Walter-Patrice O'Leary (3 July 1910 – 13 September 1989) was a Canadian journalist, political activist and trade unionist.
While in Europe, O'Leary was vice president of the Foyer international des étudiants catholiques (France) and a member of the Mission universitaire catholique française and the Jeunesse universitaire catholique. In 1931, he founded the Action politique internationale des universitaires catholiques (Belgique). After returning from Europe, he became a journalist for L'Ordre.
Circa 1947, O'Leary was secretary of the Goodwill Mission Canada–Mexico (Mission de bonne entente Canada-Mexique). He served as president of the Quebec Popular Movement for Human Rights (Mouvement populaire québécois des droits de l'Homme) from 1966 to 1967, when he founded Quebec International (Québec inter-national). From 1968 to 1970, O'Leary was involved in efforts to disseminate and promote "La marche du Québec" (The March of Quebec), a Québécois patriotic song (see Music of Quebec). Subsequently, he was president of The Plateau in Montreal from 1974 to 1975. O'Leary served as secretary of the Parti Québécois' committee on international politics from 1976 to 1976 and was a member of the Saint-Jean-Baptiste Society's committee on international relations.
In the Quebec general election fo 1966, O'Leary stood as a candidate for the Rassemblement pour l'Indépendance Nationale in the Notre-Dame-de-Grâce riding. He placed fourth in the contest with 949 votes, losing to Quebec Liberal Eric Kierans.
O'Leary published articles in various French-language magazines and newspapers, including L'Indépendance, L’Ordre, and L'Unité.
He married Gratia Parent on 23 January 1960, at the age of 49. He fathered two children: Christian and Pascal.