The paper provides an overview of the organizational work among Slovenians in Toronto, Ontario, done immediately after the Second World War by a member of the Congregation of the Mission (Vincentian Fathers), Dr Jakob Kolarič (1902–1984) from Ljutomer. He endeavoured for the founding of the first Slovenian ethnic parish in Canada and built the first pastoral centre together with the community. He founded the Slovenian holiday retreat and started publishing a monthly called The Word of God to promote contacts among Slovenians spread across Canada. Moreover, Kolarič also ensured the establishment of a Slovenian school, bank, and various cultural and educational associations. After returning to Europe, he lived in Austrian Carinthia and put every effort into collecting documents on Bishop Gregory Rožman (1883–1959), the head of the Diocese of Ljubljana.