Editing House of Commons of Canada (section)

=== Composition ===
{{Main|Electoral district (Canada)|Member of Parliament (Canada)}}
The House of Commons is composed of [[Member of Parliament (Canada)|Members of Parliament]] (MPs), each of whom represents a single geographic constituency called an [[Electoral district (Canada)|electoral district]] (also known colloquially as a ''riding''). The constitution specifies that each [[Provinces and territories of Canada|province]] is entitled to one MP for every unit of population (called the ''"electoral quotient"'') it has, or part thereof, but additional MPs are allocated according to various clauses described below. Territorial representation is independent of the population; each territory is entitled to one seat. 

The number of MPs is adjusted periodically through a process called [[redistribution (election)|redistribution]] conducted in alignment with each decennial [[Census in Canada|census]]. Since 2025, when the [[2022 Canadian federal electoral redistribution|most recent redistribution]] took effect, there have been 343 MPs, distributed by province and territory as follows:<ref>{{cite web|url=https://www.elections.ca/content.aspx?section=res&dir=cir/red/arc/2012red/allo&document=index&lang=e|title=House of Commons Seat Allocation by Province 2012 to 2022|author=Elections Canada|year=2012|access-date=November 12, 2022|archive-date=January 3, 2022|archive-url=https://web.archive.org/web/20220103142349/https://www.elections.ca/content.aspx?section=res&dir=cir/red/arc/2012red/allo&document=index&lang=e|url-status=live}}</ref>  
<!-- begin Province table -->
{| class="wikitable sortable"
|-
! style="width:15%;"| Province
! style="width:10%;"| Population<br /><small>(2021 census)</small>
! style="width:10%;"| Total MPs
! style="width:10%;"| Average population per MP
|-
|[[Ontario]]
|align="right"|14,223,942
| style="text-align:center;" |122
| align="right" |116,589
|-
|[[Quebec]]
|align="right"|8,501,833
| style="text-align:center;" |78
| align="right" |108,998
|-
|[[British Columbia]]
|align="right"|5,000,879
| style="text-align:center;" |43
| align="right" |116,299
|-
|[[Alberta]]
|align="right"|4,262,635
| style="text-align:center;" |37
| align="right" |115,206
|-
|[[Manitoba]]
|align="right"|1,342,153
| style="text-align:center;"|14
|align="right"|95,868
|-
|[[Saskatchewan]]
|align="right"|1,132,505
| style="text-align:center;"|14
|align="right"|80,893
|-
|[[Nova Scotia]]
|align="right"|969,383
| style="text-align:center;"|11
|align="right"|88,126
|-
|[[New Brunswick]]
|align="right"|775,610
| style="text-align:center;"|10
|align="right"|77,561
|-
|[[Newfoundland and Labrador]]
|align="right"|510,550
| style="text-align:center;"|7
|align="right"|72,936
|-
|[[Prince Edward Island]]
|align="right"|154,331
| style="text-align:center;"|4
|align="right"|38,583
|- style="background:#faecc8" class="unsortable"
|'''Total for provinces'''
|align="right"|36,873,821
| style="text-align:center;" |340
| align="right" |108,452
|- class="unsortable"
|[[Northwest Territories]]
|align="right"|41,070
| style="text-align:center;"|1
|align="right"|41,070
|- class="unsortable"
|[[Yukon]]
|align="right"|40,232
| style="text-align:center;"|1
|align="right"|40,232
|- class="unsortable"
|[[Nunavut]]
| align="right"|36,858
| style="text-align:center;"|1
| align="right"|36,858
|- style="background:#faecc8" class="unsortable"
|'''Total for territories'''
|align="right"|118,160
| style="text-align:center;"|3
| style="text-align:right;"|39,387
|- style="background:#CEF6F5" class="unsortable"
| style="width:17%;"|'''National total'''
|  style="width:10%; text-align:right;"|36,991,981
| style="width:10%; text-align:center;" |343
| style="width:10%; text-align:right;" |107,848
|}

Section 51 of the [[Constitution Act, 1867]] specifies how seats are to be distributed among the provinces in proportion to population, subject to the following exceptions:
* Firstly, the "senatorial clause" guarantees that each province will have at least as many MPs as [[Senate of Canada|senators]].<ref name=constitution>{{cite web |url=http://laws.justice.gc.ca/eng/Const//page-3.html |title=Constitution Acts, 1867 to 1982 |author=Department of Justice (Canada) |date=November 2, 2009 |access-date=November 9, 2009 |archive-date=December 13, 2017 |archive-url=https://web.archive.org/web/20171213055311/http://laws.justice.gc.ca/eng/Const/page-3.html |url-status=live }}</ref> This provision was [[British North America Acts#British North America Act 1915|added to the constitution in 1915]].
* Secondly, the "grandfather clause" guarantees each province has at least as many Members of Parliament now as it has had since the [[2015 Canadian federal election|2015 election]].<ref name=constitution/>  This clause was [[Representation Act, 1985|added in 1985]], when it originally set the floor for each province as the number of MPs it had in 1985 (in effect the number of seats since the [[1979 Canadian federal election|1979 election]]), but it was [[Preserving Provincial Representation in the House of Commons Act|amended in 2021]] to be the number of members in the [[43rd Canadian Parliament]].<ref name="tabled">{{cite news |title=Liberals table bill to protect number of Quebec seats in Parliament, a condition of deal with NDP |url=https://nationalpost.com/news/politics/liberals-table-bill-to-protect-number-of-quebec-seats-in-parliament-a-condition-of-deal-with-ndp |publisher=National Post |date=March 24, 2022 |access-date=November 12, 2022 |archive-date=June 11, 2022 |archive-url=https://web.archive.org/web/20220611222554/https://nationalpost.com/news/politics/liberals-table-bill-to-protect-number-of-quebec-seats-in-parliament-a-condition-of-deal-with-ndp |url-status=live }}</ref><ref name="legisinfo">{{cite news |title=An Act to amend the Constitution Act, 1867 (electoral representation) |url=https://www.parl.ca/legisinfo/en/bill/44-1/c-14 |publisher=[[Parliament of Canada]] |date=March 24, 2022 |access-date=November 12, 2022 |archive-date=March 24, 2022 |archive-url=https://web.archive.org/web/20220324220852/https://www.parl.ca/legisinfo/en/bill/44-1/c-14 |url-status=live }}</ref>
* Finally, the "representation rule" ensures that any province that has historically been over-represented in proportion to its population (seven of the ten provinces, as of 2022) remains so, even if application of the other provisions would result in it shifting into being under-represented. This clause was [[Fair Representation Act (Canada)|added in 2011]].

As a result of these clauses, smaller provinces that have experienced a relative decline in population have become over-represented in the House. Ontario, British Columbia, and Alberta are under-represented in proportion to their populations, while Quebec's representation is close to the national average (107,848 as at the 2025 election, based on the 2021 census). The other six provinces are over-represented. The "representation rule" was added in 2011 with the intent of adding a ''de facto'' backstop to ensure that the disproportionate representation afforded those six provinces, which are all majority English-speaking, did not result in an overall linguistic bias in the composition of the House of Commons by ensuring French-speaking Quebec obtained sufficient additional MPs of its own to always remain just under the national average.

In Canada, the calculation of provincial representation considers the entire permanent population rather than citizens or eligible electors, in effect giving children and adults who do not qualify to vote equal weight to registrable persons. The ''electoral quotient'' had been 111,166 for the redistribution of seats after the [[2011 Canadian census|2011 census]] and is adjusted following each decennial census pro rata, by population change, since the previous decennial census.<ref name=C20>{{cite web |title=41st Parliament, 1st Session, Bill C-20 |url=http://www.parl.gc.ca/legisinfo/BillDetails.aspx?billId=5194714&Mode=1&Language=E |work=Parliament of Canada |publisher=Government of Canada |access-date=December 19, 2011 |archive-date=January 6, 2012 |archive-url=https://web.archive.org/web/20120106012308/http://www.parl.gc.ca/LegisInfo/BillDetails.aspx?Language=E&Mode=1&billId=5194714 |url-status=live }}</ref> The population of the province is then divided by the electoral quotient giving the base provincial-seat allocation.<ref name=constitution/><ref>{{cite book |first1=Robert J. |last1=Jackson |first2=Doreen |last2=Jackson |title=Politics in Canada: Culture, Institutions, Behaviour and Public Policy |year=2008 |publisher=Prentice Hall |location=Toronto |page=438 |isbn=9780132069380}}</ref> The "special clauses" are then applied to increase the number of seats for certain provinces, bringing the total number of seats (with the three seats for the territories), now, to 343.<ref name=constitution/> 

Following the apportionment of seats between the provinces, boundary commissions, appointed by the federal government for each province, have the task of drawing the boundaries of the electoral districts in each province.