Kate Siobhan Nicholl (born 4 May 1988)[4] is a Northern Irish politician for the Alliance Party, serving as a Member of the Legislative Assembly (MLA) for Belfast South since 2022.

Nicholl ran as one of two Alliance Party candidates, alongside Andrew Muir, for the constituency of Hollywood and Clandeboye in the North Down and Ards Borough Council, as a part of the 2014 local elections.

[16] Nicholl was chosen as one of two Alliance candidates for Belfast South at the 2022 Northern Ireland Assembly election, alongside Paula Bradshaw.

[2][18][19] On 7 May 2022, Nicholl was the final candidate to be elected for Belfast South, edging out incumbent Green Party MLA Clare Bailey.

"[23] Nicholl ran in Belfast South and Mid Down at the 2024 general election, coming second to the SDLP's Claire Hanna, increasing Alliance's share by 4.9% to 8,839 votes (20.3%).

[27][28] She was named after Nicholl's grandmother Evelyn, who was involved in anti-apartheid activism as a member of the Black Sash in South Africa.