Friedrich Oskar Ruge (24 December 1894 – 3 July 1985) was an officer in the German Navy and recipient of the Knight's Cross of the Iron Cross of Nazi Germany. He served as the first commander (Inspector of the Navy) of the post-war German Navy. He was the author of four books, including Der Seekrieg, the story of the German Navy in World War II, published in the United States by the U. S. Naval Institute.