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$366+ Cheap flights from Seattle (SEA) to Sydney (SYD)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/11. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — SYD
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Sydney Kingsford Smith are usually found in February or March, booked 2 days in advance, depart on a Tuesday or Wednesday and return on a Saturday

Cheap flight deals from Seattle to Sydney

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Sydney (SYD). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 11, 2025.

Round-trip from

$814
(Air Canada)

One-way from

$366
(Air Canada)

Popular in

December

Cheapest in

February

Average price

$1,051
From Seattle/Tacoma Intl to Sydney Kingsford Smith
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One-way flight from Seattle/Tacoma Intl to Sydney Kingsford Smith
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Highest demand for flights based on searches. 11% potential increase in price ($148 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($26 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Seattle to Sydney

Cheapest flights from Seattle to Sydney
Explore the most affordable flight options available from Seattle to Sydney. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

This Air Canada deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/192:55 pmSEA - SYD
2 stops26h 45mAir Canada
Sun 10/267:00 amSYD - SEA
2 stops20h 31mAir Canada
Deal found 9/11$814
This American Airlines deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/203:23 pmSEA - SYD
1 stop23h 07mAmerican Airlines
Wed 10/19:10 amSYD - SEA
1 stop22h 39mAmerican Airlines
Deal found 9/9$815
This American Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/213:23 pmSEA - SYD
1 stop23h 07mAmerican Airlines
Sun 10/56:45 pmSYD - SEA
1 stop21h 13mAmerican Airlines
Deal found 9/10$816
This Flighttix deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Flighttix is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/257:44 amSEA - SYD
1 stop18h 01mHawaiian Airlines
Tue 10/289:40 pmSYD - SEA
1 stop19h 52mHawaiian Airlines
Deal found 9/9$819
This Orbitz deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/88:00 pmSEA - SYD
2 stops23h 40mAir Canada
Sat 11/153:00 pmSYD - SEA
2 stops37h 31mAir Canada
Deal found 9/11$820
This FlightHub deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/135:50 amSEA - SYD
2 stops41h 15mAir Canada
Thu 12/2511:20 amSYD - SEA
1 stop17h 11mAir Canada
Deal found 9/9$825
This Priceline deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/164:59 pmSEA - SYD
1 stop21h 06mQantas Airways
Tue 9/239:10 amSYD - SEA
1 stop20h 44mQantas Airways
Deal found 9/11$826
This Alaska Airlines deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/177:44 amSEA - SYD
1 stop18h 01mAlaska Airlines
Tue 11/49:40 pmSYD - SEA
2 stops20h 56mAlaska Airlines
Deal found 9/8$827
This Alaska Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/56:59 pmSEA - SYD
2 stops29h 46mAlaska Airlines
Sat 11/159:40 pmSYD - SEA
1 stop20h 41mAlaska Airlines
Deal found 9/11$828
This Air Canada deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/135:50 amSEA - SYD
1 stop30h 05mAir Canada
Tue 12/2311:20 amSYD - SEA
1 stop26h 56mAir Canada
Deal found 9/9$829
This Air Canada deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/118:00 pmSEA - SYD
1 stop18h 35mAir Canada
Tue 11/1811:20 amSYD - SEA
1 stop29h 46mAir Canada
Deal found 9/11$830
This American Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/202:42 pmSEA - SYD
1 stop23h 23mAmerican Airlines
Wed 11/511:20 amSYD - SEA
2 stops21h 48mAmerican Airlines
Deal found 9/10$831

Cheapflights 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, Cheapflights users made 2,558,603 searches. Data last updated September 11, 2025.
Use the filters below to find and compare flights from Seattle to Sydney that are best for you.

Fly from

Seattle

Fly to

Sydney

Route

Depart

Return

Price

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 11/9

4:30 pm-7:25 am

1 stop19h 55m

Sydney Kingsford Smith

Fri 11/28

5:45 pm-6:11 pm

1 stop19h 26m

$827

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Wed 11/12

7:00 am-7:45 pm

1 stop17h 45m

Sydney Kingsford Smith

Fri 11/21

9:40 pm-11:17 pm

1 stop20h 37m

$827

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 11/9

4:30 pm-7:25 am

1 stop19h 55m

Sydney Kingsford Smith

Sun 11/23

5:45 pm-6:11 pm

1 stop19h 26m

$827

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Thu 11/6

7:00 am-7:45 pm

1 stop17h 45m

Sydney Kingsford Smith

Fri 11/21

9:40 pm-8:49 pm

1 stop18h 09m

$828

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 11/7

7:00 am-7:45 pm

1 stop17h 45m

Sydney Kingsford Smith

Thu 11/20

9:40 pm-5:35 am

1 stop26h 55m

$828

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 9/30

5:26 pm-7:00 am

1 stop20h 34m

Sydney Kingsford Smith

Wed 10/15

10:30 am-9:15 pm

2 stops28h 45m

$843

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 9/21

5:40 pm-6:35 am

1 stop19h 55m

Sydney Kingsford Smith

Tue 9/30

9:25 am-12:45 pm

1 stop20h 20m

$844

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Thu 11/6

7:28 pm-9:15 am

1 stop18h 47m

Sydney Kingsford Smith

Wed 11/19

11:50 am-6:10 pm

2 stops25h 20m

$844

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 9/21

5:35 pm-6:55 am

1 stop20h 20m

Sydney Kingsford Smith

Thu 10/2

9:30 am-9:15 pm

2 stops28h 45m

$844

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 12/13

5:05 am-9:05 am

2 stops33h 00m

Sydney Kingsford Smith

Fri 12/26

12:10 pm-5:00 pm

1 stop23h 50m

$848

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/10

Showing 1-10 of 22 results
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Best time to book a flight from Seattle to Sydney

Have a flexible travel schedule? Discover the best time to fly to Sydney from Seattle with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Sydney

How far ahead should I book a flight from Seattle to Sydney?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Sydney. Price data was last updated on August 29, 2025.

To ensure you get the cheapest price possible for a flight from Seattle to Sydney, you should look to book at least 2 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Seattle to Sydney?

Currently, February is the cheapest month in which you can book a flight from Seattle to Sydney (average of $1,035). Flying from Seattle to Sydney in December is currently the most expensive (average of $1,626). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to SYD?

Find hourly flight availability from Seattle to Sydney. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 11, 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Sydney in the evening. If you’re flexible enough to do this you can expect to save up to 7% on your trip compared to booking a flight in the morning.

What is the cheapest day to fly from Seattle to Sydney?

Use this chart to determine the cheapest time to fly round-trip from Seattle to Sydney. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Seattle to Sydney flight should consider departing on Tuesday evenings when fares are most often at their lowest. Thursday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Reviews of airlines servicing Sydney

Get insights into the airlines that provide service to Sydney. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Sydney. Reviews last updated September 11, 2025.
Read reviews from past customers who have flown Alaska Airlines, Delta, and Hawaiian Airlines from Seattle to Sydney. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Boarding

8.1

Overall

8.0

Entertainment

7.0

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Boarding

8.1

Overall

8.0

Entertainment

7.0

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Delta
8.0
Very good
7,960 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Boarding

8.1

Overall

8.0

Entertainment

7.0

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Hawaiian Airlines
7.8
Good
2,723 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Boarding

8.1

Overall

8.0

Entertainment

7.0

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
United Airlines
7.4
Good
8,937 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Boarding

8.1

Overall

8.0

Entertainment

7.0

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Air Canada
7.1
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Boarding

8.1

Overall

8.0

Entertainment

7.0

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Sydney. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Seattle to Sydney?

    Departing from Seattle to Sydney will take you 17h 45m. The distance between Seattle and Sydney is about 7744 mi.

  • What are the cheapest airlines flying from Seattle to Sydney round-trip?

    Cheapflights users have booked flights from Seattle to Sydney round-trip from $591. Other airlines that can offer you cheap pricing are Qantas Airways, from $789, and Air Canada, from $790. These flights start at 46% lower than the current average price 3 months from now.

  • Where are the most common layover locations when flying from Seattle to Sydney?

    The most popular layover on flights from Seattle to Sydney is Los Angeles. Vancouver sees the second most layovers for non-direct flights flying from Seattle to Sydney.

  • What are some popular things to do or see while on a layover in Los Angeles?

    Hollywood Bowl, Hollywood Walk of Fame, and The Wiltern are currently the most popular points of interest in Los Angeles at the moment. Hollywood Bowl, Hollywood Walk of Fame and The Wiltern are located about 12.5 mi, 11.7 mi, and 10.0 mi, respectively from Los Angeles if you are interested in checking them out. Travelers in need of a car in Los Angeles can rent one for about $49 per day.

  • What are some popular points of interest to see during a layover in Vancouver?

    Orpheum Theatre, Pacific Central Station, and Capilano Suspension Bridge are currently the most popular points of interest in Vancouver at the moment. Those on a layover in Vancouver interested in visiting Orpheum Theatre, Pacific Central Station, or Capilano Suspension Bridge can do so by traveling 6.5 mi, 6.6 mi, and 10.6 mi, respectively from Vancouver Intl. Those looking to explore during their layover in Vancouver can rent a car from Vancouver Intl for about $56 per day.

  • Where are the least popular layover locations for Seattle to Sydney flights?

    Seattle to Sydney flights have a layover in Honolulu the least frequently. Honolulu is followed by San Francisco in terms of the least popular layover location on flights from Seattle to Sydney.

  • Can I find deals for flights from Seattle to Sydney that include hotel bookings?

    Yes. In addition to deals on Seattle to Sydney flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Sydney?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Sydney.

  • Can I find deals for business class flights from Seattle to Sydney?

    Yes. Cheapflights offers flight deals from Seattle to Sydney by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to Sydney?

    Currently, February is the cheapest month in which you can book a flight from Seattle to Sydney (average of $1,035). Flying from Seattle to Sydney in December is currently the most expensive (average of $1,626). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Sydney?

Book flights to Sydney if you plan to visit one of these locations
Parramatta
Wollongong
Manly
Coogee

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Alternative routes for Seattle to Sydney

See prices for flight routes from nearby airports that may be better suited for you.
Portland to Sydney flights
Seattle to Coolangatta flights
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Top 8 airlines flying from Seattle to Sydney

Discover the top 8 airlines that operate flights from Seattle to Sydney. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
Alaska AirlinesCheapest$591Average$1,165FlexibilityNo cancel feeOn-time75%
Qantas AirwaysCheapest$789Average$908FlexibilityNo cancel feeOn-time74%
Air CanadaCheapest$790Average$1,062FlexibilityNo cancel feeOn-time67%
ANACheapest$794Average$1,083FlexibilityNo cancel feeOn-time80%
American AirlinesCheapest$804Average$1,034FlexibilityNo cancel feeOn-time71%
Hawaiian AirlinesCheapest$826Average$1,162FlexibilityNo cancel feeOn-time85%
United AirlinesCheapest$836Average$1,118FlexibilityNo cancel feeOn-time69%
DeltaCheapest$842Average$1,070FlexibilityNo cancel feeOn-timeN/A

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