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Cheap flights from St. Louis to Sydney from $1,653

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 5/11. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SYD
18 Jun — 25 Jun1
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 13 June 2025.

Round-trip from

$1,653

Popular in

December

Cheapest in

August

Average price

$2,277
Qantas Airways
  • Qantas Airways
  • 5/11-23/11
  • 3 total stops
  • 62h 24m total
  • St. Louis to Sydney
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Highest demand for flights based on searches. 5% potential increase in price ($204 potential increase over avg. return price).
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Cheapest flight prices on average. 2% potential price decrease ($80 potential savings vs. average return price).
Search Deals
Average for round-trip flights in June 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 13 June 2025.

Wed 5/1106:15STL - SYD
2 stops43h 35mQantas Airways
Sun 23/1114:20SYD - STL
1 stop18h 49mQantas Airways
Deal found 12/6$1,653
Wed 29/1013:35STL - SYD
2 stops27h 00mMultiple Airlines
Sat 15/1111:20SYD - STL
2 stops45h 06mMultiple Airlines
Deal found 12/6$1,796
Sun 14/913:39STL - SYD
2 stops26h 41mAir Canada
Sat 27/909:20SYD - STL
2 stops29h 38mAir Canada
Deal found 12/6$1,825
Sun 14/919:43STL - SYD
1 stop20h 12mAmerican Airlines
Sat 27/909:10SYD - STL
2 stops23h 50mAmerican Airlines
Deal found 12/6$1,933
Tue 29/718:15STL - SYD
2 stops25h 20mAir New Zealand
Tue 12/808:45SYD - STL
2 stops47h 00mAir New Zealand
Deal found 12/6$2,020
Wed 11/608:25STL - SYD
2 stops31h 35mUnited Airlines
Sat 21/610:20SYD - STL
1 stop22h 40mUnited Airlines
Deal found 10/6$2,094
Thu 24/706:00STL - SYD
2 stops33h 35mDelta
Tue 5/809:25SYD - STL
2 stops29h 28mDelta
Deal found 12/6$2,095
Sat 12/717:23STL - SYD
2 stops32h 52mLATAM Airlines
Sat 19/711:50SYD - STL
3 stops35h 32mLATAM Airlines
Deal found 12/6$5,373
Fri 11/708:00STL - SYD
3 stops44h 00mTurkish Airlines
Fri 18/720:55SYD - STL
3 stops40h 50mTurkish Airlines
Deal found 12/6$5,619
Fri 27/608:35STL - SYD
2 stops35h 15mCathay Pacific
Sat 26/707:40SYD - STL
2 stops30h 17mCathay Pacific
Deal found 13/6$6,061

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 13 June 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

Wed 5/11

06:15-18:50

2 stops43h 35m

Sydney Kingsford Smith

Sun 23/11

14:20-16:09

1 stop18h 49m

$1,653

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 29/10

13:35-08:35

2 stops27h 00m

Sydney Kingsford Smith

Sat 15/11

11:20-15:26

2 stops45h 06m

$1,796

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 14/9

13:39-07:20

2 stops26h 41m

Sydney Kingsford Smith

Sat 27/9

09:20-23:58

2 stops29h 38m

$1,825

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 14/9

19:43-06:55

1 stop20h 12m

Sydney Kingsford Smith

Sat 27/9

09:10-18:00

2 stops23h 50m

$1,933

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 29/7

18:15-10:35

2 stops25h 20m

Sydney Kingsford Smith

Tue 12/8

08:45-16:45

2 stops47h 00m

$2,020

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 24/7

06:00-06:35

2 stops33h 35m

Sydney Kingsford Smith

Tue 5/8

09:25-23:53

2 stops29h 28m

$2,095

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 13/8

17:41-06:55

1 stop22h 14m

Sydney Kingsford Smith

Mon 18/8

10:20-16:45

1 stop21h 25m

$2,200

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 12/7

17:23-17:15

2 stops32h 52m

Sydney Kingsford Smith

Sat 19/7

11:50-08:22

3 stops35h 32m

$5,373

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 11/7

08:00-19:00

3 stops44h 00m

Sydney Kingsford Smith

Fri 18/7

20:55-22:45

3 stops40h 50m

$5,619

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 27/6

08:35-10:50

2 stops35h 15m

Sydney Kingsford Smith

Sat 26/7

07:40-22:57

2 stops30h 17m

$6,061

Flights are sorted by cheapest return flights first.

Deals found on 12/6

Showing 1-10 of 11 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

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 9 June 2025.

To ensure you get the cheapest price possible for a flight from St. Louis to Sydney, you should look to book at least 83 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.

Rainfall in Sydney by month

Plan your trip to Sydney by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Sydney ranges from 50.0 - 130.0 inches per month. March is typically the wettest month, when rainfall can reach 130.0 mm. September is typically the driest time to visit Sydney when rainfall is around 50.0 mm.

Temperature in Sydney by month

Plan your trip to Sydney by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Sydney, use this chart to help with planning. For those seeking warmer temperatures, January is the ideal time of year to visit, when temperatures reach an average of 22.0 C. Travellers hoping to avoid the cold should look outside of July, when temperatures are typically at their lowest (around 11.0 C).

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 13 June 2025.
To help decide which airline to fly from St. Louis to Sydney, see what other customers have to say about Alaska Airlines, Delta and Air New Zealand. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very Good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Surinder,May 2025

SEA - YYZ

My wife wanted the aile seat and I always prefer window seat. Luckily we both got the best seats we wanted. The plane was very nice and we enjoyed the best take off and the smooth landing at Toronto. All the services by the staff inside the aeroplane were very nice well appreciated. Thanks again and hope to see you soon.
Alaska Airlines
8.0
Very Good
10,000 reviews
Alaska Airlines
8.0
Very Good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Surinder,May 2025

SEA - YYZ

My wife wanted the aile seat and I always prefer window seat. Luckily we both got the best seats we wanted. The plane was very nice and we enjoyed the best take off and the smooth landing at Toronto. All the services by the staff inside the aeroplane were very nice well appreciated. Thanks again and hope to see you soon.
Delta
8.0
Very Good
7,950 reviews
Alaska Airlines
8.0
Very Good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Surinder,May 2025

SEA - YYZ

My wife wanted the aile seat and I always prefer window seat. Luckily we both got the best seats we wanted. The plane was very nice and we enjoyed the best take off and the smooth landing at Toronto. All the services by the staff inside the aeroplane were very nice well appreciated. Thanks again and hope to see you soon.
Air New Zealand
8.0
Very Good
483 reviews
Alaska Airlines
8.0
Very Good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Surinder,May 2025

SEA - YYZ

My wife wanted the aile seat and I always prefer window seat. Luckily we both got the best seats we wanted. The plane was very nice and we enjoyed the best take off and the smooth landing at Toronto. All the services by the staff inside the aeroplane were very nice well appreciated. Thanks again and hope to see you soon.
Qantas Airways
7.5
Good
854 reviews
Alaska Airlines
8.0
Very Good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Surinder,May 2025

SEA - YYZ

My wife wanted the aile seat and I always prefer window seat. Luckily we both got the best seats we wanted. The plane was very nice and we enjoyed the best take off and the smooth landing at Toronto. All the services by the staff inside the aeroplane were very nice well appreciated. Thanks again and hope to see you soon.
LATAM Airlines
7.5
Good
1,785 reviews
Alaska Airlines
8.0
Very Good
10,000 reviews
Check prices

Overall

8.0

Entertainment

7.1

Food

7.1

Boarding

8.1

Comfort

7.8

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Surinder,May 2025

SEA - YYZ

My wife wanted the aile seat and I always prefer window seat. Luckily we both got the best seats we wanted. The plane was very nice and we enjoyed the best take off and the smooth landing at Toronto. All the services by the staff inside the aeroplane were very nice well appreciated. Thanks again and hope to see you soon.

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.

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

    Our cheapest airline available from St. Louis to Sydney is Qantas Airways. Our recent data shows that you can find tickets from as low as $1,653 on this airline. Additional options worth looking into are Air Canada and American Airlines, starting at $1,825 and $1,933 round-trip. Qantas Airways is 27% cheaper than the average price of flights available within the next 90 days to this destination.

  • 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 St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Parramatta
Wollongong
Katoomba
Manly
Penrith
Coogee
Randwick
Cronulla
Terrigal
Lithgow
Bondi Beach
Leura
Swansea

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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

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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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