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Cheap flights from St. Louis to Sydney from $670

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 3/2. 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
0 bags

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Find the cheapest flights from St. Louis to Sydney

Cheap round-trip flights

Enter your travel dates to find the best prices.
Qantas Airways Logo
7:04 am - 9:00 am
STL
-
SYD
32h 56m1 stop
Qantas Airways Logo
7:05 am - 11:59 pm
SYD
-
STL
33h 54m2 stops
$918Qantas Airways
Tue, Feb 10 - Tue, Feb 17
Qantas Airways Logo
7:04 am - 9:00 am
STL
-
SYD
32h 56m1 stop
Qantas Airways Logo
7:05 am - 11:59 pm
SYD
-
STL
33h 54m2 stops
$939Qantas Airways
Thu, Jan 22 - Thu, Jan 29
Qantas Airways Logo
7:04 am - 7:35 am
STL
-
SYD
55h 31m2 stops
Qantas Airways Logo
11:20 am - 11:59 pm
SYD
-
STL
29h 39m1 stop
$940Qantas Airways
Thu, Jan 29 - Thu, Feb 5
Qantas Airways Logo
6:38 am - 8:50 pm
STL
-
SYD
45h 12m2 stops
Qantas Airways Logo
11:20 am - 11:59 pm
SYD
-
STL
28h 39m1 stop
$962Qantas Airways
Wed, Feb 25 - Mon, Mar 16
Qantas Airways Logo
4:13 pm - 7:35 am
STL
-
SYD
46h 22m2 stops
Qantas Airways Logo
11:20 am - 11:59 pm
SYD
-
STL
28h 39m1 stop
$1,006Qantas Airways
Sat, Mar 7 - Sat, Mar 14
Qantas Airways Logo
6:18 pm - 9:10 am
STL
-
SYD
45h 52m2 stops
Qantas Airways Logo
11:20 am - 11:59 pm
SYD
-
STL
28h 39m1 stop
$1,008Qantas Airways
Sat, Mar 7 - Sat, Mar 14
Qantas Airways Logo
5:12 pm - 5:40 pm
STL
-
SYD
31h 28m2 stops
Qantas Airways Logo
11:20 am - 11:59 pm
SYD
-
STL
29h 39m1 stop
$1,086Qantas Airways
Wed, Jan 21 - Sat, Jan 31
Qantas Airways Logo
6:50 pm - 2:50 pm
STL
-
SYD
27h 00m2 stops
Qantas Airways Logo
5:45 pm - 11:59 pm
SYD
-
STL
23h 14m1 stop
$1,096Qantas Airways
Sun, Feb 15 - Sun, Feb 22
Qantas Airways Logo
6:38 am - 9:00 am
STL
-
SYD
33h 22m1 stop
Qantas Airways Logo
7:15 pm - 11:59 pm
SYD
-
STL
45h 44m2 stops
$1,115Qantas Airways
Fri, Feb 13 - Tue, Feb 17
Qantas Airways Logo
6:38 am - 9:00 am
STL
-
SYD
33h 22m1 stop
Qantas Airways Logo
7:15 pm - 11:59 pm
SYD
-
STL
45h 44m2 stops
$1,116Qantas Airways
Fri, Feb 13 - Tue, Feb 17

Air Canada flights from St. Louis to Sydney

Our best Air Canada deals on St. Louis to Sydney flight tickets
Air Canada
Feb 10
STL4:05 pmLambert-St Louis
48h 30m
2 stops
SYD9:35 amSydney Kingsford Smith
Feb 17
SYD11:20 amSydney Kingsford Smith
45h 09m
2 stops
STL3:29 pmLambert-St Louis
$1,147
Find similar
Air Canada
Apr 4
STL4:05 pmLambert-St Louis
48h 15m
2 stops
SYD7:20 amSydney Kingsford Smith
Apr 11
SYD9:20 amSydney Kingsford Smith
45h 04m
2 stops
STL3:24 pmLambert-St Louis
$1,189
Find similar
Air Canada
Feb 25
STL4:05 pmLambert-St Louis
48h 30m
2 stops
SYD9:35 amSydney Kingsford Smith
Mar 16
SYD10:25 amSydney Kingsford Smith
45h 04m
2 stops
STL3:29 pmLambert-St Louis
$1,193
Find similar

Qantas Airways flights from St. Louis to Sydney

Our best Qantas Airways deals on St. Louis to Sydney flight tickets
Qantas Airways
Feb 10
STL7:04 amLambert-St Louis
32h 56m
1 stop
SYD9:00 amSydney Kingsford Smith
Feb 17
SYD7:05 amSydney Kingsford Smith
33h 54m
2 stops
STL11:59 pmLambert-St Louis
$918
Find similar
Qantas Airways
Jan 22
STL7:04 amLambert-St Louis
32h 56m
1 stop
SYD9:00 amSydney Kingsford Smith
Jan 29
SYD7:05 amSydney Kingsford Smith
33h 54m
2 stops
STL11:59 pmLambert-St Louis
$939
Find similar
Qantas Airways
Jan 29
STL7:04 amLambert-St Louis
55h 31m
2 stops
SYD7:35 amSydney Kingsford Smith
Feb 5
SYD11:20 amSydney Kingsford Smith
29h 39m
1 stop
STL11:59 pmLambert-St Louis
$940
Find similar

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 January 2, 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

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 2/10

7:04 am-9:00 am

1 stop32h 56m

Sydney Kingsford Smith

Tue 2/17

7:05 am-11:59 pm

2 stops33h 54m

$918

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 1/22

7:04 am-9:00 am

1 stop32h 56m

Sydney Kingsford Smith

Thu 1/29

7:05 am-11:59 pm

2 stops33h 54m

$939

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Thu 1/29

7:04 am-7:35 am

2 stops55h 31m

Sydney Kingsford Smith

Thu 2/5

11:20 am-11:59 pm

1 stop29h 39m

$940

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 2/25

6:38 am-8:50 pm

2 stops45h 12m

Sydney Kingsford Smith

Mon 3/16

11:20 am-11:59 pm

1 stop28h 39m

$962

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 3/7

4:13 pm-7:35 am

2 stops46h 22m

Sydney Kingsford Smith

Sat 3/14

11:20 am-11:59 pm

1 stop28h 39m

$1,006

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 3/7

6:18 pm-9:10 am

2 stops45h 52m

Sydney Kingsford Smith

Sat 3/14

11:20 am-11:59 pm

1 stop28h 39m

$1,008

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 1/21

5:12 pm-5:40 pm

2 stops31h 28m

Sydney Kingsford Smith

Sat 1/31

11:20 am-11:59 pm

1 stop29h 39m

$1,086

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 2/15

6:50 pm-2:50 pm

2 stops27h 00m

Sydney Kingsford Smith

Sun 2/22

5:45 pm-11:59 pm

1 stop23h 14m

$1,096

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 2/13

6:38 am-9:00 am

1 stop33h 22m

Sydney Kingsford Smith

Tue 2/17

7:15 pm-11:59 pm

2 stops45h 44m

$1,115

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Fri 2/13

6:38 am-9:00 am

1 stop33h 22m

Sydney Kingsford Smith

Tue 2/17

7:15 pm-11:59 pm

2 stops45h 44m

$1,116

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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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, August 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 $1,275. If you are unable to visit Sydney during the month of August, then departing from St. Louis during the month October is also very affordable. Most momondo users find prices during this month for around $1,331.

How far in advance should I book a flight to Sydney?

You are more likely to see cheaper flights to Sydney from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Sydney for around $1,453 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Sydney from St. Louis for as low as $948 on momondo.

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

You could potentially save up to 9% on your flight if you consider stops on a St. Louis to Sydney flight.

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

28h 20m

Direct flights

None
The fastest flight from St. Louis to Sydney takes 28h 20m
There are no direct flights from St. Louis to Sydney. There are no popular flight routes from St. Louis to Sydney.
Search flight deals

  • 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 28h 20m.

  • 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
Air CanadaPriceFrom $897Free CancellationRating
7.1
10,574 reviews
Search Air Canada flights
Fiji AirwaysPriceFrom $1,132Free CancellationRating
8.0
212 reviews
Search Fiji Airways flights
Qantas AirwaysPriceFrom $1,207Free CancellationRating
7.5
961 reviews
Search Qantas Airways flights
United AirlinesPriceFrom $1,314Free CancellationRating
7.4
9,128 reviews
Search United Airlines flights
American AirlinesPriceFrom $1,340Free CancellationRating
7.2
11,075 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
Randwick
Coogee
Manly
Penrith
Cronulla
Lithgow
Leura
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.

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