Moir was born in
Edinburgh. He was the younger son of Margaret Louisa Maitland and her husband,
Dr. John Innes Allan Moir. His family, including older brother John William Moir (1851–1940), who later married Helen Elizabeth Tod, lived at 52 Castle Street in
Edinburgh's New Town. Through his nephew Dr. Henry Maitland Moir and his wife, Rose
Ochterlony, he was great-uncle to Father
John Maitland Moir (1924–2013), the Orthodox Chaplain to the
University of Edinburgh. ==Career==