Hotel St-Denis, then known as Hotel Pensylvania, opened on July 3rd, 1929. The opening was celebrated with a grand evening buffet during which the mayor at the time, M. Houde, sang " À la claire fontaine" . The owner, then M. Irwin N. Rollman, gave his guests an automatic golf shot calculator. The hotel was well-received in the lively francophone neighbourhood for its modern installations and numerous (100!) rooms.
The vaulted basement of he hotel was once a famed bar by the name La cave des moines. It hosted several wild nights as well as union meetings in the 1970s.