John S. Macdonald
# John S. Macdonald

John S. Macdonald may refer to:

* John Sandfield Macdonald, first Premier of Ontario
* Harry Macdonough (John Scantlebury Macdonald), Canadian singer and recording executive of the early 20th century
* John S. MacDonald, Canadian engineer and businessman
* John Smyth Macdonald (1867–1941), British physiologist
