HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Sydney

$390+ 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 3/18. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — SYD
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Seattle to Sydney with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Sydney Kingsford Smith are usually found in August or September, booked 50 days in advance, depart on a Tuesday or Wednesday and return on a Saturday

Cheap 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 December 12, 2025.

This Justfly.com deal was found by Cheapflights users on 12/11. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/316:00 amSEA - SYD
1 stop32h 00mQantas Airways
Tue 2/107:15 pmSYD - SEA
2 stops41h 50mQantas Airways
Deal found 12/11$1,009
This Travelocity deal was found by Cheapflights users on 12/10. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/313:40 pmSEA - SYD
1 stop22h 55mAir Canada
Tue 2/1011:20 amSYD - SEA
1 stop17h 11mAir Canada
Deal found 12/10$1,132
This Air Canada deal was found by Cheapflights users on 12/11. 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.
Sat 12/273:40 pmSEA - SYD
1 stop22h 55mAir Canada
Sat 1/177:15 pmSYD - SEA
2 stops33h 16mAir Canada
Deal found 12/11$1,145
This Air Canada deal was found by Cheapflights users on 12/10. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/123:40 pmSEA - SYD
2 stops47h 50mAir Canada
Tue 12/2311:20 amSYD - SEA
1 stop26h 56mAir Canada
Deal found 12/10$1,264
This United Airlines deal was found by Cheapflights users on 12/10. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/147:00 amSEA - SYD
1 stop28h 20mUnited Airlines
Tue 12/168:30 amSYD - SEA
2 stops35h 20mUnited Airlines
Deal found 12/10$1,291
This Booking.com deal was found by Cheapflights users on 12/10. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/108:00 pmSEA - SYD
1 stop39h 55mAir Canada
Wed 12/1711:20 amSYD - SEA
1 stop30h 26mAir Canada
Deal found 12/10$1,308
This Gotogate deal was found by Cheapflights users on 12/10. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/108:00 pmSEA - SYD
1 stop39h 55mMultiple Airlines
Wed 12/178:20 amSYD - SEA
2 stops20h 11mMultiple Airlines
Deal found 12/10$1,332

Find 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 December 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$988
(Air Canada)

One-way from

$390
(Trip.com)

Popular in

December

Cheapest in

August

Average price

$1,479
Provider with most accurate pricing for Seattle/Tacoma Intl-Sydney Kingsford Smith flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Sydney Kingsford Smith flights.
Search Deals
From Seattle/Tacoma Intl to Sydney Kingsford Smith
Search Deals
One-way flight from Seattle/Tacoma Intl to Sydney Kingsford Smith
Search Deals
Highest demand for flights based on searches. 14% potential increase in price ($180 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($39 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

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 December 12, 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

Sat 4/18

7:08 pm-7:05 am

1 stop18h 57m

Sydney Kingsford Smith

Mon 5/11

5:50 pm-10:49 pm

1 stop21h 59m

$1,096

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Mon 2/2

11:17 am-8:30 am

1 stop26h 13m

Sydney Kingsford Smith

Wed 2/18

10:40 am-12:58 pm

1 stop21h 18m

$1,113

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Wed 2/4

1:38 pm-8:30 am

2 stops23h 52m

Sydney Kingsford Smith

Tue 2/17

10:40 am-12:33 pm

2 stops20h 53m

$1,118

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Mon 2/2

3:57 pm-9:00 am

1 stop22h 03m

Sydney Kingsford Smith

Sat 2/14

11:20 am-6:57 pm

1 stop26h 37m

$1,148

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 1/31

6:00 am-9:00 am

1 stop32h 00m

Sydney Kingsford Smith

Thu 2/19

11:20 am-6:57 pm

1 stop26h 37m

$1,157

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 1/30

7:30 pm-9:15 am

1 stop18h 45m

Sydney Kingsford Smith

Wed 2/18

12:10 pm-11:18 am

1 stop18h 08m

$1,163

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 1/30

7:30 pm-9:15 am

1 stop18h 45m

Sydney Kingsford Smith

Tue 2/17

12:10 pm-11:18 am

1 stop18h 08m

$1,163

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Fri 1/30

11:17 am-8:30 am

1 stop26h 13m

Sydney Kingsford Smith

Tue 2/17

10:40 am-10:17 am

1 stop18h 37m

$1,163

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Sat 4/4

12:55 pm-7:00 am

2 stops25h 05m

Sydney Kingsford Smith

Sun 4/12

9:30 am-7:38 pm

1 stop27h 08m

$1,167

SeattleSydney

SEA - SYD

SEASYD

Seattle/Tacoma Intl

Wed 2/4

3:45 pm-12:35 pm

2 stops25h 50m

Sydney Kingsford Smith

Sun 2/15

2:00 pm-6:40 pm

2 stops23h 40m

$1,199

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/11

Showing 1-10 of 21 results
1
2
3

Compare providers for flights from Seattle to Sydney

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Sydney in December.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
AranGrantPrice Accuracy2 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Seattle-Sydney flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Seattle-Sydney flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Seattle-Sydney flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Sydney flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Sydney flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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 December 5, 2025.

To ensure you get the cheapest price possible for a flight from Seattle to Sydney, you should look to book at least 50 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, July is the cheapest month in which you can book a flight from Seattle to Sydney (average of $501). Flying from Seattle to Sydney in December is currently the most expensive (average of $845). 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 December 12, 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 6% 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 December 12, 2025.
Read reviews from past customers who have flown Alaska Airlines, Delta, and Qantas Airways 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
11,431 reviews

Food

7.1

Overall

8.0

Boarding

8.1

Comfort

7.8

Entertainment

7.0

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Alaska Airlines
8.0
Very good
11,431 reviews
Alaska Airlines
8.0
Very good
11,431 reviews

Food

7.1

Overall

8.0

Boarding

8.1

Comfort

7.8

Entertainment

7.0

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Delta
7.9
Good
8,005 reviews
Alaska Airlines
8.0
Very good
11,431 reviews

Food

7.1

Overall

8.0

Boarding

8.1

Comfort

7.8

Entertainment

7.0

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Qantas Airways
7.5
Good
947 reviews
Alaska Airlines
8.0
Very good
11,431 reviews

Food

7.1

Overall

8.0

Boarding

8.1

Comfort

7.8

Entertainment

7.0

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
United Airlines
7.4
Good
9,095 reviews
Alaska Airlines
8.0
Very good
11,431 reviews

Food

7.1

Overall

8.0

Boarding

8.1

Comfort

7.8

Entertainment

7.0

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Air Canada
7.1
Good
10,515 reviews
Alaska Airlines
8.0
Very good
11,431 reviews

Food

7.1

Overall

8.0

Boarding

8.1

Comfort

7.8

Entertainment

7.0

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.

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 18h 57m. The distance between Seattle and Sydney is about 7744 mi. This flight may include one or multiple stops.

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

    Cheapflights users have booked flights from Seattle to Sydney round-trip from $583. Other airlines that can offer you cheap pricing are Alaska Airlines, from $591, and Philippine Airlines, from $758. These flights start at 45% lower than the current average price 3 months from now.

  • What are the cheapest airlines to fly from Seattle to Sydney one-way?

    To fly one-way, consider booking your trip with ANA, which is currently one of the cheapest options available, starting at $253. Air Canada flights start at $366 while deals on Qantas Airways start at $380 one-way.

  • 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 L.A. Live are currently the most popular points of interest in Los Angeles at the moment. Hollywood Bowl, Hollywood Walk of Fame and L.A. Live are located about 12.5 mi, 11.7 mi, and 10.8 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 $38 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 $37 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, July is the cheapest month in which you can book a flight from Seattle to Sydney (average of $501). Flying from Seattle to Sydney in December is currently the most expensive (average of $845). 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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
Spokane to Sydney flights
Seattle to Coolangatta flights
Seattle to Newcastle flights
Portland to Coolangatta flights
Pasco to Sydney flights

Top 9 airlines flying from Seattle to Sydney

Discover the top 9 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 December 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
ANACheapest$583Average$615FlexibilityNo cancel feeOn-time80%
Alaska AirlinesCheapest$591Average$1,176FlexibilityNo cancel feeOn-time75%
Philippine AirlinesCheapest$758Average$921FlexibilityNo cancel feeOn-time60%
Air CanadaCheapest$779Average$1,051FlexibilityNo cancel feeOn-time67%
Qantas AirwaysCheapest$789Average$888FlexibilityNo cancel feeOn-time74%
American AirlinesCheapest$804Average$976FlexibilityNo cancel feeOn-time71%
Hawaiian AirlinesCheapest$813Average$1,155FlexibilityNo cancel feeOn-time85%
United AirlinesCheapest$831Average$1,127FlexibilityNo cancel feeOn-time69%
DeltaCheapest$842Average$1,150FlexibilityNo cancel feeOn-timeN/A

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.
Site
©2025 Cheapflights