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$573+ Cheap flights from St. Louis (STL) to Sydney (SYD)

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 9/23. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SYD
oct. 11 — oct. 181
sáb. 10/11
sáb. 10/18
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to Sydney Kingsford Smith are usually found in August or October, booked 57 days in advance, depart on a Wednesday or Tuesday and return on a Wednesday

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 septiembre 11, 2025.

Round-trip from

$1,103
(oojo)

One-way from

$573
(Kiwi.com)

Popular in

December

Cheapest in

August

Average price

$1,516
From Lambert-St Louis to Sydney Kingsford Smith
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One-way flight from Lambert-St Louis to Sydney Kingsford Smith
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Highest demand for flights based on searches. 6% potential increase in price ($94 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($35 potential savings vs. average RT price).
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Average for round-trip flights in September 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 septiembre 11, 2025.

This oojo deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/57:00 amSTL - SYD
2 stops33h 20mQantas Airways
dom. 11/232:05 pmSYD - STL
1 stop22h 25mQantas Airways
Deal found 9/9$1,102
This oojo deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 11/37:00 amSTL - SYD
2 stops37h 00mQantas Airways
lun. 11/172:05 pmSYD - STL
1 stop22h 25mQantas Airways
Deal found 9/10$1,103
This oojo deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 11/285:50 pmSTL - SYD
2 stops35h 05mQantas Airways
dom. 12/142:05 pmSYD - STL
1 stop20h 00mQantas Airways
Deal found 9/10$1,107
This Jetabroad deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Jetabroad is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 10/243:57 pmSTL - SYD
2 stops35h 48mHawaiian Airlines
vie. 10/319:40 pmSYD - STL
2 stops33h 38mHawaiian Airlines
Deal found 9/9$1,166
This Justfly.com deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/296:39 amSTL - SYD
1 stop34h 21mQantas Airways
sáb. 11/157:15 pmSYD - STL
2 stops34h 24mQantas Airways
Deal found 9/9$1,174
This Air Canada deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/294:05 pmSTL - SYD
2 stops48h 30mAir Canada
sáb. 11/1511:20 amSYD - STL
2 stops45h 09mAir Canada
Deal found 9/9$1,206
This Air Canada deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 10/264:05 pmSTL - SYD
2 stops48h 30mAir Canada
dom. 11/211:20 amSYD - STL
2 stops45h 09mAir Canada
Deal found 9/11$1,207
This Travelocity deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 9/216:20 amSTL - SYD
1 stop33h 45mMultiple Airlines
mar. 9/309:20 amSYD - STL
2 stops44h 58mMultiple Airlines
Deal found 9/9$1,281
This Travelocity deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 11/34:43 pmSTL - SYD
2 stops23h 52mAir Canada
lun. 11/1711:20 amSYD - STL
2 stops45h 09mAir Canada
Deal found 9/10$1,294

Cheapflights Fare Finder

 
Customize 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 2,558,603 searches. Data last updated septiembre 11, 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

vie. 11/28

5:50 pm-10:25 pm

2 stops35h 35m

Sydney Kingsford Smith

dom. 12/14

2:05 pm-7:27 pm

1 stop22h 22m

$1,108

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

mié. 10/29

6:39 am-9:00 am

1 stop34h 21m

Sydney Kingsford Smith

sáb. 11/15

7:15 pm-5:08 pm

2 stops38h 53m

$1,166

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

dom. 10/26

4:05 pm-8:35 am

2 stops48h 30m

Sydney Kingsford Smith

dom. 11/2

11:20 am-4:29 pm

2 stops45h 09m

$1,207

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

mié. 11/5

1:20 pm-6:55 am

1 stop24h 35m

Sydney Kingsford Smith

dom. 11/23

2:05 pm-4:40 pm

1 stop19h 35m

$1,312

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

vie. 11/28

7:00 am-7:25 am

1 stop31h 25m

Sydney Kingsford Smith

dom. 12/14

2:05 pm-7:27 pm

1 stop22h 22m

$1,347

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

dom. 10/26

2:15 pm-9:00 am

2 stops26h 45m

Sydney Kingsford Smith

dom. 11/2

2:05 pm-6:08 pm

1 stop20h 03m

$1,350

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

vie. 10/24

1:40 pm-8:00 am

2 stops26h 20m

Sydney Kingsford Smith

vie. 10/31

10:20 am-5:39 pm

2 stops23h 19m

$1,366

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

mié. 11/5

1:35 pm-8:45 am

3 stops26h 10m

Sydney Kingsford Smith

dom. 11/23

9:55 am-6:47 pm

2 stops25h 52m

$1,417

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

mié. 10/29

1:35 pm-8:45 am

3 stops27h 10m

Sydney Kingsford Smith

sáb. 11/15

9:55 am-9:49 pm

3 stops28h 54m

$1,420

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

mar. 9/23

3:35 pm-2:40 pm

2 stops32h 05m

$573

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/10

Showing 1-10 of 16 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 round-trip 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 round-trip flight from St. Louis to Sydney. Price data was last updated on August 29, 2025.

The best time to book flights from St. Louis to Sydney is 57 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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

Currently, February is the cheapest month in which you can book a flight from St. Louis to Sydney (average of $1,035). Flying from St. Louis to Sydney in December is currently the most expensive (average of $1,626). 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 is the cheapest time of day to fly from STL to SYD?

Find hourly flight availability from St. Louis to Sydney. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated septiembre 11, 2025.

It’s optimal to fly from St. Louis to Sydney in the evening. By choosing this option you can save up to 24% on the cost of your flight, compared to a flight at noon.

Reviews of airlines servicing Sydney

Get insights into the airlines that provide service to Sydney. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Sydney. Reviews last updated septiembre 11, 2025.
Get a feel of what it's like to fly with Fiji Airways, Qantas Airways, and United Airlines from St. Louis to Sydney by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Fiji Airways
8.0
Very good
205 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.4

Food

7.5

Crew

8.5

Comfort

8.0

Reviews

1 / 16
6.0
Good

Christopher,Jun 2025

LAX - NAN

No attempt to make you comfortable. All they care about is how can they pack more people on the plane and how can they charge you for as much as possible. I find it invasive and discriminatory that you weigh my carryon (or any of my naggage frankly). If I physically weighed 15kilos more and my bag weighed under your stupid and arbitrary weight limit I would not be charged... but if I'm a person who is skinny and weighs less, well heaven forbid my bag is 1 kilo heavier than you wish!! $$$ VERY VERY DISCRIMINATORY POLICY!! NEXT TIME I'LL TRY TO EAT MY BAGGAGE SO THAT I CAN TAKE ON AS MUCH WEIGHT AS I WANT! Yeah... sounds ridiculous doesn't it!? No more ridiculous than you charging more for people who bring more baggage weight while letting obese people carry on all the weight they want! It just proves it has absolutely nothing to do with safety, or even your operating costs... Just squeezing as much money out of us as possible!!
Fiji Airways
8.0
Very good
205 reviews
Fiji Airways
8.0
Very good
205 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.4

Food

7.5

Crew

8.5

Comfort

8.0

Reviews

1 / 16
6.0
Good

Christopher,Jun 2025

LAX - NAN

No attempt to make you comfortable. All they care about is how can they pack more people on the plane and how can they charge you for as much as possible. I find it invasive and discriminatory that you weigh my carryon (or any of my naggage frankly). If I physically weighed 15kilos more and my bag weighed under your stupid and arbitrary weight limit I would not be charged... but if I'm a person who is skinny and weighs less, well heaven forbid my bag is 1 kilo heavier than you wish!! $$$ VERY VERY DISCRIMINATORY POLICY!! NEXT TIME I'LL TRY TO EAT MY BAGGAGE SO THAT I CAN TAKE ON AS MUCH WEIGHT AS I WANT! Yeah... sounds ridiculous doesn't it!? No more ridiculous than you charging more for people who bring more baggage weight while letting obese people carry on all the weight they want! It just proves it has absolutely nothing to do with safety, or even your operating costs... Just squeezing as much money out of us as possible!!
Qantas Airways
7.5
Good
905 reviews
Fiji Airways
8.0
Very good
205 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.4

Food

7.5

Crew

8.5

Comfort

8.0

Reviews

1 / 16
6.0
Good

Christopher,Jun 2025

LAX - NAN

No attempt to make you comfortable. All they care about is how can they pack more people on the plane and how can they charge you for as much as possible. I find it invasive and discriminatory that you weigh my carryon (or any of my naggage frankly). If I physically weighed 15kilos more and my bag weighed under your stupid and arbitrary weight limit I would not be charged... but if I'm a person who is skinny and weighs less, well heaven forbid my bag is 1 kilo heavier than you wish!! $$$ VERY VERY DISCRIMINATORY POLICY!! NEXT TIME I'LL TRY TO EAT MY BAGGAGE SO THAT I CAN TAKE ON AS MUCH WEIGHT AS I WANT! Yeah... sounds ridiculous doesn't it!? No more ridiculous than you charging more for people who bring more baggage weight while letting obese people carry on all the weight they want! It just proves it has absolutely nothing to do with safety, or even your operating costs... Just squeezing as much money out of us as possible!!
United Airlines
7.4
Good
8,937 reviews
Fiji Airways
8.0
Very good
205 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.4

Food

7.5

Crew

8.5

Comfort

8.0

Reviews

1 / 16
6.0
Good

Christopher,Jun 2025

LAX - NAN

No attempt to make you comfortable. All they care about is how can they pack more people on the plane and how can they charge you for as much as possible. I find it invasive and discriminatory that you weigh my carryon (or any of my naggage frankly). If I physically weighed 15kilos more and my bag weighed under your stupid and arbitrary weight limit I would not be charged... but if I'm a person who is skinny and weighs less, well heaven forbid my bag is 1 kilo heavier than you wish!! $$$ VERY VERY DISCRIMINATORY POLICY!! NEXT TIME I'LL TRY TO EAT MY BAGGAGE SO THAT I CAN TAKE ON AS MUCH WEIGHT AS I WANT! Yeah... sounds ridiculous doesn't it!? No more ridiculous than you charging more for people who bring more baggage weight while letting obese people carry on all the weight they want! It just proves it has absolutely nothing to do with safety, or even your operating costs... Just squeezing as much money out of us as possible!!
American Airlines
7.2
Good
10,000 reviews
Fiji Airways
8.0
Very good
205 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.4

Food

7.5

Crew

8.5

Comfort

8.0

Reviews

1 / 16
6.0
Good

Christopher,Jun 2025

LAX - NAN

No attempt to make you comfortable. All they care about is how can they pack more people on the plane and how can they charge you for as much as possible. I find it invasive and discriminatory that you weigh my carryon (or any of my naggage frankly). If I physically weighed 15kilos more and my bag weighed under your stupid and arbitrary weight limit I would not be charged... but if I'm a person who is skinny and weighs less, well heaven forbid my bag is 1 kilo heavier than you wish!! $$$ VERY VERY DISCRIMINATORY POLICY!! NEXT TIME I'LL TRY TO EAT MY BAGGAGE SO THAT I CAN TAKE ON AS MUCH WEIGHT AS I WANT! Yeah... sounds ridiculous doesn't it!? No more ridiculous than you charging more for people who bring more baggage weight while letting obese people carry on all the weight they want! It just proves it has absolutely nothing to do with safety, or even your operating costs... Just squeezing as much money out of us as possible!!
Air Canada
7.1
Good
10,000 reviews
Fiji Airways
8.0
Very good
205 reviews

Boarding

8.1

Overall

8.0

Entertainment

7.4

Food

7.5

Crew

8.5

Comfort

8.0

Reviews

1 / 16
6.0
Good

Christopher,Jun 2025

LAX - NAN

No attempt to make you comfortable. All they care about is how can they pack more people on the plane and how can they charge you for as much as possible. I find it invasive and discriminatory that you weigh my carryon (or any of my naggage frankly). If I physically weighed 15kilos more and my bag weighed under your stupid and arbitrary weight limit I would not be charged... but if I'm a person who is skinny and weighs less, well heaven forbid my bag is 1 kilo heavier than you wish!! $$$ VERY VERY DISCRIMINATORY POLICY!! NEXT TIME I'LL TRY TO EAT MY BAGGAGE SO THAT I CAN TAKE ON AS MUCH WEIGHT AS I WANT! Yeah... sounds ridiculous doesn't it!? No more ridiculous than you charging more for people who bring more baggage weight while letting obese people carry on all the weight they want! It just proves it has absolutely nothing to do with safety, or even your operating costs... Just squeezing as much money out of us as possible!!

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?

    There are many flights that can get you from St. Louis to Sydney in 35h 35m. Fly via Qantas Airways or Air Canada to get the fastest option. The distance between St. Louis and Sydney is about 9054 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from St. Louis to Sydney round-trip?

    According to our current data, Fiji Airways ($887), Air Canada ($897), and Air New Zealand ($1,173) offers the cheapest pricing from St. Louis to Sydney. Fiji Airways is priced at 39% lower than the current average price of a flight leaving 3 months from now.

  • 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 vacation 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, February is the cheapest month in which you can book a flight from St. Louis to Sydney (average of $1,035). Flying from St. Louis to Sydney in December is currently the most expensive (average of $1,626). 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

Traveling to a place near Sydney?

Book flights to Sydney if you plan to visit one of these locations
Parramatta
Wollongong
Manly
Coogee

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
Columbia to Sydney flights
Springfield to Coolangatta flights

Top 6 airlines flying from St. Louis to Sydney

Discover the top 6 airlines that operate flights from St. Louis to Sydney. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septiembre 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
Fiji AirwaysCheapest$887Average$1,222FlexibilityNo cancel feeOn-time74%
Air CanadaCheapest$897Average$1,339FlexibilityNo cancel feeOn-time67%
Air New ZealandCheapest$1,173Average$1,873FlexibilityNo cancel feeOn-time78%
Qantas AirwaysCheapest$1,262Average$1,562FlexibilityNo cancel feeOn-time74%
American AirlinesCheapest$1,340Average$1,461FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$1,341Average$1,510FlexibilityNo cancel feeOn-time69%

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