Llanrumney is an electoral ward in the east of Cardiff, capital city of Wales. It covers the working class residential community of Llanrumney. The ward has elected Labour Party councillors to the local Cardiff authority.

The Llanrumney ward is bordered to the south by the Rumney ward, to the north by Pontprennau and Old St Mellons, to the west by the River Rhymney and the Pentwyn ward.

It was created by The City of Cardiff (Electoral Arrangements) Order 1982 which came into effect from the May 1983 Cardiff City Council election.

Since 1983 the Llanrumney ward elected three councillors to Cardiff City Council and (since 1996) to the County Council of the City and County of Cardiff. Since 1983 the ward has consistently elected Labour Party councillors, with strong majorities.

Llanrumney councillors, John Reynolds and John Phillips, served as consecutive leaders of the Labour-controlled council in the late 1980s and early 1990s. Llanrumney councillor Heather Joyce became leader of the Cardiff Council between 2012 and 2014.

Llanrumney councillor, Keith Jones, was suspended from the Labour Party in 2022 and subsequently expelled from the party in May 2025, following an investigation into sexual harassment allegations. He continued to represent Llanrumney as an independent councillor.

^o existing councillor, though because of boundary changes not for the same ward

* = sitting councillor prior to the election