Fonds comprises Ronald St. John Macdonald's records regarding his personal, academic, and professional activities as a jurist, judge, and professor. Records include those related to Macdonald's involvement with Osgoode Hall, University of Western Ontario, University of Toronto, Dalhousie University, the European Court of Human Rights, the Hague, Peking University, World Academy of Arts and Science, Canadian Council of International Law, United Nations, Institute of International Law, African Society of International Law, British Institute of International Law, Canadian Institute of International Law, International Law Association, and others. Records types include correspondence; meeting minutes and agendas; research materials; photographs; newsletters; newspaper clippings; manuscripts; and off-prints.

Series comprises Ronald St. John Macdonald's records regarding his professional activities, including his involvement with different organizations, such as the Council of Europe, the European Court of Human Rights, the Hague, World Academy of Arts and Science, Canadian Council of International Law, United Nations, Institute of International Law, African Society of International Law, British Institute of International Law, Canadian Institute of International Law, International Law Association, and others. Series contains meeting agendas, meeting minutes, newsletters, reports, and other records.

Subseries consists of Ronald St. John Macdonald's records regarding his involvement with the United Nations. Subseries contains reports, meeting minutes, correspondence, press releases, and other materials.