Ruth Lilian Spearing CNZM is a New Zealand haematologist, and researches blood cancer.

[1] She has worked as a consultant haematologist at Christchurch Hospital since 1989, and is the clinical director of haematology at Canterbury District Health Board.

[3][4] Spearing led the New Zealand involvement in international collaborative trials with the UK's Medical Research Council and the Australasian Leukaemia and Lymphoma Group.

[2] In 2024 Spearing led calls for Pharmac chief executive Sarah Fitt to step down after an Official Information Act request revealed internal communications showing disdain for patients and their advocates.

[6][7] In the 2023 King's Birthday and Coronation Honours Spearing was appointed a Companion of the New Zealand Order of Merit for services to haematology.