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Cheap flights from Seattle to Sydney from $379

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 3/18. 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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0 bags

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Find the cheapest flights from Seattle to Sydney

Cheap round-trip flights

Enter your travel dates to find the best prices.
Qantas Airways Logo
3:57 pm - 2:25 pm
SEA
-
SYD
27h 28m2 stops
Qantas Airways Logo
9:25 pm - 9:58 pm
SYD
-
SEA
19h 33m1 stop
$903Qantas Airways
Wed, Jan 28 - Sun, Feb 8
Air Canada Logo
8:00 pm - 9:35 am
SEA
-
SYD
18h 35m1 stop
Air Canada Logo
11:20 am - 2:31 pm
SYD
-
SEA
22h 11m1 stop
$911Air Canada
Tue, Feb 3 - Sun, Feb 22
Air Canada Logo
8:00 pm - 9:35 am
SEA
-
SYD
18h 35m1 stop
Air Canada Logo
11:20 am - 9:31 am
SYD
-
SEA
17h 11m1 stop
$912Air Canada
Sun, Feb 15 - Sun, Feb 22
ANA Logo
4:30 pm - 9:25 am
SEA
-
SYD
23h 55m1 stop
ANA Logo
11:50 am - 8:48 pm
SYD
-
SEA
25h 58m2 stops
$921ANA
Tue, May 12 - Tue, May 26
ANA Logo
5:45 pm - 7:15 pm
SEA
-
SYD
32h 30m2 stops
ANA Logo
11:50 am - 8:48 pm
SYD
-
SEA
25h 58m2 stops
$925ANA
Tue, May 12 - Tue, May 26
Air Canada Logo
3:40 pm - 7:20 am
SEA
-
SYD
22h 40m1 stop
Air Canada Logo
6:30 am - 3:03 pm
SYD
-
SEA
25h 33m2 stops
$926Air Canada
Wed, Apr 8 - Tue, Apr 21
Air Canada Logo
8:00 pm - 9:35 am
SEA
-
SYD
18h 35m1 stop
Air Canada Logo
10:20 am - 9:31 am
SYD
-
SEA
17h 11m1 stop
$927Air Canada
Tue, Feb 10 - Tue, Mar 10
Air Canada Logo
10:05 am - 9:35 am
SEA
-
SYD
28h 30m1 stop
Air Canada Logo
10:20 am - 7:16 pm
SYD
-
SEA
26h 56m1 stop
$929Air Canada
Tue, Feb 17 - Tue, Mar 10
Air Canada Logo
8:00 pm - 2:40 pm
SEA
-
SYD
23h 40m2 stops
Air Canada Logo
11:20 am - 2:31 pm
SYD
-
SEA
22h 11m1 stop
$931Air Canada
Tue, Jan 20 - Tue, Feb 3
Air Canada Logo
8:00 pm - 4:40 pm
SEA
-
SYD
25h 40m2 stops
Air Canada Logo
11:20 am - 7:16 pm
SYD
-
SEA
26h 56m1 stop
$932Air Canada
Tue, Jan 20 - Tue, Feb 3

Air Canada flights from Seattle to Sydney

Our best Air Canada deals on Seattle to Sydney flight tickets
Air Canada
Feb 3
SEA8:00 pmSeattle/Tacoma Intl
18h 35m
1 stop
SYD9:35 amSydney Kingsford Smith
Feb 22
SYD11:20 amSydney Kingsford Smith
22h 11m
1 stop
SEA2:31 pmSeattle/Tacoma Intl
$911
Find similar
Air Canada
Feb 15
SEA8:00 pmSeattle/Tacoma Intl
18h 35m
1 stop
SYD9:35 amSydney Kingsford Smith
Feb 22
SYD11:20 amSydney Kingsford Smith
17h 11m
1 stop
SEA9:31 amSeattle/Tacoma Intl
$912
Find similar
Air Canada
Feb 10
SEA8:00 pmSeattle/Tacoma Intl
18h 35m
1 stop
SYD9:35 amSydney Kingsford Smith
Mar 10
SYD10:20 amSydney Kingsford Smith
17h 11m
1 stop
SEA9:31 amSeattle/Tacoma Intl
$927
Find similar

Qantas Airways flights from Seattle to Sydney

Our best Qantas Airways deals on Seattle to Sydney flight tickets
Qantas Airways
Jan 28
SEA3:57 pmSeattle/Tacoma Intl
27h 28m
2 stops
SYD2:25 pmSydney Kingsford Smith
Feb 8
SYD9:25 pmSydney Kingsford Smith
19h 33m
1 stop
SEA9:58 pmSeattle/Tacoma Intl
$903
Find similar
Qantas Airways
Feb 7
SEA12:59 pmSeattle/Tacoma Intl
23h 26m
1 stop
SYD7:25 amSydney Kingsford Smith
Feb 14
SYD5:50 pmSydney Kingsford Smith
44h 03m
2 stops
SEA6:53 pmSeattle/Tacoma Intl
$982
Find similar
Qantas Airways
Dec 31
SEA6:00 amSeattle/Tacoma Intl
32h 00m
1 stop
SYD9:00 amSydney Kingsford Smith
Feb 10
SYD7:15 pmSydney Kingsford Smith
41h 50m
2 stops
SEA6:05 pmSeattle/Tacoma Intl
$1,006
Find similar

momondo Fare Finder

 
Customize 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 832,500 searches. Data last updated December 10, 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

Wed 1/28

3:57 pm-2:25 pm

2 stops27h 28m

Sydney Kingsford Smith

Sun 2/8

9:25 pm-9:58 pm

1 stop19h 33m

$903

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 2/3

8:00 pm-9:35 am

1 stop18h 35m

Sydney Kingsford Smith

Sun 2/22

11:20 am-2:31 pm

1 stop22h 11m

$911

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 2/15

8:00 pm-9:35 am

1 stop18h 35m

Sydney Kingsford Smith

Sun 2/22

11:20 am-9:31 am

1 stop17h 11m

$912

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 5/12

4:30 pm-9:25 am

1 stop23h 55m

Sydney Kingsford Smith

Tue 5/26

11:50 am-8:48 pm

2 stops25h 58m

$921

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 5/12

5:45 pm-7:15 pm

2 stops32h 30m

Sydney Kingsford Smith

Tue 5/26

11:50 am-8:48 pm

2 stops25h 58m

$925

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Wed 4/8

3:40 pm-7:20 am

1 stop22h 40m

Sydney Kingsford Smith

Tue 4/21

6:30 am-3:03 pm

2 stops25h 33m

$926

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 2/10

8:00 pm-9:35 am

1 stop18h 35m

Sydney Kingsford Smith

Tue 3/10

10:20 am-9:31 am

1 stop17h 11m

$927

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 2/17

10:05 am-9:35 am

1 stop28h 30m

Sydney Kingsford Smith

Tue 3/10

10:20 am-7:16 pm

1 stop26h 56m

$929

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 1/20

8:00 pm-2:40 pm

2 stops23h 40m

Sydney Kingsford Smith

Tue 2/3

11:20 am-2:31 pm

1 stop22h 11m

$931

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 1/20

8:00 pm-4:40 pm

2 stops25h 40m

Sydney Kingsford Smith

Tue 2/3

11:20 am-7:16 pm

1 stop26h 56m

$932

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 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?

In general, August is the cheapest month to fly from Seattle to Sydney. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $846. If you are unable to visit Sydney during the month of August, then departing from Seattle during the month September is also very affordable. Most momondo users find prices during this month for around $878.

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

The cheapest day to depart from Seattle to Sydney is on a Tuesday when prices can be found for as low as $1,078. The most expensive day to fly to Sydney is Thursday, with ticket prices averaging around $1,156.

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 Seattle to Sydney in the evening for as low as $1,078. 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 in the morning, with an average ticket price of $1,152. Departure times in the morning 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 Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Sydney for around $1,062 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Sydney from Seattle for as low as $877 on momondo.

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 round-trip 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?

    Sydney Kingsford Smith is 7743.7 mi away from Seattle/Tacoma Intl. 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 are updated 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?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. 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 license 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
ANAPriceFrom $583Free CancellationRating
8.4
1,020 reviews
Search ANA flights
Alaska AirlinesPriceFrom $591Free CancellationRating
8.0
11,423 reviews
Search Alaska Airlines flights
Philippine AirlinesPriceFrom $758Free CancellationRating
7.3
940 reviews
Search Philippine Airlines flights
Air CanadaPriceFrom $779Free CancellationRating
7.1
10,513 reviews
Search Air Canada flights
Qantas AirwaysPriceFrom $789Free CancellationRating
7.5
947 reviews
Search Qantas Airways flights
American AirlinesPriceFrom $804Free CancellationRating
7.2
11,047 reviews
Search American Airlines flights
Hawaiian AirlinesPriceFrom $813Free CancellationRating
7.8
2,818 reviews
Search Hawaiian Airlines flights
United AirlinesPriceFrom $831Free CancellationRating
7.4
9,092 reviews
Search United Airlines flights
DeltaPriceFrom $842Free CancellationRating
7.9
8,007 reviews
Search Delta 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 Seattle to Sydney?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Seattle to Sydney. momondo saves you time and could save you money on your trip.

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

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

How can momondo help me find flights from Seattle 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 Seattle.

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

Yes. momondo can track prices for Seattle to Sydney flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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