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Cheap flights from St. Louis to Sydney from $810

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 31/10. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SYD
21 Aug — 28 Aug1
1 adult

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 16 August 2025.

Round-trip from

$1,678

One-way from

$810

Popular in

December

Cheapest in

August

Average price

$1,931
Qantas Airways
  • Qantas Airways
  • 28/11-14/12
  • 3 total stops
  • 47h 35m total
  • St. Louis to Sydney
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31/10
  • 31/10
  • 2 total stops
  • 34h 00m total
  • St. Louis to Sydney
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Highest demand for flights based on searches. 5% potential increase in price ($216 potential increase over avg. return price).
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Cheapest flight prices on average. 2% potential price decrease ($82 potential savings vs. average return price).
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Average for round-trip flights in August 2025
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Find flight deals from St. Louis to Sydney

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 16 August 2025.

Fri 28/1116:07STL - SYD
1 stop21h 48mQantas Airways
Sun 14/1207:20SYD - STL
2 stops27h 55mQantas Airways
Deal found 15/8$1,678
Tue 4/1115:59STL - SYD
1 stop21h 56mQantas Airways
Tue 11/1117:30SYD - STL
2 stops23h 12mQantas Airways
Deal found 14/8$1,696
Wed 5/1107:00STL - SYD
2 stops33h 20mQantas Airways
Sun 23/1114:20SYD - STL
1 stop19h 20mQantas Airways
Deal found 15/8$1,699
Fri 28/1116:35STL - SYD
2 stops24h 55mAir New Zealand
Sun 14/1211:45SYD - STL
2 stops27h 13mAir New Zealand
Deal found 15/8$1,752
Tue 4/1117:58STL - SYD
2 stops25h 32mFiji Airways
Tue 11/1114:10SYD - STL
2 stops22h 20mFiji Airways
Deal found 14/8$1,755
Wed 29/1006:39STL - SYD
1 stop34h 21mQantas Airways
Sat 15/1119:15SYD - STL
2 stops38h 53mQantas Airways
Deal found 15/8$1,793
Mon 27/1016:05STL - SYD
2 stops48h 30mAir Canada
Mon 10/1111:20SYD - STL
2 stops45h 09mAir Canada
Deal found 14/8$1,819
Sat 23/813:30STL - SYD
2 stops50h 50mAir Canada
Sat 6/909:20SYD - STL
2 stops25h 37mAir Canada
Deal found 15/8$1,833
Sat 8/1116:05STL - SYD
2 stops48h 30mAir Canada
Fri 21/1111:20SYD - STL
2 stops45h 09mAir Canada
Deal found 14/8$1,835
Fri 31/1013:35STL - SYD
2 stops27h 00mAir Canada
Sat 8/1111:20SYD - STL
2 stops45h 09mAir Canada
Deal found 15/8$1,850
Wed 29/1016:05STL - SYD
2 stops48h 30mAir Canada
Sat 15/1111:20SYD - STL
2 stops45h 09mAir Canada
Deal found 14/8$1,851

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 16 August 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 28/11

13:55-06:55

1 stop24h 00m

Sydney Kingsford Smith

Sun 14/12

06:05-16:07

2 stops27h 02m

$1,678

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 4/11

15:59-06:55

1 stop21h 56m

Sydney Kingsford Smith

Tue 11/11

17:30-23:42

2 stops23h 12m

$1,696

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 5/11

07:00-09:20

2 stops33h 20m

Sydney Kingsford Smith

Sun 23/11

14:20-19:30

1 stop22h 10m

$1,699

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 8/11

07:00-10:55

2 stops34h 55m

Sydney Kingsford Smith

Fri 21/11

14:20-16:40

1 stop19h 20m

$1,699

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 15/1

13:48-06:55

1 stop24h 07m

Sydney Kingsford Smith

Sat 24/1

13:00-23:59

2 stops27h 59m

$1,713

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 28/11

16:35-10:30

2 stops24h 55m

Sydney Kingsford Smith

Sun 14/12

11:45-21:58

2 stops27h 13m

$1,752

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 4/11

17:58-12:30

2 stops25h 32m

Sydney Kingsford Smith

Tue 11/11

14:10-19:30

2 stops22h 20m

$1,755

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

$1,793

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 27/10

16:05-08:35

2 stops48h 30m

Sydney Kingsford Smith

Mon 10/11

11:20-15:29

2 stops45h 09m

$1,819

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 31/10

07:00-09:00

2 stops34h 00m

$810

Flights are sorted by cheapest return flights first.

Deals found on 16/8

Showing 1-10 of 17 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 8 August 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.

What’s the top stopover airport for flights from St. Louis to Sydney?

Share of one-stop return flights from St. Louis to Sydney chosen by Cheapflights users in the past 12 months, using the same stopover each way.

Dallas (DFW) – chosen by Cheapflights users on 60% of one-stop itineraries from St. Louis to Sydney on Cheapflights.

What’s the cheapest stopover airport for flights from St. Louis to Sydney?

Average return fare for one-stop flights from St. Louis to Sydney, chosen by Cheapflights users in the past 12 months, with the same stopover each way.

Dallas (DFW) is the most affordable one-stop option, with an average return flight price of $1,896.

What’s the fastest stopover option from St. Louis to Sydney?

Shortest average travel time for one-stop one-way flights from St. Louis to Sydney, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.

Flights via Dallas (DFW) have the shortest average one-way travel time for one-stop routes: 21h 32m.

Which airport typically offers the quickest stopover for flights from St. Louis to Sydney?

Average stopover duration for one-stop one-way flights from St. Louis to Sydney, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Dallas (DFW) offer the fastest connection on this route, with an average stopover time of 3h 20m.

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.

  • 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
Coogee
Manly
Terrigal
Cronulla
Lithgow
Bondi Beach
Randwick
Leura

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Alternative routes for St. Louis to Sydney

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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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