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Cheap flights from Seattle to Sydney from $586

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Sydney departing on 18/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Seattle to Sydney

Cheap return flights

Enter your travel dates to find the best prices.
Air Canada Logo
20:00 - 16:40
SEA
-
SYD
25h 40m2 stops
Air Canada Logo
19:15 - 09:31
SYD
-
SEA
32h 16m2 stops
$1,484Air Canada
Sun, 1 Mar - Sat, 14 Mar
Air Canada Logo
15:40 - 14:40
SEA
-
SYD
28h 00m2 stops
Air Canada Logo
09:00 - 09:31
SYD
-
SEA
19h 31m2 stops
$1,485Air Canada
Sat, 7 Feb - Tue, 24 Feb
ANA Logo
08:42 - 19:15
SEA
-
SYD
41h 33m2 stops
ANA Logo
20:55 - 14:25
SYD
-
SEA
34h 30m1 stop
$1,491ANA
Sun, 3 May - Wed, 27 May
Multiple Airlines Logo
10:05 - 09:35
SEA
-
SYD
28h 30m1 stop
Multiple Airlines Logo
21:20 - 09:31
SYD
-
SEA
30h 11m2 stops
$1,494Multiple Airlines
Tue, 10 Feb - Tue, 10 Mar
Air Canada Logo
20:00 - 09:35
SEA
-
SYD
18h 35m1 stop
Air Canada Logo
11:20 - 14:31
SYD
-
SEA
22h 11m1 stop
$1,496Air Canada
Sun, 1 Feb - Tue, 17 Feb
Air Canada Logo
20:00 - 09:35
SEA
-
SYD
18h 35m1 stop
Air Canada Logo
11:20 - 22:06
SYD
-
SEA
29h 46m1 stop
$1,497Air Canada
Sun, 1 Feb - Wed, 18 Feb
Air Canada Logo
05:50 - 09:35
SEA
-
SYD
32h 45m1 stop
Air Canada Logo
11:20 - 09:31
SYD
-
SEA
17h 11m1 stop
$1,499Air Canada
Sun, 1 Feb - Tue, 17 Feb
Air Canada Logo
20:00 - 09:35
SEA
-
SYD
18h 35m1 stop
Air Canada Logo
11:20 - 14:31
SYD
-
SEA
22h 11m1 stop
$1,500Air Canada
Tue, 3 Feb - Sun, 15 Feb
Air Canada Logo
15:40 - 09:35
SEA
-
SYD
22h 55m1 stop
Air Canada Logo
11:20 - 22:06
SYD
-
SEA
29h 46m1 stop
$1,502Air Canada
Tue, 3 Feb - Mon, 16 Feb
Air Canada Logo
19:20 - 07:20
SEA
-
SYD
19h 00m1 stop
Air Canada Logo
09:20 - 09:15
SYD
-
SEA
16h 55m1 stop
$1,503Air Canada
Sat, 2 May - Fri, 22 May

Air Canada flights from Seattle to Sydney

Our best Air Canada deals on Seattle to Sydney flight tickets
Air Canada
1 Mar
SEA20:00Seattle/Tacoma Intl
25h 40m
2 stops
SYD16:40Sydney Kingsford Smith
14 Mar
SYD19:15Sydney Kingsford Smith
32h 16m
2 stops
SEA09:31Seattle/Tacoma Intl
$1,484
Find similar
Air Canada
7 Feb
SEA15:40Seattle/Tacoma Intl
28h 00m
2 stops
SYD14:40Sydney Kingsford Smith
24 Feb
SYD09:00Sydney Kingsford Smith
19h 31m
2 stops
SEA09:31Seattle/Tacoma Intl
$1,485
Find similar
Air Canada
1 Feb
SEA10:05Seattle/Tacoma Intl
28h 30m
1 stop
SYD09:35Sydney Kingsford Smith
16 Feb
SYD11:20Sydney Kingsford Smith
22h 11m
1 stop
SEA14:31Seattle/Tacoma Intl
$1,496
Find similar

United Airlines flights from Seattle to Sydney

Our best United Airlines deals on Seattle to Sydney flight tickets
United Airlines
14 Dec
SEA07:00Seattle/Tacoma Intl
28h 20m
1 stop
SYD06:20Sydney Kingsford Smith
16 Dec
SYD08:30Sydney Kingsford Smith
35h 20m
2 stops
SEA00:50Seattle/Tacoma Intl
$1,939
Find similar
United Airlines
24 Dec
SEA09:06Seattle/Tacoma Intl
28h 59m
1 stop
SYD09:05Sydney Kingsford Smith
12 Jan
SYD11:20Sydney Kingsford Smith
28h 52m
2 stops
SEA21:12Seattle/Tacoma Intl
$2,212
Find similar
United Airlines
24 Dec
SEA09:06Seattle/Tacoma Intl
28h 59m
1 stop
SYD09:05Sydney Kingsford Smith
8 Jan
SYD11:50Sydney Kingsford Smith
30h 09m
1 stop
SEA22:59Seattle/Tacoma Intl
$2,280
Find similar

momondo Fare Finder

 
Customise your flight search to find flights from Seattle 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 78,305 searches. Data last updated 11 December 2025.
Use the filters below to find and compare flights from Seattle to Sydney that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 1/3

20:00-16:40

2 stops25h 40m

Sydney Kingsford Smith

Sat 14/3

19:15-09:31

2 stops32h 16m

$1,484

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 7/2

15:40-14:40

2 stops28h 00m

Sydney Kingsford Smith

Tue 24/2

09:00-09:31

2 stops19h 31m

$1,485

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 3/5

08:42-19:15

2 stops41h 33m

Sydney Kingsford Smith

Wed 27/5

20:55-14:25

1 stop34h 30m

$1,491

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 10/2

10:05-09:35

1 stop28h 30m

Sydney Kingsford Smith

Tue 10/3

21:20-09:31

2 stops30h 11m

$1,494

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 1/2

20:00-09:35

1 stop18h 35m

Sydney Kingsford Smith

Tue 17/2

11:20-14:31

1 stop22h 11m

$1,496

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 1/2

20:00-09:35

1 stop18h 35m

Sydney Kingsford Smith

Wed 18/2

11:20-22:06

1 stop29h 46m

$1,497

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 1/2

05:50-09:35

1 stop32h 45m

Sydney Kingsford Smith

Tue 17/2

11:20-09:31

1 stop17h 11m

$1,499

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 3/2

20:00-09:35

1 stop18h 35m

Sydney Kingsford Smith

Sun 15/2

11:20-14:31

1 stop22h 11m

$1,500

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 3/2

15:40-09:35

1 stop22h 55m

Sydney Kingsford Smith

Mon 16/2

11:20-22:06

1 stop29h 46m

$1,502

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 2/5

19:20-07:20

1 stop19h 00m

Sydney Kingsford Smith

Fri 22/5

09:20-09:15

1 stop16h 55m

$1,503

Flights are sorted by cheapest return 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 Seattle 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?

The month of August is, on average, the cheapest month to fly to Sydney from Seattle, with most prices found around $1,271. If you aren’t able to travel to Sydney during the month of August, then flying in September is also cheap. Prices for this month can be found on momondo for an average of $1,319.

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

Our data shows that Monday is the least expensive day to fly to Sydney. Tickets to fly out on this day can be as low as $1,452. The most expensive day to fly to Sydney is Saturday, with ticket prices averaging around $1,754.

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 afternoon. momondo users have found flights departing from Seattle to Sydney in the afternoon for as low as $1,387. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $1,702 on average. Flights to Sydney from Seattle in the morning are generally more expensive because this time of day is more convenient for travellers’ schedules.

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

You are more likely to see cheaper flights to Sydney from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Sydney for around $1,595 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Sydney from Seattle for as low as $1,317 on momondo.

Can stopping save me money on Seattle to Sydney flights?

You could potentially save up to 1% on your flight if you consider stops on a Seattle to Sydney flight.

How have Seattle to Sydney flight prices changed over time?

As of December 2025, prices for Seattle to Sydney flights are approximately 48% cheaper when compared to flights at the same time last year.

When to book flights from Seattle to Sydney

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

Cheap Seattle to Sydney (SEA to SYD) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to Sydney

Fastest flight time

18h 35m

Direct flights

None
The fastest flight from Seattle to Sydney takes 18h 35m
There are no direct flights from Seattle to Sydney. There are no popular flight routes from Seattle to Sydney.
Search flight deals

  • How far is Seattle/Tacoma Intl to Sydney Kingsford Smith by plane?

    Seattle/Tacoma Intl and Sydney Kingsford Smith are 12462.2 km apart from one another. In terms of flight time, this usually takes a little over 18h 35m.

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Sydney Kingsford Smith Airport?

    Prices for flights from Seattle/Tacoma Intl Airport to Sydney Kingsford Smith Airport refresh daily.

  • How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Sydney Kingsford Smith Airport?

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to Sydney Kingsford Smith Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and stopovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to Sydney Kingsford Smith Airport.

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

    The required travel and health documents for your Sydney Kingsford Smith Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's licence and a passport valid for six months after your intended arrival at Sydney Kingsford Smith Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

  • What is the most popular airline from Seattle to Sydney?

Best airlines flying from Seattle to Sydney

Compare and see reviews for airlines that fly from Seattle to Sydney with momondo
Airline
Rating
Free cancellation
Price
United AirlinesPriceFrom $1,200Free cancellationRating
7.4
9,095 reviews
Search United Airlines flights
Air CanadaPriceFrom $1,262Free cancellationRating
7.1
10,514 reviews
Search Air Canada flights
Alaska AirlinesPriceFrom $1,280Free cancellationRating
8.0
11,429 reviews
Search Alaska Airlines flights

Travelling to a place near Sydney?

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

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to Sydney?

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Seattle to Sydney for you.

Can I find flights from Seattle to Sydney with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Seattle to Sydney flights to just show those with flexible booking policies.

How can momondo help me find flights from Seattle to Sydney?

Once you have performed a search for Seattle to Sydney flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

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

Of course. momondo tracks the price of Seattle to Sydney flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

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