SEA to SYD, Seattle–Tacoma International Airport to Sydney Airport Cheap Flights

Based on HopeGoo data, All Nippon Airways offers one-way fares as low as US$297 on Cheapest nonstop routes (e.g. SEA to SYD on Mon, Mar 2), while Philippine Airlines offers Cheapest nonstop round-trips from US$1,048 departing on Thu, Apr 2 and returning on Thu, Apr 9.

At the moment, several airlines serve connecting flights from Seattle to Sydney, including: All Nippon Airways Selected airlines are based on historical data collected from flight bookings made by users on HopeGoo within the last 90 days.

By analyzing data from all airlines on the HopeGoo flight calendar, it looks like the best time to book a flight from Seattle to Sydney is around 40 days (6 weeks) in advance, and the best time to fly is usually on Tuesday, Wednesday, and Saturday. Tuesday typically offers the cheapest flights for departure, while Saturday offers the best return deals.

To find best deals on flights from Seattle to Sydney, you can use various tools on HopeGoo: · Be flexible with your travel dates to get the cheapest flight deal. Now the cheapest flight deal is on Mon, Mar 2, with one-way flights priced at just US$297. · Compare airlines strategically. Budget carriers often provide the lowest base fares, while we found the most affordable airline currently operating on this route is All Nippon Airways. · Set up price alerts to easily monitor ticket prices without having to check every day. · Check HopeGoo flight deals and promo codes frequently. · Avoid peak season unless you book very early. It seems the peak season for Sydney travel is around January. · Get exclusive promo codes for HopeGoo app users.

The cheapest months to fly from Seattle to Sydney is December, when demand for travel is lower.

After crunching the numbers on our February flight calendar, it's currently cheapest to fly from Seattle to Sydney on February 26, 2026 with Frontier Airlines, with prices starting at US$454.

You can land at any one of the following hubs in Sydney, with Seattle–Tacoma International Airport to Sydney Airport (SEA-SYD) is by far the most common option on this route: Sydney Airport (SYD).

The time difference between Sydney and Seattle is 18h.

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