The daughter of Ernest Thomas and Pauline Eva (née Taylor) Bell Patricia Mackinnon was born in Brisbane and educated at St Margaret's Church of England School (Brisbane).
She married Alistair Mackinnon on 17 December 1936 and they were to have two children.
In 1948 Patricia became a member of the committee of management for the Royal Children's Hospital (RCH) Melbourne. She served in several offices before being elected vice-president from 1957-1965 and president 1965-1979, succeeding Dame Elisabeth Murdoch. In 1968 she began chairman of the RCH Research Foundation a position she held until 1986, and from 1951-1965, served as president of the Auxiliaries. She was also a federal and state councillor of the Australian Hospitals Association for many years. A member of the Alexandra Club, Melbourne, Dame Patricia Mackinnon enjoys gardening and reading.

Dame Patricia's links with the RCH go back to her grandmother-in-law, Lady Emily Mackinnon, who served on the committee of management (1888-1922). Her mother-in-law, Mrs Hilda Mackinnon, was elected president of the committee of management from 1923-1933. The MacKinnon School of Nursing is named in their honour.

Sources used to compile this entry: Herd, Margaret (ed.), Who's who in Australia 2002, 38 edn, Crown Content, Melbourne, 2002, 2020 pp; RCH MacKinnon School of Nursing and Bronwyn Hewitt at the RCH Archives..