Canadian Senate divisions refers to two aspects of the Senate of Canada. First, it refers to the division of Canada into four regional Senate divisions of 24 senators each, as set out in section 22 of the Constitution Act, 1867. 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. 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.
Senate seats
thumb|300px|right|Map of the regional Senate divisions
Unlike the House of Commons, seats in the Senate are not based upon any population measure or adjusted by population (an exception to this was set out under the Manitoba Act, in which Manitoba's allotment increased until the province reached a target population). Rather, they are fixed under the Constitution Act 1867 (in the case of Quebec), or are established upon the appointment of a senator and cease to exist when the senator leaves office (outside of Quebec).