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Cheap flights from St. Louis to Sydney from $870

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 15/9. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SYD
1 May — 8 May1
1 adult
1 adult, Economy, 0 bags

Cheap 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 1 April 2026.

Wed 23/912:10
STL
-
SYD
2 stops28h 10m
Air Canada
Wed 7/1010:20
SYD
-
STL
2 stops48h 21m
Air Canada
Deal found 30/3$1,661
Tue 13/1008:55
STL
-
SYD
2 stops31h 25m
Air Canada
Fri 13/1111:20
SYD
-
STL
2 stops45h 10m
Air Canada
Deal found 1/4$1,674
Sat 7/1116:15
STL
-
SYD
2 stops48h 20m
Air Canada
Sat 14/1111:20
SYD
-
STL
2 stops45h 10m
Air Canada
Deal found 30/3$1,675
Tue 13/1016:30
STL
-
SYD
2 stops23h 50m
Air Canada
Wed 18/1111:20
SYD
-
STL
2 stops45h 10m
Air Canada
Deal found 31/3$1,684
Sun 4/1005:20
STL
-
SYD
2 stops35h 00m
Air Canada
Sun 18/1010:20
SYD
-
STL
2 stops29h 23m
Air Canada
Deal found 29/3$1,687
Mon 7/905:10
STL
-
SYD
2 stops35h 10m
Air Canada
Mon 14/909:20
SYD
-
STL
2 stops29h 30m
Air Canada
Deal found 30/3$1,698
Tue 12/518:11
STL
-
SYD
2 stops26h 39m
Fiji Airways
Tue 19/513:15
SYD
-
STL
2 stops24h 44m
Fiji Airways
Deal found 28/3$1,743
Tue 1/912:10
STL
-
SYD
2 stops28h 10m
Air Canada
Tue 8/909:20
SYD
-
STL
3 stops48h 21m
Air Canada
Deal found 30/3$1,782
Mon 6/716:48
STL
-
SYD
2 stops23h 32m
Air Canada
Fri 17/709:20
SYD
-
STL
2 stops43h 42m
Air Canada
Deal found 29/3$1,792
Sat 4/714:40
STL
-
SYD
2 stops25h 40m
Air Canada
Fri 17/709:20
SYD
-
STL
2 stops43h 42m
Air Canada
Deal found 29/3$1,798

Find 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 1 April 2026.

Round-trip from

$1,661

One-way from

$703

Popular in

December

Cheapest in

March

Average price

$2,037
Air Canada
  • Air Canada
  • 23/9-7/10
  • 4 total stops
  • 76h 31m total
  • St. Louis to Sydney
Search Deals
26/4
  • 26/4
  • 3 total stops
  • 46h 55m total
  • St. Louis to Sydney
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($166 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($48 potential savings vs. average return price).
Search Deals
Average for round-trip flights in April 2026
Search Deals

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 1 April 2026.
Use the filters below to find and compare flights from St. Louis to Sydney that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight
Fastest return journey

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 4/5

19:06-06:55

1 stop20h 49m

Sydney Kingsford Smith

Mon 18/5

10:20-18:22

1 stop23h 02m

$2,143

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 13/5

16:44-07:00

2 stops23h 16m

Sydney Kingsford Smith

Wed 20/5

10:20-18:22

1 stop23h 02m

$2,144

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 26/4

06:21-07:05

1 stop33h 44m

Sydney Kingsford Smith

Sun 3/5

12:00-17:21

1 stop20h 21m

$2,261

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 6/7

06:01-06:55

2 stops33h 54m

Sydney Kingsford Smith

Fri 17/7

10:20-18:17

1 stop22h 57m

$2,317

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 23/4

06:21-07:05

1 stop33h 44m

Sydney Kingsford Smith

Sat 2/5

17:50-23:57

1 stop21h 07m

$2,407

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 29/5

19:23-06:55

1 stop20h 32m

Sydney Kingsford Smith

Sat 20/6

09:30-20:57

2 stops26h 27m

$2,417

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 20/4

06:21-07:05

1 stop33h 44m

Sydney Kingsford Smith

Mon 27/4

17:50-23:57

1 stop21h 07m

$2,477
Cheapest one-way

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 15/9

06:00-11:50

3 stops38h 50m

$870
Fastest single journey

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 15/9

12:10-07:20

2 stops28h 10m

$945

Flights are sorted by cheapest return flights first.

Deals found on 30/3

Sorted by cheapest first

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 $936). Flying from St. Louis to Sydney in June is currently the most expensive (average of $1,848). 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 49m. United Airlines provides one of the quickest options available for as low as $2,143. 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 $936). Flying from St. Louis to Sydney in June is currently the most expensive (average of $1,848). 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
Penrith
Terrigal
Katoomba
Lithgow
Manly
Bondi Beach
Coogee
Cronulla
Leura
Randwick

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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