Sydney Falls, more commonly called Kotsuck Creek Falls or Kotsuck Falls, is a waterfall in the Mount Rainier National Park in the U.S. state of Washington.

The falls is formed as Kotsuck Creek, a tributary of the Cowlitz River, thunders 200 feet (61 m) into a steep and rugged canyon in a plume 75 feet (23 m) wide.

The falls start with a small tier of 30 feet (9.1 m), then splits into three streams and plunges over a sheer cliff face, joining together at the bottom.

The name "Kotsuck" comes from a Chinook Indian word meaning "middle".

This Pierce County, Washington state location article is a stub.