In 1902, a mosaic floor was laid in the main entrance of the original Parliament Building. The floor featured "1867" with a large representation of the coat of arms of the United Kingdom, surrounded by the provincial shields. Following the 1916 fire, the architects ensured thematic continuity in the new building, keeping a similar heraldic program in the main hall through the use of an ambitious sculptural program. The gables of the arches are decorated with the coats of arms of Canada, the provinces, their capital cities, and the territories. A variety of symbols, figureheads, flowers and fruits, as well as more than thirty different animals and sea creatures, complete the hall's ornamentation.
As early as 1941, sculptor Cléophas Soucy had designed and prepared most of the models for the gables of Confederation Hall. Due to the Second World War, carving did not begin until 1950. Following Soucy's sudden death in June of the same year, carving was completed under his successor, William F. K. Oosterhoff, in 1953.
Confederation Hall originally had two Canadian coats of arms: one on the south wall, the other on the north wall. To make room for the coat of arms of the newly created territory of Nunavut, it was suggested that the Canadian coat of arms on the south wall be removed. The shield on the south wall was resurfaced and the Nunavut coat of arms - carved by Maurice Joanisse, federal government sculptor since 1993 - was installed over it, thus placing it near the arms of the Yukon and the Northwest Territories. An unveiling ceremony took place in the hall on April 13, 2000, accompanied by a performance of Inuit throat singing and the traditional drum dance.