The 2012 Cardiff Council election took place on Thursday 3 May 2012 to elect members of Cardiff Council in Wales. This was the same day as the national 2012 Welsh local elections. It was preceded by the 2008 election and followed by the 2017 election
Labour gained control of the council from the Liberal Democrats and Plaid Cymru, after gaining 32 seats. The Liberal Democrat leader of the council, Rodney Berman, lost his seat by 51 votes after two recounts, bringing Labour's gains to 33. Sixty-one-year-old Labour councillor Heather Joyce, nicknamed 'Supernan' by the local newspaper, became the new council leader.
Cardiff Greens
Cardiff Labour
Cardiff Liberal Democrats
Cardiff Plaid Cymru
<nowiki>*</nowiki> <small>= sitting councillor in this ward prior to election</small>
Fenella Bowden, elected as a Liberal Democrat in 2008, stood as a Heath & Birchgrove Independent.
Duncan Macdonald had been elected as a Conservative in 2008.
The by-election was caused by the resignation of Labour councillor Phil Hawkins for personal reasons.
A by-election was caused by the resignation of Labour councillor Luke Holland following accusations of non-attendance at council meetings. He stated that he planned to move to London.
The by-election was caused by the resignation of Labour Councillor Cerys Furlong on 30 December 2013.
The by-election was caused by the resignation of Labour councillor Siobhan Corria for personal reasons.
The by-election was caused by the resignation of Conservative Councillor Craig Williams, following his election as MP for Cardiff North.
The by-election was caused by the resignation of Labour councillor Cecilia Love for family reasons.
The by-election was caused by the death of Labour councillor Mohammed Javed.
The by-election was caused by the death of Labour councillor Chris Lomax.
Three seats were vacant by the end of the term caused by the resignation of Margaret Jones (Lib Dem) in Cyncoed, the resignation of Susan White (Labour) in Llandaff North and the death of Derrick Morgan (elected as Labour, then sitting as an Independent) in Llanrumny, all of happened within six months of the 2017 election, so no by-elections were held.