Roman Catholic churches in North America tend not to have gargoyles, in my experience. An exception to that is St. Peter’s Cathedral Basilica in London, Ont.
Its architect was the Irish-born Joseph Connolly who moved to Toronto after training in Dublin. Although he also designed secular buildings, he is principally known for his Gothic Revival churches. In fact, he was designed or remodelled upwards of 25 Roman Catholic churches and chapels in that style in Ontario alone.
London’s Bishop John Walsh, another Irish expat, chose Connolly as the cathedral’s architect. Work on the project began in 1880 and it was dedicated in 1885.
The cathedral has three arched doorways which are presided over by a slew of gargoyles (well, not strictly gargoyles seeing as they have no spouts).
Sometime later, two bishops were memorialized in stone on either side of the main door. On the right side of the door is Bishop Walsh, and on the left, Bishop John Cody, under whom the cathedral was completed (including two towers which were added in the 1950s) and became a Minor Basilica.