Canadian Senate Divisions

Canadian Senate divisions refers to two aspects of the Canadian Senate. First, it refers to the division of Canada into four regional Senate divisions of 24 senators each, as set out in the Constitution of Canada (as defined in subsection 52(2) of the Constitution Act, 1982, consisting of the Canada Act 1982 (including the Constitution Act, 1982), all acts and orders referred to in the schedule (including the Constitution Act, 1867, formerly the British North America Act), and any amendments to these documents. The four regions are the Western Provinces, Ontario, Quebec and the Maritimes. These regions are intended to serve the Senate's purpose of providing regional representation in the Parliament of Canada, in contrast to the popular representation that the House of Commons is intended to provide. While not within any of the original four Senate divisions, Senate seats are also allocated to Newfoundland and Labrador and the three territories. The four divisions can be expanded when the need arises to have an extra two senators appointed to each regional division.

Second, it refers to divisions within a province represented by senators from the Canadian Senate, also known as "senatorial designation". Under the Constitution, only Quebec has official Senate divisions for each of the senatorial designations within the province. In all other provinces, Senators are appointed to represent the province as a whole and the Constitution makes no reference to official senatorial designations for those provinces. Senators from provinces outside Quebec may simply "designate" a district they wish to symbolically represent within their province, which can be named at the time of their appointment or at a later time. These senate divisions have no specific geographic boundaries though their names often give a reference to a general geographic area. However a senator will sometimes create boundaries for their senate division even though it has no legal status. While relatively rare, a senator outside of Quebec can change his or her division in the same manner as party affiliation, simply by notifying the Clerk of the Senate.

...
Wikipedia