Editing Plaid Cymru (section)

===House of Commons===
{| class="wikitable" style="text-align:right"
|-
! rowspan=2| Election
! rowspan="2" |Leader
! colspan="3" | Wales
!UK
! rowspan="2" | +/–
! rowspan=2| Government
|-
! Votes
! %
! Seats
!%
|-
! [[1929 United Kingdom general election|1929]]
| rowspan="3" |[[Saunders Lewis]]
| 609 
| 0.003
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.0
| style="background:lightgrey;" |
| {{n/a}}
|-
! [[1931 United Kingdom general election|1931]]
| 2,050 
| 0.2 
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.0
| {{steady}}
| {{n/a}}
|-
! [[1935 United Kingdom general election|1935]]
| 2,534 
| 0.3
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.0
| {{steady}}
| {{n/a}}
|-
! [[1945 United Kingdom general election|1945]]
|[[Abi Williams]]
| 16,017 
| 1.2
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.1
| {{steady}}
| {{n/a}}
|-
! [[1950 United Kingdom general election|1950]]
| rowspan="10" |[[Gwynfor Evans]]
| 17,580 
| 1.2
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.1
| {{steady}}
| {{n/a}}
|-
! [[1951 United Kingdom general election|1951]]
| 10,920 
| 0.7
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.0
| {{steady}}
| {{n/a}}
|-
! [[1955 United Kingdom general election|1955]]
| 45,119 
| 3.1
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.2
| {{steady}}
| {{n/a}}
|-
! [[1959 United Kingdom general election|1959]]
| 77,571 
| 5.2
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.3
| {{steady}}
| {{n/a}}
|-
! [[1964 United Kingdom general election|1964]]
| 69,507 
| 4.8
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.3
| {{steady}}
| {{n/a}}
|-
! [[1966 United Kingdom general election|1966]]
| 61,071 
| 4.3
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.2
| {{steady}}
| {{n/a}}
|-
! [[1970 United Kingdom general election|1970]]
| 175,016 
| 11.5
| {{Composition bar|0|36|hex={{party color|Plaid Cymru}}}}
|0.6
| {{steady}}
| {{n/a}}
|-
! [[February 1974 United Kingdom general election|Feb 1974]]
| 171,374 
| 10.8
| {{Composition bar|2|36|hex={{party color|Plaid Cymru}}}}
|0.5
| {{increase}} 2
| {{no2|Opposition}}
|-
! [[October 1974 United Kingdom general election|Oct 1974]]
| 166,321 
| 10.8
| {{Composition bar|3|36|hex={{party color|Plaid Cymru}}}}
|0.6
| {{increase}} 1
| {{no2|Opposition}}
|-
! [[1979 United Kingdom general election|1979]]
| 132,544 
| 8.1
| {{Composition bar|2|36|hex={{party color|Plaid Cymru}}}}
|0.4
| {{decrease}} 1
| {{no2|Opposition}}
|-
! [[1983 United Kingdom general election|1983]]
|[[Dafydd Wigley]]
| 125,309 
| 7.8
| {{Composition bar|2|38|hex={{party color|Plaid Cymru}}}}
|0.4
| {{steady}}
| {{no2|Opposition}}
|-
! [[1987 United Kingdom general election|1987]]
|[[Dafydd Elis-Thomas]]
| 123,599 
| 7.3
| {{Composition bar|3|38|hex={{party color|Plaid Cymru}}}}
|0.4
| {{increase}} 1
| {{no2|Opposition}}
|-
! [[1992 United Kingdom general election|1992]]*
| rowspan="2" |[[Dafydd Wigley]]
| 156,796 
| 9.0
| {{Composition bar|4|38|hex={{party color|Plaid Cymru}}}}
|0.5
| {{increase}} 1
| {{no2|Opposition}}
|-
! [[1997 United Kingdom general election|1997]]
| 161,030 
| 9.9
| {{Composition bar|4|40|hex={{party color|Plaid Cymru}}}}
|0.5
| {{steady}}
| {{no2|Opposition}}
|-
! [[2001 United Kingdom general election|2001]]
| rowspan="3" |[[Ieuan Wyn Jones]]
| 195,893 
| 14.3
| {{Composition bar|4|40|hex={{party color|Plaid Cymru}}}}
|0.7
| {{steady}}
| {{no2|Opposition}}
|-
! [[2005 United Kingdom general election|2005]]
| 174,838 
| 12.6
| {{Composition bar|3|40|hex={{party color|Plaid Cymru}}}}
|0.6
| {{decrease}} 1
| {{no2|Opposition}}
|-
! [[2010 United Kingdom general election|2010]]
| 165,394 
| 11.3
| {{Composition bar|3|40|hex={{party color|Plaid Cymru}}}}
|0.6
| {{steady}}
| {{no2|Opposition}}
|-
! [[2015 United Kingdom general election|2015]]
| rowspan="2" |[[Leanne Wood]]
| 181,694 
| 12.1
| {{Composition bar|3|40|hex={{party color|Plaid Cymru}}}}
|0.65
| {{steady}}
| {{no2|Opposition}}
|-
! [[2017 United Kingdom general election|2017]]
| 164,466 
| 10.4
| {{Composition bar|4|40|hex={{party color|Plaid Cymru}}}}
|0.5
| {{increase}} 1
| {{no2|Opposition}}
|-
! [[2019 United Kingdom general election|2019]]
|[[Adam Price]]
| 153,265 
| 9.9
| {{Composition bar|4|40|hex={{party color|Plaid Cymru}}}}
|0.48
| {{steady}}
| {{no2|Opposition}}
|-
! [[2024 United Kingdom general election|2024]]
|[[Rhun ap Iorwerth]]
| 194,811
| 14.8
| {{Composition bar|4|32|hex={{party color|Plaid Cymru}}}}
|0.68
| {{steady}}
| {{no2|Opposition}}
|}

''*Six seats (Blaenau Gwent, Ceredigion & Pembroke North, Islwyn, Monmouth, Newport West and Torfaen) contested on a joint Plaid Cymru/[[Wales Green Party|Green Party]] ticket''