South Colby is an unincorporated community in Kitsap County, Washington, United States.

It is located on Yukon Harbor, 2 miles (3 km) west of the Southworth Ferry Dock.

South Colby is part of the Southworth census-designated place.

Colby is a shortening and alteration of "Coal Bay".

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