal found 30/9$2,157

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 2 October 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

Sun 22/2

06:00-08:45

2 stops33h 45m

Sydney Kingsford Smith

Mon 2/3

11:45-09:23

2 stops38h 38m

$1,949

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 22/2

16:39-07:00

1 stop21h 21m

Sydney Kingsford Smith

Mon 2/3

12:10-16:44

1 stop21h 34m

$1,953

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 5/11

16:35-07:00

1 stop21h 25m

Sydney Kingsford Smith

Sun 23/11

11:50-15:50

1 stop21h 00m

$1,953

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 23/11

17:29-09:15

1 stop22h 46m

Sydney Kingsford Smith

Sun 7/12

12:10-16:27

1 stop21h 17m

$1,955

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 5/11

13:35-08:45

3 stops26h 10m

Sydney Kingsford Smith

Sun 23/11

09:55-18:47

2 stops25h 52m

$2,150

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 29/10

13:35-10:30

3 stops28h 55m

Sydney Kingsford Smith

Sat 15/11

11:45-21:54

3 stops27h 09m

$2,157

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 28/11

11:20-07:00

1 stop26h 40m

Sydney Kingsford Smith

Sun 14/12

11:50-21:58

1 stop27h 08m

$2,157

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 25/11

07:00-09:50

2 stops57h 50m

$852

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 19/11

07:00-09:50

2 stops57h 50m

$855

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 29/10

07:00-09:50

2 stops58h 50m

$855

Flights are sorted by cheapest return flights first.

Deals found on 30/9

Showing 1-10 of 13 results
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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

How far ahead should I book a flight from St. Louis to Sydney?

Use this chart to determine the optimal time to book a return flight from St. Louis to Sydney. Price data was last updated on 26 September 2025.

To ensure you get the cheapest price possible for a flight from St. Louis to Sydney, you should look to book at least 57 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, May is the cheapest month in which you can book a flight from St. Louis to Sydney (average of $129). Flying from St. Louis 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.

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 21h 21m. Air New Zealand provides one of the quickest options available for as low as $1,953. 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, May is the cheapest month in which you can book a flight from St. Louis to Sydney (average of $129). Flying from St. Louis 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.

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
Manly
Terrigal
Randwick
Bondi Beach
Coogee
Cronulla
Leura
Lithgow

Browse thousands of different options on Cheapflights for your next trip

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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

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How does Cheapflights help users find flights from St. Louis to Sydney?

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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.

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