William Harwar Parker (October 8, 1826 – December 30, 1896) was an officer in the United States Navy and later in the Confederate States Navy. His auto-biography, entitled Recollections of a Naval Officer 1841-1865, provides a unique insight into the United States Navy of the mid-19th century during an era when the Age of Sail was coming to an end and the advent of steam power and ironclads was beginning.