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$745+ 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 7/2. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SYD
May 6 — May 131
Tue 5/6
Tue 5/13
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to Sydney Kingsford Smith are usually found in November or August, booked 83 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 May 1, 2025.

Most accurate provider

AranGrant
3 stars

Most trusted provider

AranGrant
3 stars

Round-trip from

$1,255
(StudentUniverse)

One-way from

$745
(Delta)

Popular in

December

Cheapest in

November

Average price

$1,468
Provider with most accurate pricing for Lambert-St Louis-Sydney Kingsford Smith flight deals.
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Provider most trusted by Cheapflights users for Lambert-St Louis-Sydney Kingsford Smith flights.
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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. 8% potential increase in price ($133 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($29 potential savings vs. average RT price).
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Average for round-trip flights in May 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 May 1, 2025.

This StudentUniverse deal was found by Cheapflights users on 4/28. 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 StudentUniverse is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/97:47 pmSTL - SYD
1 stop20h 08mQantas Airways
Fri 6/209:10 amSYD - STL
1 stop28h 49mQantas Airways
Deal found 4/28$1,255
This Gurufare deal was found by Cheapflights users on 4/28. 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 Gurufare is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/205:49 pmSTL - SYD
2 stops23h 56mAir New Zealand
Wed 9/39:55 amSYD - STL
2 stops27h 21mAir New Zealand
Deal found 4/28$1,261
This American Airlines deal was found by Cheapflights users on 4/29. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/241:21 pmSTL - SYD
2 stops25h 44mAmerican Airlines
Tue 7/85:45 pmSYD - STL
1 stop20h 36mAmerican Airlines
Deal found 4/29$1,328
This Jetabroad deal was found by Cheapflights users on 4/30. 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.
Sat 8/163:24 pmSTL - SYD
2 stops32h 16mMultiple Airlines
Sat 8/301:45 pmSYD - STL
2 stops24h 29mMultiple Airlines
Deal found 4/30$1,343
This Air Canada deal was found by Cheapflights users on 4/28. 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.
Thu 6/57:30 amSTL - SYD
2 stops32h 50mAir Canada
Thu 6/129:20 amSYD - STL
2 stops42h 16mAir Canada
Deal found 4/28$1,346
This United Airlines deal was found by Cheapflights users on 4/28. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/91:42 pmSTL - SYD
2 stops26h 13mUnited Airlines
Fri 6/2010:20 amSYD - STL
1 stop22h 40mUnited Airlines
Deal found 4/28$1,357
This oojo deal was found by Cheapflights users on 4/30. 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.
Thu 8/145:32 pmSTL - SYD
2 stops27h 43mFiji Airways
Mon 8/181:15 pmSYD - STL
2 stops24h 42mFiji Airways
Deal found 4/30$1,370
This Delta deal was found by Cheapflights users on 4/28. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/99:28 amSTL - SYD
2 stops30h 07mDelta
Mon 6/239:25 amSYD - STL
2 stops27h 09mDelta
Deal found 4/28$1,371
This Alaska Airlines deal was found by Cheapflights users on 4/28. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/293:08 pmSTL - SYD
2 stops61h 37mAlaska Airlines
Tue 5/69:40 pmSYD - STL
2 stops41h 19mAlaska Airlines
Deal found 4/28$1,594
This oojo deal was found by Cheapflights users on 4/28. 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.
Thu 5/12:19 pmSTL - SYD
2 stops35h 51mQatar Airways
Sat 5/38:45 pmSYD - STL
2 stops40h 29mQatar Airways
Deal found 4/28$2,194
This AranGrant deal was found by Cheapflights users on 4/30. 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 AranGrant is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/1410:31 amSTL - SYD
2 stops33h 19mCathay Pacific
Mon 6/27:40 amSYD - STL
2 stops30h 05mCathay Pacific
Deal found 4/30$3,516
This Flightnetwork deal was found by Cheapflights users on 4/28. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/98:10 amSTL - SYD
3 stops43h 50mTurkish Airlines
Fri 6/208:55 pmSYD - STL
3 stops40h 50mTurkish Airlines
Deal found 4/28$3,948

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 May 1, 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

Mon 6/9

7:47 pm-6:55 am

1 stop20h 08m

Sydney Kingsford Smith

Fri 6/20

9:10 am-10:59 pm

1 stop28h 49m

$1,255

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 6/24

1:21 pm-6:05 am

2 stops25h 44m

Sydney Kingsford Smith

Tue 7/8

5:45 pm-11:21 pm

1 stop20h 36m

$1,328

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 6/5

7:30 am-7:20 am

2 stops32h 50m

Sydney Kingsford Smith

Thu 6/12

9:20 am-12:36 pm

2 stops42h 16m

$1,346

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 6/9

1:42 pm-6:55 am

2 stops26h 13m

Sydney Kingsford Smith

Fri 6/20

10:20 am-6:00 pm

1 stop22h 40m

$1,357

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 6/9

9:28 am-6:35 am

2 stops30h 07m

Sydney Kingsford Smith

Mon 6/23

9:25 am-9:34 pm

2 stops27h 09m

$1,371

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 6/5

4:32 pm-7:20 am

2 stops23h 48m

Sydney Kingsford Smith

Thu 6/12

9:10 am-10:59 pm

1 stop28h 49m

$1,426

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 5/14

6:30 am-7:45 pm

2 stops46h 15m

Sydney Kingsford Smith

Sat 5/17

9:40 pm-2:07 pm

2 stops31h 27m

$1,669

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 5/16

11:00 am-10:35 am

2 stops32h 35m

Sydney Kingsford Smith

Mon 5/26

10:20 am-6:00 pm

1 stop22h 40m

$1,786

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 5/14

10:31 am-10:50 am

2 stops33h 19m

Sydney Kingsford Smith

Mon 6/2

7:40 am-10:45 pm

2 stops30h 05m

$3,516

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 6/9

8:10 am-7:00 pm

3 stops43h 50m

Sydney Kingsford Smith

Fri 6/20

8:55 pm-10:45 pm

3 stops40h 50m

$3,948

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/30

Showing 1-10 of 16 results
1
2

Compare providers for flights from St. Louis to Sydney

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Sydney in May.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on St. Louis-Sydney flights, users find the pricing of AranGrant to be most consistent on Cheapflights vs. AranGrant Users can find the same prices on St. Louis-Sydney flight deals on Cheapflights vs. AranGrant >95% of the time. Price accuracy is based on data collected from St. Louis-Sydney flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on St. Louis-Sydney flights, Cheapflights users trust AranGrant the most. AranGrant has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Sydney flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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 April 25, 2025.

The best time to book flights from St. Louis to Sydney is 83 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, March is the cheapest month in which you can book a flight from St. Louis to Sydney (average of $1,043). Flying from St. Louis to Sydney in December is currently the most expensive (average of $1,643). 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 May 1, 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.

What is the cheapest day to fly from St. Louis to Sydney?

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Sydney. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their St. Louis to Sydney flight should consider departing on Monday mornings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

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 2.0 - 5.1 inches per month. March is typically the wettest month, when rainfall can reach 5.1 in. September is typically the driest time to visit Sydney when rainfall is around 2.0 in.

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 71.6 F. Travelers looking to avoid the cold should look outside of July, when temperatures are typically at their lowest (around 51.8 F).

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 May 1, 2025.
ANA
8.3
Very good
852 reviews

Comfort

8.1

Boarding

8.5

Entertainment

7.9

Food

7.6

Crew

8.7

Overall

8.3

Reviews

1 / 20
4.0
Okay

Anonymous,Mar 2025

SFO - HND

Don't bother with economy, it's so small!!! I'm a small person and I was cramped in the middle seat on a 11 hour flight. Not fun. Go for business or first class for such a long flight if you can or be prepared to have trouble moving when you stand up. Also be prepared to have trouble sleeping too. Crew was awesome though, they were helpful and provided excellent service.
ANA
8.3
Very good
852 reviews
ANA
8.3
Very good
852 reviews

Comfort

8.1

Boarding

8.5

Entertainment

7.9

Food

7.6

Crew

8.7

Overall

8.3

Reviews

1 / 20
4.0
Okay

Anonymous,Mar 2025

SFO - HND

Don't bother with economy, it's so small!!! I'm a small person and I was cramped in the middle seat on a 11 hour flight. Not fun. Go for business or first class for such a long flight if you can or be prepared to have trouble moving when you stand up. Also be prepared to have trouble sleeping too. Crew was awesome though, they were helpful and provided excellent service.
Alaska Airlines
8.0
Very good
9,972 reviews
ANA
8.3
Very good
852 reviews

Comfort

8.1

Boarding

8.5

Entertainment

7.9

Food

7.6

Crew

8.7

Overall

8.3

Reviews

1 / 20
4.0
Okay

Anonymous,Mar 2025

SFO - HND

Don't bother with economy, it's so small!!! I'm a small person and I was cramped in the middle seat on a 11 hour flight. Not fun. Go for business or first class for such a long flight if you can or be prepared to have trouble moving when you stand up. Also be prepared to have trouble sleeping too. Crew was awesome though, they were helpful and provided excellent service.
Delta
8.0
Very good
7,934 reviews
ANA
8.3
Very good
852 reviews

Comfort

8.1

Boarding

8.5

Entertainment

7.9

Food

7.6

Crew

8.7

Overall

8.3

Reviews

1 / 20
4.0
Okay

Anonymous,Mar 2025

SFO - HND

Don't bother with economy, it's so small!!! I'm a small person and I was cramped in the middle seat on a 11 hour flight. Not fun. Go for business or first class for such a long flight if you can or be prepared to have trouble moving when you stand up. Also be prepared to have trouble sleeping too. Crew was awesome though, they were helpful and provided excellent service.
Air New Zealand
8.0
Very good
472 reviews
ANA
8.3
Very good
852 reviews

Comfort

8.1

Boarding

8.5

Entertainment

7.9

Food

7.6

Crew

8.7

Overall

8.3

Reviews

1 / 20
4.0
Okay

Anonymous,Mar 2025

SFO - HND

Don't bother with economy, it's so small!!! I'm a small person and I was cramped in the middle seat on a 11 hour flight. Not fun. Go for business or first class for such a long flight if you can or be prepared to have trouble moving when you stand up. Also be prepared to have trouble sleeping too. Crew was awesome though, they were helpful and provided excellent service.
Qantas Airways
7.5
Good
829 reviews
ANA
8.3
Very good
852 reviews

Comfort

8.1

Boarding

8.5

Entertainment

7.9

Food

7.6

Crew

8.7

Overall

8.3

Reviews

1 / 20
4.0
Okay

Anonymous,Mar 2025

SFO - HND

Don't bother with economy, it's so small!!! I'm a small person and I was cramped in the middle seat on a 11 hour flight. Not fun. Go for business or first class for such a long flight if you can or be prepared to have trouble moving when you stand up. Also be prepared to have trouble sleeping too. Crew was awesome though, they were helpful and provided excellent service.

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?

    According to our current data, Qantas Airways ($1,255), American Airlines ($1,328), and Air Canada ($1,346) offers the cheapest pricing from St. Louis to Sydney. Qantas Airways is priced at 17% 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, March is the cheapest month in which you can book a flight from St. Louis to Sydney (average of $1,043). Flying from St. Louis to Sydney in December is currently the most expensive (average of $1,643). 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 St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Wollongong
Parramatta
Coogee
Manly

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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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Springfield to Coolangatta flights

Top 5 airlines flying from St. Louis to Sydney

Discover the top 5 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 May 1, 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$962Average$1,339FlexibilityNo cancel feeOn-time67%
Air New ZealandCheapest$1,173Average$1,875FlexibilityNo cancel feeOn-time78%
American AirlinesCheapest$1,193Average$1,444FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$1,204Average$1,476FlexibilityNo cancel feeOn-time69%
Qantas AirwaysCheapest$1,281Average$1,681FlexibilityNo cancel feeOn-time74%

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