Latest deals
Insights
When to book
FAQs
Reviews
Price Alerts

Cheap flights from Seattle to Sydney from $391

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 5/12. 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
0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from Seattle to Sydney

Cheap round-trip flights

Enter your travel dates to find the best prices.
Air Canada Logo
10:05 am - 9:35 am
SEA
-
SYD
28h 30m1 stop
Air Canada Logo
10:20 am - 9:33 am
SYD
-
SEA
17h 13m1 stop
$1,020Air Canada
Wed, Mar 4 - Wed, Apr 1
Multiple Airlines Logo
8:00 pm - 11:25 am
SEA
-
SYD
22h 25m2 stops
Multiple Airlines Logo
9:20 am - 7:18 pm
SYD
-
SEA
26h 58m1 stop
$1,021Multiple Airlines
Sun, Apr 5 - Mon, Apr 13
Air Canada Logo
10:05 am - 8:35 am
SEA
-
SYD
28h 30m1 stop
Air Canada Logo
10:20 am - 7:16 pm
SYD
-
SEA
26h 56m1 stop
$1,022Air Canada
Fri, Mar 13 - Sun, Mar 22
Air Canada Logo
3:40 pm - 9:35 am
SEA
-
SYD
22h 55m1 stop
Air Canada Logo
10:20 am - 7:16 pm
SYD
-
SEA
26h 56m1 stop
$1,024Air Canada
Fri, Feb 27 - Sun, Mar 22
Multiple Airlines Logo
8:00 pm - 2:40 pm
SEA
-
SYD
23h 40m2 stops
Multiple Airlines Logo
9:00 am - 9:15 am
SYD
-
SEA
19h 15m2 stops
$1,028Multiple Airlines
Fri, Jan 23 - Thu, Jan 29
Air Canada Logo
3:40 pm - 9:35 am
SEA
-
SYD
22h 55m1 stop
Air Canada Logo
10:20 am - 7:16 pm
SYD
-
SEA
26h 56m1 stop
$1,029Air Canada
Fri, Feb 27 - Sun, Mar 22
Air Canada Logo
3:40 pm - 6:05 pm
SEA
-
SYD
31h 25m2 stops
Air Canada Logo
11:20 am - 7:16 pm
SYD
-
SEA
26h 56m1 stop
$1,030Air Canada
Fri, Feb 13 - Sat, Feb 28
Multiple Airlines Logo
12:09 pm - 7:25 am
SEA
-
SYD
24h 16m1 stop
Multiple Airlines Logo
9:35 am - 7:58 pm
SYD
-
SEA
29h 23m2 stops
$1,031Multiple Airlines
Tue, Feb 10 - Wed, Mar 4
Multiple Airlines Logo
10:10 am - 7:20 am
SEA
-
SYD
28h 10m1 stop
Multiple Airlines Logo
6:00 am - 9:15 am
SYD
-
SEA
20h 15m2 stops
$1,032Multiple Airlines
Sat, Apr 18 - Mon, May 11
Air Canada Logo
8:00 pm - 9:35 am
SEA
-
SYD
18h 35m1 stop
Air Canada Logo
7:00 am - 9:31 am
SYD
-
SEA
20h 31m2 stops
$1,033Air Canada
Fri, Feb 27 - Sun, Mar 22

Qantas Airways flights from Seattle to Sydney

Our best Qantas Airways deals on Seattle to Sydney flight tickets
Qantas Airways
Jan 6
SEA3:49 pmSeattle/Tacoma Intl
19h 21m
1 stop
SYD6:10 amSydney Kingsford Smith
Feb 6
SYD8:45 amSydney Kingsford Smith
22h 44m
2 stops
SEA12:29 pmSeattle/Tacoma Intl
$1,050
Find similar
Qantas Airways
Feb 1
SEA3:45 pmSeattle/Tacoma Intl
19h 25m
1 stop
SYD6:10 amSydney Kingsford Smith
Feb 15
SYD9:25 pmSydney Kingsford Smith
19h 23m
1 stop
SEA9:48 pmSeattle/Tacoma Intl
$1,083
Find similar
Qantas Airways
Mar 13
SEA7:05 pmSeattle/Tacoma Intl
19h 55m
1 stop
SYD9:00 amSydney Kingsford Smith
Mar 22
SYD5:45 pmSydney Kingsford Smith
19h 08m
1 stop
SEA6:53 pmSeattle/Tacoma Intl
$1,085
Find similar

Air Canada flights from Seattle to Sydney

Our best Air Canada deals on Seattle to Sydney flight tickets
Air Canada
Mar 4
SEA10:05 amSeattle/Tacoma Intl
28h 30m
1 stop
SYD9:35 amSydney Kingsford Smith
Apr 1
SYD10:20 amSydney Kingsford Smith
17h 13m
1 stop
SEA9:33 amSeattle/Tacoma Intl
$1,020
Find similar
Air Canada
Mar 13
SEA10:05 amSeattle/Tacoma Intl
28h 30m
1 stop
SYD8:35 amSydney Kingsford Smith
Mar 22
SYD10:20 amSydney Kingsford Smith
26h 56m
1 stop
SEA7:16 pmSeattle/Tacoma Intl
$1,022
Find similar
Air Canada
Feb 27
SEA3:40 pmSeattle/Tacoma Intl
22h 55m
1 stop
SYD9:35 amSydney Kingsford Smith
Mar 22
SYD10:20 amSydney Kingsford Smith
26h 56m
1 stop
SEA7:16 pmSeattle/Tacoma Intl
$1,024
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 15, 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 3/4

10:05 am-9:35 am

1 stop28h 30m

Sydney Kingsford Smith

Wed 4/1

10:20 am-9:33 am

1 stop17h 13m

$1,020

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 4/5

8:00 pm-11:25 am

2 stops22h 25m

Sydney Kingsford Smith

Mon 4/13

9:20 am-7:18 pm

1 stop26h 58m

$1,021

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 3/13

10:05 am-8:35 am

1 stop28h 30m

Sydney Kingsford Smith

Sun 3/22

10:20 am-7:16 pm

1 stop26h 56m

$1,022

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 2/27

3:40 pm-9:35 am

1 stop22h 55m

Sydney Kingsford Smith

Sun 3/22

10:20 am-7:16 pm

1 stop26h 56m

$1,024

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 1/23

8:00 pm-2:40 pm

2 stops23h 40m

Sydney Kingsford Smith

Thu 1/29

9:00 am-9:15 am

2 stops19h 15m

$1,028

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 2/27

3:40 pm-9:35 am

1 stop22h 55m

Sydney Kingsford Smith

Sun 3/22

10:20 am-7:16 pm

1 stop26h 56m

$1,029

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 2/13

3:40 pm-6:05 pm

2 stops31h 25m

Sydney Kingsford Smith

Sat 2/28

11:20 am-7:16 pm

1 stop26h 56m

$1,030

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 2/10

12:09 pm-7:25 am

1 stop24h 16m

Sydney Kingsford Smith

Wed 3/4

9:35 am-7:58 pm

2 stops29h 23m

$1,031

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 4/18

10:10 am-7:20 am

1 stop28h 10m

Sydney Kingsford Smith

Mon 5/11

6:00 am-9:15 am

2 stops20h 15m

$1,032

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 2/27

8:00 pm-9:35 am

1 stop18h 35m

Sydney Kingsford Smith

Sun 3/22

7:00 am-9:31 am

2 stops20h 31m

$1,033

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

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 $1,067 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

17h 45m

Direct flights

None
The fastest flight from Seattle to Sydney takes 17h 45m
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 17h 45m.

  • 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
1,023 reviews
Search ANA flights
Alaska AirlinesPriceFrom $591Free CancellationRating
8.0
11,452 reviews
Search Alaska Airlines flights
Philippine AirlinesPriceFrom $758Free CancellationRating
7.3
942 reviews
Search Philippine Airlines flights
Air CanadaPriceFrom $779Free CancellationRating
7.1
10,526 reviews
Search Air Canada flights
Qantas AirwaysPriceFrom $789Free CancellationRating
7.5
946 reviews
Search Qantas Airways flights
American AirlinesPriceFrom $804Free CancellationRating
7.2
11,048 reviews
Search American Airlines flights
Hawaiian AirlinesPriceFrom $813Free CancellationRating
7.8
2,819 reviews
Search Hawaiian Airlines flights
United AirlinesPriceFrom $831Free CancellationRating
7.4
9,092 reviews
Search United Airlines flights
DeltaPriceFrom $842Free CancellationRating
7.9
8,008 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.

An easier way to manage your Sydney trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Wed 1/14
Wed 1/21
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Australia