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Cheap flights from St. Louis to Sydney from $578

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 11/6. 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 (STL-SYD)

Cheap round-trip flights

Qantas Airways Logo
1:55 pm - 6:55 amSTL-SYD
24h 00m1 stop
Qantas Airways Logo
6:05 am - 4:07 pmSYD-STL
27h 02m2 stops
$1,092Qantas Airways
Find Deal
Fri, Nov 28 - Sun, Dec 14
Qantas Airways Logo
3:59 pm - 6:55 amSTL-SYD
21h 56m1 stop
Qantas Airways Logo
5:30 pm - 11:42 pmSYD-STL
23h 12m2 stops
$1,104Qantas Airways
Find Deal
Tue, Nov 4 - Tue, Nov 11
Qantas Airways Logo
7:00 am - 9:20 amSTL-SYD
33h 20m2 stops
Qantas Airways Logo
2:20 pm - 7:30 pmSYD-STL
22h 10m1 stop
$1,106Qantas Airways
Find Deal
Wed, Nov 5 - Sun, Nov 23
Fiji Airways Logo
5:58 pm - 12:30 pmSTL-SYD
25h 32m2 stops
Fiji Airways Logo
2:10 pm - 7:30 pmSYD-STL
22h 20m2 stops
$1,142Fiji Airways
Find Deal
Tue, Nov 4 - Tue, Nov 11
Air Canada Logo
4:05 pm - 8:35 amSTL-SYD
48h 30m2 stops
Air Canada Logo
11:20 am - 3:29 pmSYD-STL
45h 09m2 stops
$1,184Air Canada
Find Deal
Mon, Oct 27 - Mon, Nov 10
Air Canada Logo
4:05 pm - 9:35 amSTL-SYD
48h 30m2 stops
Air Canada Logo
11:20 am - 3:29 pmSYD-STL
45h 09m2 stops
$1,194Air Canada
Find Deal
Sat, Nov 8 - Fri, Nov 21
United Airlines Logo
4:50 pm - 7:00 amSTL-SYD
23h 10m2 stops
United Airlines Logo
10:30 am - 6:57 pmSYD-STL
24h 27m2 stops
$1,263United Airlines
Find Deal
Sun, Sep 28 - Sun, Oct 5
United Airlines Logo
1:40 pm - 7:00 amSTL-SYD
26h 20m2 stops
United Airlines Logo
11:20 am - 5:09 pmSYD-STL
21h 49m1 stop
$1,267United Airlines
Find Deal
Sun, Sep 28 - Sun, Oct 5
American Airlines Logo
7:00 am - 7:05 amSTL-SYD
33h 05m1 stop
American Airlines Logo
1:10 pm - 7:33 pmSYD-STL
22h 23m1 stop
$1,344American Airlines
Find Deal
Sun, Sep 28 - Sun, Oct 5
American Airlines Logo
3:59 pm - 6:55 amSTL-SYD
23h 56m1 stop
American Airlines Logo
1:10 pm - 8:51 pmSYD-STL
23h 41m1 stop
$1,345American Airlines
Find Deal
Mon, Sep 29 - Mon, Oct 6

United Airlines flights from St. Louis to Sydney

Our best United Airlines deals on St. Louis to Sydney flight tickets
United Airlines
Sep 28
STL4:50 pmLambert-St Louis
23h 10m
2 stops
SYD7:00 amSydney Kingsford Smith
Oct 5
SYD10:30 amSydney Kingsford Smith
24h 27m
2 stops
STL6:57 pmLambert-St Louis
$1,263
Find similar
United Airlines
Sep 28
STL1:40 pmLambert-St Louis
26h 20m
2 stops
SYD7:00 amSydney Kingsford Smith
Oct 5
SYD11:20 amSydney Kingsford Smith
21h 49m
1 stop
STL5:09 pmLambert-St Louis
$1,267
Find similar
United Airlines
Nov 25
STL4:35 pmLambert-St Louis
21h 25m
1 stop
SYD7:00 amSydney Kingsford Smith
Dec 17
SYD11:50 amSydney Kingsford Smith
27h 08m
1 stop
STL9:58 pmLambert-St Louis
$1,278
Find similar

American Airlines flights from St. Louis to Sydney

Our best American Airlines deals on St. Louis to Sydney flight tickets
American Airlines
Sep 28
STL7:00 amLambert-St Louis
33h 05m
1 stop
SYD7:05 amSydney Kingsford Smith
Oct 5
SYD1:10 pmSydney Kingsford Smith
22h 23m
1 stop
STL7:33 pmLambert-St Louis
$1,344
Find similar
American Airlines
Sep 29
STL3:59 pmLambert-St Louis
23h 56m
1 stop
SYD6:55 amSydney Kingsford Smith
Oct 6
SYD1:10 pmSydney Kingsford Smith
23h 41m
1 stop
STL8:51 pmLambert-St Louis
$1,345
Find similar
American Airlines
Oct 29
STL8:49 amLambert-St Louis
30h 06m
1 stop
SYD6:55 amSydney Kingsford Smith
Nov 15
SYD2:20 pmSydney Kingsford Smith
22h 10m
1 stop
STL7:30 pmLambert-St Louis
$1,346
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 August 16, 2025.
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

Fri 11/28

1:55 pm-6:55 am

1 stop24h 00m

Sydney Kingsford Smith

Sun 12/14

6:05 am-4:07 pm

2 stops27h 02m

$1,092

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 11/4

3:59 pm-6:55 am

1 stop21h 56m

Sydney Kingsford Smith

Tue 11/11

5:30 pm-11:42 pm

2 stops23h 12m

$1,104

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Wed 11/5

7:00 am-9:20 am

2 stops33h 20m

Sydney Kingsford Smith

Sun 11/23

2:20 pm-7:30 pm

1 stop22h 10m

$1,106

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Tue 11/4

5:58 pm-12:30 pm

2 stops25h 32m

Sydney Kingsford Smith

Tue 11/11

2:10 pm-7:30 pm

2 stops22h 20m

$1,142

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 10/27

4:05 pm-8:35 am

2 stops48h 30m

Sydney Kingsford Smith

Mon 11/10

11:20 am-3:29 pm

2 stops45h 09m

$1,184

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sat 11/8

4:05 pm-9:35 am

2 stops48h 30m

Sydney Kingsford Smith

Fri 11/21

11:20 am-3:29 pm

2 stops45h 09m

$1,194

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 9/28

4:50 pm-7:00 am

2 stops23h 10m

Sydney Kingsford Smith

Sun 10/5

10:30 am-6:57 pm

2 stops24h 27m

$1,263

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 9/28

1:40 pm-7:00 am

2 stops26h 20m

Sydney Kingsford Smith

Sun 10/5

11:20 am-5:09 pm

1 stop21h 49m

$1,267

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Sun 9/28

7:00 am-7:05 am

1 stop33h 05m

Sydney Kingsford Smith

Sun 10/5

1:10 pm-7:33 pm

1 stop22h 23m

$1,344

St. LouisSydney

STL - SYD

STLSYD

Lambert-St Louis

Mon 9/29

3:59 pm-6:55 am

1 stop23h 56m

Sydney Kingsford Smith

Mon 10/6

1:10 pm-8:51 pm

1 stop23h 41m

$1,345

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 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 $1,257. If you are unable to visit Sydney during the month of August, then departing from St. Louis during the month November is also very affordable. Most momondo users find prices during this month for around $1,370.

What is the cheapest day to depart on your flight to Sydney?

The cheapest day to depart from St. Louis to Sydney is on a Wednesday when prices can be found for as low as $1,392. The most expensive day to fly to Sydney is Saturday, with ticket prices averaging around $1,518.

What is the cheapest time of day to depart on your flight to Sydney?

According to our data, the cheapest time of day to fly to Sydney is in the evening. momondo users have found flights departing from St. Louis to Sydney in the evening for as low as $1,440. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights to Sydney are more costly at noon, with an average ticket price of $1,882. Departure times at noon fall within the peak daily travel times, which is why tickets can be more expensive.

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 $1,465 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 $1,272 on momondo.

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

You could potentially save up to 64% 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

Best Price Found

$578

Fastest flight time

20h 13m

Direct flights

None

Airports in Sydney

1 airport
The best one-way flight to Sydney from St. Louis in the past 72 hours is $578. The best round-trip flight deal from St. Louis to Sydney found on momondo in the last 72 hours is $1,092.
The fastest flight from St. Louis to Sydney takes 20h 13m
There are no direct flights from St. Louis to Sydney. Popular non-direct route for this connection is Lambert-St Louis Airport - Sydney Kingsford Smith Airport.
There is 1 airport near Sydney: Sydney Kingsford Smith (SYD)
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 20h 13m.

  • 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
8.0
204 reviews
Search Fiji Airways flights
Air CanadaPriceFrom $1,078Free CancellationRating
7.1
9,966 reviews
Search Air Canada flights
Air New ZealandPriceFrom $1,173Free CancellationRating
8.0
504 reviews
Search Air New Zealand flights
United AirlinesPriceFrom $1,209Free CancellationRating
7.4
8,916 reviews
Search United Airlines flights
American AirlinesPriceFrom $1,240Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
Qantas AirwaysPriceFrom $1,260Free CancellationRating
7.5
895 reviews
Search Qantas Airways 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
Cronulla
Coogee
Lithgow
Penrith
Manly
Charlestown
Swansea
Leura
Terrigal

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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