Dame Kathleen Mary Ollerenshaw, DBE (née Timpson; 1 October 1912 – 10 August 2014) was a British mathematician and politician who was Lord Mayor of Manchester from 1975 to 1976 and an advisor on educational matters to Margaret Thatcher's government in the 1980s.

She was born Kathleen Mary Timpson in Withington, Manchester, where she attended Lady Barn House School (1918–26).

She wrote five original research papers which were sufficient for her to earn her DPhil degree without the need of a formal written thesis.

In 1942 she suffered a miscarriage and "cried nonstop for three days" as a result of stress when her husband was posted abroad for front-line war service.

Outside of academia, Ollerenshaw served as a Conservative Councillor for Rusholme for twenty-five years (1954–79), a member of the city council's finance committee (1968–71), a chairman of the education committee of the Association of Municipal Corporations (1967–71), Lord Mayor of Manchester (1975–76), High Sheriff of Greater Manchester from 1978 to 1979, and the prime motivator in the creation of the Royal Northern College of Music.

[10] Upon her death, she left a legacy in trust to support distinguished research visitors and public engagement activities at the School of Mathematics, University of Manchester.