Plaid Cymru

Seats won by year

• Council
• Westminster
• Devolved
• Other

All election types, 2016 onwards. Devolved covers Holyrood, the Senedd, Stormont and the London Assembly.

By-election form, last 12 months

In the last 12 months of by-elections: defended 12 (held 10, lost 2); gained 4.

• HOLDHengoedCaerphilly County Borough Council · 6 Aug 2026
• HOLDBro'r LlynnoeddIsle of Anglesey County Council · 30 Jul 2026
• HOLDTrebanosNeath Port Talbot County Borough Council · 9 Jul 2026
• HOLDBarucVale of Glamorgan Council · 9 Jul 2026
• GAINGlantwymynPowys County Council · 2 Jul 2026
• GAINLlangennechCarmarthenshire County Council · 25 Jun 2026 · from Reform
• LOSSLlanrhaeadr-yng-NghinmeirchDenbighshire County Council · 25 Jun 2026 · to Independent
• HOLDTreorchyRhondda Cynon Taf County Borough Council · 25 Jun 2026
• HOLDActon and MaesydreWrexham County Borough Council · 18 Jun 2026
• HOLDGrosvenorWrexham County Borough Council · 18 Jun 2026
• HOLDQueenswayWrexham County Borough Council · 18 Jun 2026
• GAINVanCaerphilly County Borough Council · 19 Feb 2026 · from Labour

Where they're standing next

• SaronCarmarthenshire County Council · 22 Oct 2026

Strongest constituencies, 2024 General Election

• Dwyfor MeirionnyddWon53.9%
• Ceredigion PreseliWon46.9%
• CaerfyrddinWon34%
• Ynys MonWon32.5%
• LlanelliDid not win23.3%

Share of all votes cast in the constituency.