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$1,077+ Cheap flights from St. Louis (STL) to Sydney (SYD)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/28. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SYD
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
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 May, booked 85 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 June 12, 2025.

Round-trip from

$1,270
(KAYAK)

Popular in

December

Cheapest in

August

Average price

$1,483
From Lambert-St Louis to Sydney Kingsford Smith
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Highest demand for flights based on searches. 5% potential increase in price ($87 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($34 potential savings vs. average RT price).
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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 June 12, 2025.

This oojo deal was found by Cheapflights users on 6/12. 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.
Fri 11/286:15 amSTL - SYD
2 stops47h 10mQantas Airways
Sun 12/142:20 pmSYD - STL
1 stop18h 47mQantas Airways
Deal found 6/12$1,077
This Air Canada deal was found by Cheapflights users on 6/9. 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.
Sun 9/141:30 pmSTL - SYD
2 stops26h 50mMultiple Airlines
Sat 9/279:20 amSYD - STL
2 stops22h 12mMultiple Airlines
Deal found 6/9$1,169
This FlightHub deal was found by Cheapflights users on 6/11. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/141:39 pmSTL - SYD
2 stops26h 41mAir Canada
Sat 9/279:20 amSYD - STL
2 stops29h 38mAir Canada
Deal found 6/11$1,189
This American Airlines deal was found by Cheapflights users on 6/11. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/144:02 pmSTL - SYD
1 stop23h 53mAmerican Airlines
Sat 9/279:10 amSYD - STL
2 stops23h 50mAmerican Airlines
Deal found 6/11$1,259
This oojo deal was found by Cheapflights users on 6/12. 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.
Tue 7/296:15 pmSTL - SYD
2 stops25h 20mAir New Zealand
Tue 8/128:45 amSYD - STL
2 stops47h 00mAir New Zealand
Deal found 6/12$1,316
This United Airlines deal was found by Cheapflights users on 6/10. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/118:25 amSTL - SYD
2 stops31h 35mUnited Airlines
Sat 6/2110:20 amSYD - STL
1 stop22h 40mUnited Airlines
Deal found 6/10$1,364
This Delta deal was found by Cheapflights users on 6/11. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/269:28 amSTL - SYD
2 stops30h 07mDelta
Mon 7/79:25 amSYD - STL
2 stops30h 13mDelta
Deal found 6/11$1,369
This KAYAK deal was found by Cheapflights users on 6/12. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/125:23 pmSTL - SYD
2 stops32h 52mLATAM Airlines
Sat 7/1911:50 amSYD - STL
3 stops35h 32mLATAM Airlines
Deal found 6/12$3,500
This Booking.com deal was found by Cheapflights users on 6/11. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/33:23 pmSTL - SYD
3 stops36h 37mTurkish Airlines
Fri 10/179:55 pmSYD - STL
3 stops57h 49mTurkish Airlines
Deal found 6/11$3,687
This oojo deal was found by Cheapflights users on 6/10. 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.
Fri 6/276:28 amSTL - SYD
2 stops37h 22mCathay Pacific
Sat 7/267:40 amSYD - STL
2 stops30h 17mCathay Pacific
Deal found 6/10$3,965

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 June 12, 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

Tue 7/29

5:27 pm-6:55 am

1 stop22h 28m

Sydney Kingsford Smith

Tue 8/12

9:10 am-11:09 pm

1 stop28h 59m

$1,270

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 7/29

6:15 pm-10:35 am

2 stops25h 20m

Sydney Kingsford Smith

Tue 8/12

8:45 am-4:45 pm

2 stops47h 00m

$1,316

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 7/29

1:17 pm-7:05 am

2 stops26h 48m

Sydney Kingsford Smith

Tue 8/12

9:10 am-11:09 pm

1 stop28h 59m

$1,348

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 7/15

7:45 am-6:35 am

2 stops31h 50m

Sydney Kingsford Smith

Wed 7/30

9:25 am-6:47 pm

2 stops24h 22m

$1,365

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 8/13

1:30 pm-7:20 am

2 stops26h 50m

Sydney Kingsford Smith

Mon 8/18

5:45 pm-11:09 pm

1 stop20h 24m

$1,397

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 8/13

5:41 pm-6:55 am

1 stop22h 14m

Sydney Kingsford Smith

Mon 8/18

10:20 am-4:45 pm

1 stop21h 25m

$1,433

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 6/20

1:30 pm-7:20 am

3 stops50h 50m

Sydney Kingsford Smith

Fri 7/11

9:20 am-8:50 pm

2 stops26h 30m

$1,590

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 7/12

5:23 pm-5:15 pm

2 stops32h 52m

Sydney Kingsford Smith

Sat 7/19

11:50 am-8:22 am

3 stops35h 32m

$3,500

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 6/27

6:28 am-10:50 am

2 stops37h 22m

Sydney Kingsford Smith

Sat 7/26

7:40 am-10:57 pm

2 stops30h 17m

$3,965

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 6/18

8:10 am-7:00 pm

3 stops43h 50m

Sydney Kingsford Smith

Wed 6/25

8:55 pm-10:45 pm

3 stops40h 50m

$4,379

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/12

Showing 1-10 of 11 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 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 June 9, 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 $1,041). Flying from St. Louis to Sydney in December is currently the most expensive (average of $1,635). 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 June 12, 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.

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 June 12, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Delta and Air New Zealand from St. Louis to Sydney by reading reviews from past customers. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

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

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

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

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

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

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?

    According to our current data, Qantas Airways ($1,270), Air New Zealand ($1,316), and American Airlines ($1,348) offers the cheapest pricing from St. Louis to Sydney. Qantas Airways is priced at 13% 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 $1,041). Flying from St. Louis to Sydney in December is currently the most expensive (average of $1,635). 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
Manly
Coogee

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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 June 12, 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$1,446FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$1,204Average$1,494FlexibilityNo cancel feeOn-time69%
Fiji AirwaysCheapest$1,206Average$1,403FlexibilityNo cancel feeOn-time74%
Qantas AirwaysCheapest$1,260Average$1,556FlexibilityNo cancel feeOn-time74%

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