William Ramsay, the son of William and Mary (nee McDonald), was a teacher and later became a headmaster of Invergordon Public School before commencing medical studies in 1884. He graduated with a BSc in 1888 and MB CM in 1892 from the University of Edinburgh. In 1904 Smith graduated with a DSc from the University of Adelaide and a MD in 1913 from the University of Edinburgh for a thesis on meical jurisprudence.

Smith married Margaret MacKenzie in 1889 and later moved to Adelaide in 1896 where he took up a position as physician at the Royal Adelaide Hospital. In 1901 he served in the South African War as surgeon captain, Imperial Bushman's Corps and in 1903 was appointed major in the Australian Army Medical Corps. He commanded the 1st Australian General Hospital Australian Imperial Force in Egypt during 1915.

Smith belonged to the Royal Anthropological Society of Great Britain and Ireland and devoted thirty years to a sympathetic study of the customs and psychology of Aboriginal people.

The image of Smith is courtesy of the State Library of South Australia: B7479.