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
20 Dec — 27 Dec1
Return
1 adult
Economy
Return
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 25 days in advance, depart on a Monday or Wednesday and return on a Thursday
Find flight deals from Seattle to Sydney
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 20 November 2025.
Sun 23/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Fri 5/1206:20SYD - SEA
2 stops22h 11mMultiple Airlines
Deal found 18/11$1,513
Wed 31/1206:00SEA - SYD
1 stop32h 00mQantas Airways
Tue 10/207:05SYD - SEA
2 stops24h 24mQantas Airways
Deal found 18/11$1,524
Sun 21/1206:00SEA - SYD
1 stop32h 00mQantas Airways
Fri 16/119:15SYD - SEA
2 stops43h 07mQantas Airways
Deal found 18/11$1,558
Wed 31/1220:00SEA - SYD
1 stop18h 35mAir Canada
Tue 10/211:20SYD - SEA
1 stop17h 11mAir Canada
Deal found 18/11$1,566
Sun 30/1115:40SEA - SYD
1 stop22h 55mAir Canada
Sun 14/1211:20SYD - SEA
1 stop22h 11mAir Canada
Deal found 20/11$1,601
Sun 30/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Sun 14/1207:05SYD - SEA
2 stops29h 23mMultiple Airlines
Deal found 19/11$1,626
Best flights from Seattle to Sydney
Discover carefully curated flight deals from Seattle to Sydney that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 20 November 2025.
Mon 2/217:12SEA - SYD
1 stop20h 53mUnited Airlines
Tue 17/212:10SYD - SEA
1 stop27h 51mUnited Airlines
Deal found 19/11$1,777
Wed 4/207:00SEA - SYD
1 stop17h 45mAlaska Airlines
Thu 19/221:40SYD - SEA
1 stop17h 46mAlaska Airlines
Deal found 19/11$1,789
Wed 31/1205:25SEA - SYD
2 stops32h 05mDelta
Tue 10/214:15SYD - SEA
2 stops23h 14mDelta
Deal found 20/11$1,797
Wed 4/212:24SEA - SYD
1 stop25h 41mUnited Airlines
Mon 16/212:10SYD - SEA
1 stop18h 08mUnited Airlines
Deal found 19/11$1,777
Thu 23/408:00SEA - SYD
1 stop18h 45mAlaska Airlines
Sat 9/521:40SYD - SEA
1 stop18h 18mAlaska Airlines
Deal found 17/11$1,789
Sun 1/313:38SEA - SYD
2 stops23h 52mDelta
Tue 17/313:15SYD - SEA
2 stops21h 45mDelta
Deal found 19/11$1,799
Tue 3/209:25SEA - SYD
1 stop25h 55mUnited Airlines
Tue 17/214:00SYD - SEA
1 stop20h 41mUnited Airlines
Deal found 19/11$1,777
Thu 5/207:00SEA - SYD
1 stop17h 45mAlaska Airlines
Thu 19/221:40SYD - SEA
1 stop21h 00mAlaska Airlines
Deal found 19/11$1,789
Tue 6/113:30SEA - SYD
1 stop24h 00mDelta
Tue 27/114:15SYD - SEA
2 stops28h 54mDelta
Deal found 19/11$1,799
Mon 27/408:00SEA - SYD
1 stop18h 45mAlaska Airlines
Sat 9/521:40SYD - SEA
1 stop18h 18mAlaska Airlines
Deal found 17/11$1,789
Tue 6/113:38SEA - SYD
2 stops23h 52mDelta
Wed 14/110:40SYD - SEA
2 stops31h 42mDelta
Deal found 18/11$1,799
Fri 30/119:30SEA - SYD
1 stop18h 45mUnited Airlines
Wed 18/212:10SYD - SEA
1 stop18h 08mUnited Airlines
Deal found 19/11$1,854
Last-minute flights from Seattle to Sydney
Discover last-minute flight deals from Seattle to Sydney. Data last updated 20 November 2025 and is based on user searches.
Fri 28/1120:00SEA - SYD
1 stop18h 35mAir Canada
Mon 8/1219:15SYD - SEA
2 stops33h 16mAir Canada
Deal found 20/11$1,754
Fri 28/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Mon 8/1216:00SYD - SEA
1 stop22h 16mMultiple Airlines
Deal found 20/11$1,768
Sun 30/1110:05SEA - SYD
1 stop28h 30mAir Canada
Sun 14/1211:20SYD - SEA
1 stop17h 11mAir Canada
Deal found 20/11$1,601
Sun 30/1121:30SEA - SYD
1 stop41h 20mMultiple Airlines
Sun 14/1207:05SYD - SEA
2 stops29h 23mMultiple Airlines
Deal found 19/11$1,626
Sun 30/1100:10SEA - SYD
2 stops35h 25mMultiple Airlines
Wed 10/1221:00SYD - SEA
2 stops30h 05mMultiple Airlines
Deal found 19/11$2,235
One-way flights from Seattle to Sydney
Search for one-way flight options from Seattle to Sydney. Find affordable one-way fares based on user searches. Data last updated 20 November 2025.
Sun 15/322:30SEA - SYD
1 stop41h 20mPhilippine Airlines
Deal found 19/11$583
Wed 25/322:30SEA - SYD
1 stop41h 20mPhilippine Airlines
Deal found 18/11$585
Thu 30/423:05SEA - SYD
1 stop41h 40mPhilippine Airlines
Deal found 20/11$605
Tue 28/423:05SEA - SYD
1 stop41h 40mPhilippine Airlines
Deal found 20/11$626
Fri 1/523:05SEA - SYD
1 stop41h 40mPhilippine Airlines
Deal found 20/11$668
Mon 23/210:29SEA - SYD
2 stops31h 06mMultiple Airlines
Deal found 18/11$671
Sat 21/220:41SEA - SYD
2 stops44h 54mMultiple Airlines
Deal found 18/11$676
Sat 7/320:41SEA - SYD
2 stops44h 54mMultiple Airlines
Deal found 20/11$690
Sun 22/210:29SEA - SYD
2 stops31h 06mMultiple Airlines
Deal found 18/11$694
Tue 28/400:10SEA - SYD
2 stops40h 35mMultiple Airlines
Deal found 20/11$713
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 20 November 2025.
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 20 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
Mon 2/2
17:12-09:05
1 stop20h 53m
Sydney Kingsford Smith
Tue 17/2
12:10-21:01
1 stop27h 51m
$1,777
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Wed 4/2
12:24-09:05
1 stop25h 41m
Sydney Kingsford Smith
Mon 16/2
12:10-11:18
1 stop18h 08m
$1,777
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Tue 3/2
09:25-06:20
1 stop25h 55m
Sydney Kingsford Smith
Tue 17/2
14:00-15:41
1 stop20h 41m
$1,777
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Wed 4/2
07:00-19:45
1 stop17h 45m
Sydney Kingsford Smith
Thu 19/2
21:40-20:26
1 stop17h 46m
$1,789
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Thu 23/4
08:00-19:45
1 stop18h 45m
Sydney Kingsford Smith
Sat 9/5
21:40-22:58
1 stop18h 18m
$1,789
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Thu 5/2
07:00-19:45
1 stop17h 45m
Sydney Kingsford Smith
Thu 19/2
21:40-23:40
1 stop21h 00m
$1,789
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Mon 27/4
08:00-19:45
1 stop18h 45m
Sydney Kingsford Smith
Sat 9/5
21:40-22:58
1 stop18h 18m
$1,789
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Wed 31/12
05:25-08:30
2 stops32h 05m
Sydney Kingsford Smith
Tue 10/2
14:15-18:29
2 stops23h 14m
$1,797
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Sun 1/3
13:38-08:30
2 stops23h 52m
Sydney Kingsford Smith
Tue 17/3
13:15-17:00
2 stops21h 45m
$1,799
SeattleSydney
SEA - SYD
SEASYD
Seattle/Tacoma Intl
Tue 6/1
13:30-08:30
1 stop24h 00m
Sydney Kingsford Smith
Tue 27/1
14:15-00:09
2 stops28h 54m
$1,799
Flights are sorted by cheapest return flights first.
Deals found on 18/11
Showing 1-10 of 24 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
Prices
More
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 14 November 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 25 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 $825). Flying from Seattle to Sydney in December is currently the most expensive (average of $1,303). 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 20 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.
What’s the top stopover airport for flights from Seattle to Sydney?
Share of one-stop return flights from Seattle to Sydney chosen by Cheapflights users in the past 12 months, using the same stopover each way.
Vancouver (YVR) – chosen by Cheapflights users on 35% of one-stop itineraries from Seattle to Sydney on Cheapflights.
What’s the cheapest stopover airport for flights from Seattle to Sydney?
Average return fare for one-stop flights from Seattle to Sydney, chosen by Cheapflights users in the past 12 months, with the same stopover each way.
San Francisco (SFO) is the most affordable one-stop option, with an average return flight price of $1,760.
What’s the fastest stopover option from Seattle to Sydney?
Shortest average travel time for one-stop one-way flights from Seattle to Sydney, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.
Flights via San Francisco (SFO) have the shortest average one-way travel time for one-stop routes: 18h 46m.
Which airport typically offers the quickest stopover for flights from Seattle to Sydney?
Average stopover duration for one-stop one-way flights from Seattle to Sydney, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.
Flights via San Francisco (SFO) offer the fastest connection on this route, with an average stopover time of 1h 54m.
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 20 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.
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
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
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?
United Airlines and Alaska Airlines can get you from Seattle to Sydney in just under 17h 45m. Your travel time can differ by up to 3h 08m. 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 $1,232. Another option worth looking into is Air Canada, starting at $1,296 round trip. Users have found that United Airlines is 24% cheaper than the other options available to this destination.
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 $825). Flying from Seattle to Sydney in December is currently the most expensive (average of $1,303). 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.
Explore flights to Sydney departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 20 November 2025.
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 20 November 2025.
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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