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Cheap flights from Seattle to Sydney from $438

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 1/12. 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

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Cheap return flights

Enter your travel dates to find the best prices.
Qantas Airways Logo
15:35 - 09:00SEA-SYD
22h 25m1 stop
Qantas Airways Logo
11:20 - 14:16SYD-SEA
20h 56m1 stop
$1,270Qantas Airways
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Tue, 17 Feb - Tue, 10 Mar
Multiple Airlines Logo
17:40 - 07:30SEA-SYD
20h 50m1 stop
Multiple Airlines Logo
17:45 - 21:36SYD-SEA
20h 51m1 stop
$1,271Multiple Airlines
Find Deal
Sun, 19 Apr - Thu, 14 May
Multiple Airlines Logo
15:40 - 20:15SEA-SYD
33h 35m1 stop
Multiple Airlines Logo
21:40 - 13:30SYD-SEA
34h 50m2 stops
$1,298Multiple Airlines
Find Deal
Sat, 29 Nov - Fri, 12 Dec
Alaska Airlines Logo
07:00 - 19:45SEA-SYD
17h 45m1 stop
Alaska Airlines Logo
21:40 - 05:18SYD-SEA
26h 38m1 stop
$1,367Alaska Airlines
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Tue, 13 Jan - Mon, 19 Jan
Hawaiian Airlines Logo
11:35 - 19:45SEA-SYD
37h 10m1 stop
Hawaiian Airlines Logo
21:40 - 21:02SYD-SEA
18h 22m1 stop
$1,370Hawaiian Airlines
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Tue, 2 Dec - Fri, 9 Jan
Hawaiian Airlines Logo
07:00 - 19:45SEA-SYD
17h 45m1 stop
Hawaiian Airlines Logo
21:40 - 23:21SYD-SEA
20h 41m1 stop
$1,373Hawaiian Airlines
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Wed, 12 Nov - Tue, 18 Nov
Alaska Airlines Logo
07:00 - 19:45SEA-SYD
17h 45m1 stop
Alaska Airlines Logo
21:40 - 06:46SYD-SEA
28h 06m2 stops
$1,381Alaska Airlines
Find Deal
Thu, 29 Jan - Tue, 10 Feb
ANA Logo
16:30 - 19:15SEA-SYD
33h 45m1 stop
ANA Logo
20:55 - 14:25SYD-SEA
34h 30m1 stop
$1,397ANA
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Mon, 20 Apr - Sun, 26 Apr
ANA Logo
16:30 - 19:15SEA-SYD
33h 45m1 stop
ANA Logo
20:55 - 21:29SYD-SEA
41h 34m2 stops
$1,451ANA
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Tue, 21 Apr - Thu, 30 Apr
Air Canada Logo
20:00 - 09:35SEA-SYD
18h 35m1 stop
Air Canada Logo
16:00 - 19:16SYD-SEA
22h 16m1 stop
$1,570Air Canada
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Sat, 22 Nov - Mon, 22 Dec

Hawaiian Airlines flights from Seattle to Sydney

Our best Hawaiian Airlines deals on Seattle to Sydney flight tickets
Hawaiian Airlines
27 Oct
SEA07:00Seattle/Tacoma Intl
18h 45m
1 stop
SYD19:45Sydney Kingsford Smith
11 Nov
SYD21:40Sydney Kingsford Smith
19h 17m
1 stop
SEA21:57Seattle/Tacoma Intl
$1,350
Find similar
Hawaiian Airlines
2 Dec
SEA11:35Seattle/Tacoma Intl
37h 10m
1 stop
SYD19:45Sydney Kingsford Smith
9 Jan
SYD21:40Sydney Kingsford Smith
18h 22m
1 stop
SEA21:02Seattle/Tacoma Intl
$1,370
Find similar
Hawaiian Airlines
12 Nov
SEA07:00Seattle/Tacoma Intl
17h 45m
1 stop
SYD19:45Sydney Kingsford Smith
18 Nov
SYD21:40Sydney Kingsford Smith
20h 41m
1 stop
SEA23:21Seattle/Tacoma Intl
$1,373
Find similar

Qantas Airways flights from Seattle to Sydney

Our best Qantas Airways deals on Seattle to Sydney flight tickets
Qantas Airways
17 Feb
SEA15:35Seattle/Tacoma Intl
22h 25m
1 stop
SYD09:00Sydney Kingsford Smith
10 Mar
SYD11:20Sydney Kingsford Smith
20h 56m
1 stop
SEA14:16Seattle/Tacoma Intl
$1,270
Find similar
Qantas Airways
27 Dec
SEA06:00Seattle/Tacoma Intl
32h 00m
1 stop
SYD09:00Sydney Kingsford Smith
17 Jan
SYD17:45Sydney Kingsford Smith
24h 01m
1 stop
SEA22:46Seattle/Tacoma Intl
$1,334
Find similar
Qantas Airways
19 Apr
SEA06:05Seattle/Tacoma Intl
32h 00m
1 stop
SYD07:05Sydney Kingsford Smith
14 May
SYD17:45Sydney Kingsford Smith
22h 04m
1 stop
SEA22:49Seattle/Tacoma Intl
$1,337
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 24 October 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

Tue 17/2

15:35-09:00

1 stop22h 25m

Sydney Kingsford Smith

Tue 10/3

11:20-14:16

1 stop20h 56m

$1,270

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 19/4

17:40-07:30

1 stop20h 50m

Sydney Kingsford Smith

Thu 14/5

17:45-21:36

1 stop20h 51m

$1,271

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 29/11

15:40-20:15

1 stop33h 35m

Sydney Kingsford Smith

Fri 12/12

21:40-13:30

2 stops34h 50m

$1,298

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 13/1

07:00-19:45

1 stop17h 45m

Sydney Kingsford Smith

Mon 19/1

21:40-05:18

1 stop26h 38m

$1,367

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 2/12

11:35-19:45

1 stop37h 10m

Sydney Kingsford Smith

Fri 9/1

21:40-21:02

1 stop18h 22m

$1,370

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Wed 12/11

07:00-19:45

1 stop17h 45m

Sydney Kingsford Smith

Tue 18/11

21:40-23:21

1 stop20h 41m

$1,373

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Thu 29/1

07:00-19:45

1 stop17h 45m

Sydney Kingsford Smith

Tue 10/2

21:40-06:46

2 stops28h 06m

$1,381

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Mon 20/4

16:30-19:15

1 stop33h 45m

Sydney Kingsford Smith

Sun 26/4

20:55-14:25

1 stop34h 30m

$1,397

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 21/4

16:30-19:15

1 stop33h 45m

Sydney Kingsford Smith

Thu 30/4

20:55-21:29

2 stops41h 34m

$1,451

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 22/11

20:00-09:35

1 stop18h 35m

Sydney Kingsford Smith

Mon 22/12

16:00-19:16

1 stop22h 16m

$1,570

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 September is, on average, the cheapest month to fly to Sydney from Seattle, with most prices found around $1,379. If you aren’t able to travel to Sydney during the month of September, then flying in August is also cheap. Prices for this month can be found on momondo for an average of $1,391.

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 $1,486. The most expensive day to fly to Sydney is Saturday, with ticket prices averaging around $1,796.

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 $1,419. 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 $1,742 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 $1,637 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 $1,357 on momondo.

Can stopping save me money on Seattle to Sydney flights?

You could potentially save up to 2% 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 October 2025, prices for Seattle to Sydney flights are approximately 44% 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

Direct flights

None
There are no direct flights from Seattle to Sydney. There are no popular flight routes from Seattle to Sydney.
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  • 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 17h 25m.

  • 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 $1,228Free cancellationRating
7.4
8,996 reviews
Search United Airlines flights
Air CanadaPriceFrom $1,292Free cancellationRating
7.1
10,357 reviews
Search Air Canada 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
Randwick
Cronulla
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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