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Cheap flights from Seattle to Sydney from $627

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 15/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — SYD
5 Dec — 12 Dec1
1 adult
1 adult, Economy, 0 bags

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Sydney Kingsford Smith are usually found in August or September, booked 47 days in advance, depart on a Monday or Wednesday and return on a Thursday

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Enter your travel dates to find the best prices.

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 5 November 2025.

Thu 27/1115:22SEA - SYD
2 stops26h 13mMultiple Airlines
Mon 1/1214:00SYD - SEA
2 stops25h 58mMultiple Airlines
Deal found 4/11$1,549
Wed 26/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Thu 4/1221:40SYD - SEA
2 stops28h 22mMultiple Airlines
Deal found 4/11$1,576
Wed 5/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Wed 12/1114:00SYD - SEA
2 stops22h 05mMultiple Airlines
Deal found 4/11$1,582
Tue 25/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Thu 4/1221:40SYD - SEA
2 stops28h 22mMultiple Airlines
Deal found 4/11$1,606
Tue 2/1210:05SEA - SYD
1 stop25h 50mMultiple Airlines
Tue 9/1207:05SYD - SEA
2 stops21h 26mMultiple Airlines
Deal found 2/11$1,620
Mon 10/1117:30SEA - SYD
2 stops24h 05mMultiple Airlines
Fri 21/1114:00SYD - SEA
2 stops21h 48mMultiple Airlines
Deal found 4/11$1,623
Tue 25/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Wed 3/1206:00SYD - SEA
2 stops27h 24mMultiple Airlines
Deal found 4/11$1,628
Wed 26/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Tue 2/1221:40SYD - SEA
1 stop36h 00mMultiple Airlines
Deal found 4/11$1,629
Tue 25/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Tue 2/1221:40SYD - SEA
1 stop36h 00mMultiple Airlines
Deal found 4/11$1,636

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 5 November 2025.

Round-trip from

$1,485

One-way from

$627

Popular in

December

Cheapest in

August

Average price

$1,509
Philippine Airlines
  • Philippine Airlines
  • 15/2-24/2
  • 2 total stops
  • 67h 25m total
  • Seattle to Sydney
Search Deals
Philippine Airlines
  • Philippine Airlines
  • 15/3
  • 1 total stop
  • 41h 20m total
  • Seattle to Sydney
Search Deals
Highest demand for flights based on searches. 12% potential increase in price ($360 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($61 potential savings vs. average return price).
Search Deals
Average for round-trip flights in November 2025
Search Deals

Cheapflights 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, Cheapflights users made 647,157 searches. Data last updated 5 November 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 8/3

15:40-19:45

1 stop34h 05m

Sydney Kingsford Smith

Thu 12/3

21:40-21:15

1 stop17h 35m

$1,809

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 30/12

19:12-09:15

1 stop19h 03m

Sydney Kingsford Smith

Tue 27/1

11:20-16:29

1 stop24h 09m

$1,938

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 30/12

13:35-09:15

1 stop24h 40m

Sydney Kingsford Smith

Sun 25/1

14:00-15:44

1 stop20h 44m

$1,938

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Wed 31/12

19:12-09:15

1 stop19h 03m

Sydney Kingsford Smith

Tue 10/2

11:20-21:12

2 stops28h 52m

$1,938

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 18/11

12:00-09:05

2 stops26h 05m

Sydney Kingsford Smith

Sat 29/11

12:10-12:18

1 stop19h 08m

$1,941

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sun 8/3

09:40-07:25

2 stops27h 45m

Sydney Kingsford Smith

Thu 12/3

13:15-17:00

2 stops21h 45m

$1,949

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 9/12

05:00-09:05

2 stops33h 05m

Sydney Kingsford Smith

Sat 27/12

11:50-21:17

2 stops28h 27m

$1,949

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Mon 29/12

19:12-06:20

1 stop40h 08m

Sydney Kingsford Smith

Tue 27/1

12:10-11:30

1 stop18h 20m

$1,951

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 3/1

07:00-19:45

1 stop17h 45m

Sydney Kingsford Smith

Thu 22/1

21:40-21:02

1 stop18h 22m

$1,969

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Tue 6/1

07:00-19:45

1 stop17h 45m

Sydney Kingsford Smith

Tue 27/1

21:40-06:44

2 stops28h 04m

$1,969

Flights are sorted by cheapest return flights first.

Deals found on 2/11

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 return 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 return flight from Seattle to Sydney. Price data was last updated on 31 October 2025.

The price you pay for your flight from Seattle to Sydney may vary depending on when you book. For the best chance of a lower fare, look to book 47 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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

Currently, July is the cheapest month in which you can book a flight from Seattle to Sydney (average of $839). Flying from Seattle to Sydney in January is currently the most expensive (average of $1,310). 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 5 November 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Sydney in the afternoon. If you’re flexible enough to do this you can expect to save up to 26% on your trip compared to booking a flight at midday.

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 5 November 2025.
Get a feel of what it's like to fly with United Airlines and Air Canada from Seattle to Sydney by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
9,002 reviews
Check prices

Boarding

7.7

Overall

7.4

Comfort

7.3

Entertainment

7.1

Crew

8.1

Food

6.6

Reviews

1 / 20
2.0
Mediocre

Sebrena,Oct 2025

IAH - RSW

The worst that I have ever experienced in my life so bad if it was free I'm not ever going to use your Airline again I dont believe ..... very disappointed 😞 😔0000000000000
United Airlines
7.4
Good
9,002 reviews
United Airlines
7.4
Good
9,002 reviews
Check prices

Boarding

7.7

Overall

7.4

Comfort

7.3

Entertainment

7.1

Crew

8.1

Food

6.6

Reviews

1 / 20
2.0
Mediocre

Sebrena,Oct 2025

IAH - RSW

The worst that I have ever experienced in my life so bad if it was free I'm not ever going to use your Airline again I dont believe ..... very disappointed 😞 😔0000000000000
Air Canada
7.1
Good
10,403 reviews
United Airlines
7.4
Good
9,002 reviews
Check prices

Boarding

7.7

Overall

7.4

Comfort

7.3

Entertainment

7.1

Crew

8.1

Food

6.6

Reviews

1 / 20
2.0
Mediocre

Sebrena,Oct 2025

IAH - RSW

The worst that I have ever experienced in my life so bad if it was free I'm not ever going to use your Airline again I dont believe ..... very disappointed 😞 😔0000000000000

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?

    Alaska Airlines and United Airlines can get you from Seattle to Sydney in just under 19h 03m. Your travel time can differ by up to 15h 02m. Airlines will cover a distance of 12463 km. Both multi-stop and direct flights can be found to your destination and back.

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

    Flying on United Airlines is currently your cheapest option to Sydney, with prices starting at $1,228. Another option worth looking into is Air Canada, starting at $1,292 round trip. Users have found that United Airlines is 24% cheaper than the other options available to this destination.

  • 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 holiday 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, July is the cheapest month in which you can book a flight from Seattle to Sydney (average of $839). Flying from Seattle to Sydney in January is currently the most expensive (average of $1,310). 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

Travelling to a place near Sydney?

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

Browse thousands of different options on Cheapflights for your next trip

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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
Spokane to Sydney flights
Portland to Coolangatta flights

Top 2 airlines flying from Seattle to Sydney

Discover the top 2 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 647,157 searches. Data last updated 5 November 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$1,228Average$2,226FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Air CanadaCheapest$1,292Average$1,769FlexibilityNo cancel feeOn-time67%
Search Air Canada flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Seattle to Sydney?

Deals for Seattle to Sydney flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Seattle to Sydney?

Millions of users choose and trust Cheapflights to book the best flight deals from Seattle to Sydney for free. We help you search and compare prices from hundreds of airlines for the right flight just for you.

Can Cheapflights find flights from Seattle to Sydney with no change fees?

Need flexible booking options for your flight to Sydney from Seattle? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

Can Cheapflights notify me if prices for flights from Seattle to Sydney become cheaper?

Yes, Cheapflights offers price alerts on Seattle to Sydney flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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