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Cheap flights from Seattle to Sydney

SEA — SYD
22 Nov — 29 Nov1
1 adult
1 adult, Economy, 0 bags

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 23 October 2025.

Popular in

December

Cheapest in

September

Average price

C$ 1,359
Highest demand for flights based on searches. 12% potential increase in price (C$ 292 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease (C$ 50 potential savings vs. average RT price).
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Average for round-trip flights in October 2025
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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 17 October 2025.

The best time to book flights from Seattle to Sydney is 2 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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 C$ 812). Flying from Seattle to Sydney in January is currently the most expensive (average of C$ 1,208). 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 23 October 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Sydney at noon. If you’re flexible enough to do this you can expect to save up to 24% on your trip compared to booking a flight in the morning.

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 23 October 2025.
Read through reviews of airlines operating flights from Seattle to Sydney, such as United Airlines and Air Canada. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,995 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Crew

8.1

Food

6.6

Overall

7.4

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.
United Airlines
7.4
Good
8,995 reviews
United Airlines
7.4
Good
8,995 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Crew

8.1

Food

6.6

Overall

7.4

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.
Air Canada
7.1
Good
10,350 reviews
United Airlines
7.4
Good
8,995 reviews
Check prices

Comfort

7.3

Entertainment

7.1

Boarding

7.7

Crew

8.1

Food

6.6

Overall

7.4

Reviews

1 / 20
4.0
Okay

Tim,Sep 2025

IAD - GSP

This was pretty bad. It’s chaos at the Dulles boarding gates for the small regional jets because they use one gate to board 3-4 flights at a time. So, it’s difficult knowing where and when to go. There is little space for any size of carrry-on, so most had to gate check their bags. However, the worst of it was that our single flight attendant fell asleep before we took off and the pilot couldn’t do so until she responded to his messages. My wife had to wake her up! So we were a little late leaving. Not to be thwarted, the flight attendant fell asleep right after take off and there was no sight of her during the flight. When the aircraft touched down, a tray of unsecured canned drinks came crashing onto the aisle up front. I can only assume someone didn’t do what they were supposed to. The pilot was great, but I’m sure he must not be happy with this crew member.

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.

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

    Our cheapest airline available from Seattle to Sydney is Air Canada. Our recent data shows that you can find tickets from as low as C$ 1,084 on this airline. An additional option worth looking into is United Airlines, starting at C$ 1,158. Air Canada is 27% cheaper than the average price of flights available within the next 90 days 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 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 C$ 812). Flying from Seattle to Sydney in January is currently the most expensive (average of C$ 1,208). 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
Bondi Beach
Parramatta
Penrith

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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 629,999 searches. Data last updated 23 October 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 1,084AverageC$ 1,246FlexibilityNo cancel feeOn-time67%
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United AirlinesCheapestC$ 1,158AverageC$ 1,229FlexibilityNo cancel feeOn-time69%
Search United Airlines flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers 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?

Cheapflights makes it easy to find Seattle to Sydney flights by helping our users search from 900+ travel sites for deals. We also provide you with filters for cabin, price, airline, airports, number of stops, and many more to narrow down that perfect flight.

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

Cheapflights simply makes it quick and affordable to book flights from Seattle to Sydney by bringing together all flight options from hundreds of airlines and agencies online — and put it in one place for you to choose from. Plus, Cheapflights is 100% free to use for all.

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

Users can book flights with no change fees policies with our dedicated filters. Book flights from Seattle to Sydney flexibly with Cheapflights today.

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

Yes, Cheapflights has a feature called Price Alert, which notifies users when flight prices change. Track prices for your flight to Sydney from Seattle today and book when prices fit your budget.

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