 The following year, he was appointed Vicar General for the Diocese of Chatham.In 1913 O'Leary became Bishop for the Diocese of Charlottetown on Prince Edward Island but as St. Dunstan's Basilica in Charlottetown had recently burned down, O'Leary was consecrated at the Sacred Heart Church in Bathurst.One of his first acts was to have a new cathedral built on the site of the ruined Basilica.