Latest deals
Insights
When to book
FAQs
Reviews
Price Alerts

Cheap flights from St. Louis to Sydney from $516

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Sydney departing on 5/5. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from St. Louis to Sydney

Cheap round-trip flights

Enter your travel dates to find the best prices.
Air Canada Logo
1:05 pm - 7:20 am
STL
-
SYD
27h 15m
2 stops
Air Canada Logo
9:20 am - 12:06 pm
SYD
-
STL
41h 46m
2 stops
$1,156Air Canada
Thu, Jun 11 - Tue, Jun 16
Air Canada Logo
1:05 pm - 7:20 am
STL
-
SYD
51h 15m
3 stops
Air Canada Logo
9:20 am - 12:06 pm
SYD
-
STL
41h 46m
2 stops
$1,164Air Canada
Thu, Jun 11 - Tue, Jun 16
Air Canada Logo
5:10 am - 7:20 am
STL
-
SYD
35h 10m
2 stops
Air Canada Logo
9:20 am - 2:02 pm
SYD
-
STL
43h 42m
2 stops
$1,167Air Canada
Mon, Jul 13 - Sun, Jul 19
Air Canada Logo
5:10 am - 7:20 am
STL
-
SYD
35h 10m
2 stops
Air Canada Logo
9:20 am - 2:00 pm
SYD
-
STL
43h 40m
2 stops
$1,180Air Canada
Mon, Sep 7 - Mon, Sep 14
Asiana Airlines Logo
8:40 am - 7:20 am
STL
-
SYD
31h 40m
1 stop
Asiana Airlines Logo
9:20 am - 12:06 pm
SYD
-
STL
41h 46m
1 stop
$1,201Asiana Airlines
Thu, Jun 11 - Tue, Jun 16
Air Canada Logo
5:10 am - 7:20 am
STL
-
SYD
35h 10m
2 stops
Air Canada Logo
9:20 am - 12:40 pm
SYD
-
STL
42h 20m
2 stops
$1,252Air Canada
Sun, Aug 23 - Tue, Sep 1
Air Canada Logo
1:05 pm - 7:20 am
STL
-
SYD
27h 15m
2 stops
Air Canada Logo
9:20 am - 8:25 pm
SYD
-
STL
26h 05m
2 stops
$1,263Air Canada
Sun, May 3 - Sun, May 10
Air Canada Logo
7:05 am - 7:20 am
STL
-
SYD
33h 15m
2 stops
Air Canada Logo
9:20 am - 8:25 pm
SYD
-
STL
26h 05m
2 stops
$1,268Air Canada
Wed, May 20 - Wed, May 27
Air Canada Logo
7:05 am - 7:20 am
STL
-
SYD
33h 15m
2 stops
Air Canada Logo
9:20 am - 8:25 pm
SYD
-
STL
26h 05m
2 stops
$1,270Air Canada
Thu, May 21 - Thu, May 28
Air Canada Logo
1:05 pm - 7:20 am
STL
-
SYD
51h 15m
3 stops
Air Canada Logo
9:20 am - 8:25 pm
SYD
-
STL
50h 05m
2 stops
$1,271Air Canada
Sun, May 3 - Sun, May 10

Air Canada flights from St. Louis to Sydney

Our best Air Canada deals on St. Louis to Sydney flight tickets
Air Canada
Jun 11
STL1:05 pmLambert-St Louis
27h 15m
2 stops
SYD7:20 amSydney Kingsford Smith
Jun 16
SYD9:20 amSydney Kingsford Smith
41h 46m
2 stops
STL12:06 pmLambert-St Louis
$1,156
Air Canada
Jun 11
STL1:05 pmLambert-St Louis
51h 15m
3 stops
SYD7:20 amSydney Kingsford Smith
Jun 16
SYD9:20 amSydney Kingsford Smith
41h 46m
2 stops
STL12:06 pmLambert-St Louis
$1,164
Air Canada
Jul 13
STL5:10 amLambert-St Louis
35h 10m
2 stops
SYD7:20 amSydney Kingsford Smith
Jul 19
SYD9:20 amSydney Kingsford Smith
43h 42m
2 stops
STL2:02 pmLambert-St Louis
$1,167

Qantas Airways flights from St. Louis to Sydney

Our best Qantas Airways deals on St. Louis to Sydney flight tickets
Qantas Airways
May 20
STL6:21 amLambert-St Louis
35h 59m
2 stops
SYD9:20 amSydney Kingsford Smith
May 27
SYD12:00 pmSydney Kingsford Smith
19h 33m
1 stop
STL4:33 pmLambert-St Louis
$1,403
Qantas Airways
May 5
STL6:21 amLambert-St Louis
45h 49m
2 stops
SYD7:10 pmSydney Kingsford Smith
May 12
SYD12:00 pmSydney Kingsford Smith
20h 21m
1 stop
STL5:21 pmLambert-St Louis
$1,443
Qantas Airways
May 5
STL3:38 pmLambert-St Louis
24h 17m
1 stop
SYD6:55 amSydney Kingsford Smith
May 12
SYD5:50 pmSydney Kingsford Smith
21h 09m
1 stop
STL11:59 pmLambert-St Louis
$1,449

momondo 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, momondo users made 832,500 searches. Data last updated April 10, 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 round-trip

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 6/11

1:05 pm-7:20 am

2 stops27h 15m

Sydney Kingsford Smith

Tue 6/16

9:20 am-12:06 pm

2 stops41h 46m

$1,156

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 6/11

1:05 pm-7:20 am

3 stops51h 15m

Sydney Kingsford Smith

Tue 6/16

9:20 am-12:06 pm

2 stops41h 46m

$1,164

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 7/13

5:10 am-7:20 am

2 stops35h 10m

Sydney Kingsford Smith

Sun 7/19

9:20 am-2:02 pm

2 stops43h 42m

$1,167

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 9/7

5:10 am-7:20 am

2 stops35h 10m

Sydney Kingsford Smith

Mon 9/14

9:20 am-2:00 pm

2 stops43h 40m

$1,180

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 6/11

8:40 am-7:20 am

1 stop31h 40m

Sydney Kingsford Smith

Tue 6/16

9:20 am-12:06 pm

1 stop41h 46m

$1,201

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 8/23

5:10 am-7:20 am

2 stops35h 10m

Sydney Kingsford Smith

Tue 9/1

9:20 am-12:40 pm

2 stops42h 20m

$1,252
Quickest round-trip

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 5/3

1:05 pm-7:20 am

2 stops27h 15m

Sydney Kingsford Smith

Sun 5/10

9:20 am-8:25 pm

2 stops26h 05m

$1,263

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 5/20

7:05 am-7:20 am

2 stops33h 15m

Sydney Kingsford Smith

Wed 5/27

9:20 am-8:25 pm

2 stops26h 05m

$1,268

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 5/21

7:05 am-7:20 am

2 stops33h 15m

Sydney Kingsford Smith

Thu 5/28

9:20 am-8:25 pm

2 stops26h 05m

$1,270

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 5/3

1:05 pm-7:20 am

3 stops51h 15m

Sydney Kingsford Smith

Sun 5/10

9:20 am-8:25 pm

2 stops50h 05m

$1,271

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

See travel insights to Sydney from

How to get the cheapest flight ticket from St. Louis to Sydney

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between St. Louis and Sydney?

What is the cheapest month to fly to Sydney?

In general, March is the cheapest month to fly from St. Louis to Sydney. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $1,233. If you are unable to visit Sydney during the month of March, then departing from St. Louis during the month October is also very affordable. Most momondo users find prices during this month for around $1,269.

Can stopping save me money on St. Louis to Sydney flights?

You could potentially save up to 3% on your flight if you consider stops on a St. Louis to Sydney flight.

How have St. Louis to Sydney flight prices changed over time?

When to book flights from St. Louis to Sydney

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Sydney according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to Sydney (STL to SYD) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Sydney

Fastest flight time

20h 04m

Direct flights

None
The fastest flight from St. Louis to Sydney takes 20h 04m
There are no direct flights from St. Louis to Sydney. There are no popular flight routes from St. Louis to Sydney.
Search flight deals

Frequently asked questions about flying from St. Louis to Sydney

  • How far is Lambert-St Louis to Sydney Kingsford Smith by plane?

    Lambert-St Louis and Sydney Kingsford Smith are 9057.2 mi apart from one another. A reasonable flight in good conditions will take 20h 04m.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Sydney Kingsford Smith Airport?

    Prices for flights from Lambert-St Louis Airport to Sydney Kingsford Smith Airport are updated daily.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Sydney Kingsford Smith Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to Sydney Kingsford Smith Airport?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Lambert-St Louis Airport to Sydney Kingsford Smith Airport.

  • What documentation or ID do you need to fly to Sydney Kingsford Smith Airport?

    The travel and health documents you'll need for your trip to Sydney Kingsford Smith Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Sydney Kingsford Smith Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from St. Louis to Sydney?

Best airlines flying from St. Louis to Sydney

Compare and see reviews for airlines that fly from St. Louis to Sydney with momondo
Airline
Rating
Free Cancellation
Price
Fiji AirwaysPriceFrom $887Free CancellationRating
8.1
239 reviews
Search Fiji Airways flights
Qantas AirwaysPriceFrom $1,094Free CancellationRating
7.5
1,018 reviews
Search Qantas Airways flights
United AirlinesPriceFrom $1,144Free CancellationRating
7.4
9,563 reviews
Search United Airlines flights
American AirlinesPriceFrom $1,233Free CancellationRating
7.1
11,567 reviews
Search American Airlines flights

Traveling to a place near Sydney?

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

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Sydney?

It is quick and easy to find St. Louis to Sydney flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Sydney that suits you.

Can I find flights from St. Louis to Sydney with flexible booking policies on momondo?

Yes. All flights to Sydney from St. Louis on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from St. Louis to Sydney?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Sydney from St. Louis.

I’m not ready to book a flight from St. Louis to Sydney right now. Can momondo alert me if prices change?

If you are not ready to book a flight from St. Louis to Sydney now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Sydney and let you know when they change.

An easier way to manage your Sydney trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Sun 5/10
Sun 5/17
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Australia