Donald James Johnston, (June 26, 1936 – February 4, 2022) was a Canadian politician and lawyer. He was Secretary-General of the Organisation for Economic Co-operation and Development (OECD) from 1996 to 2006. Before, he was a member of the Canadian Parliament from 1978 until 1988. He was also President of the Liberal Party of Canada from 1990 until 1994.