Donald Macmillan (born 1902) was a son of to Murdo Macmillan and Christina Nicolson,14 Gravir.  

On March 18, 1924 he enrolled in the Royal Naval Reserve, Service Number  A11650 and re-enrolled under B7333, C6585 and D6142. His records indicate that he was 5ft 9¼ in tall with red hair, blue eyes and a pale complexion. He was living at 21 Lemreway, his maternal grandparent's croft. He worked as a fisherman on Bannf, Buckie, Fraserburgh, Inverness and Stornoway registered fishing boats, including the Violet and the Rose.

Donald was Mobilised on December 24, 1938 and served in the Royal Navy throughout the  Second World War. On Boom Defence based at HMS Fortitude, HMS Helicon,  HMS Orlando, HMS Spartiate II and HMS Victory I and aboard HMS Barsound. His name is mentioned in Roll of Honour: Pairc, Second World War.

He was a bachelor.