Mary Josephine Player (née Crampton; c. 1857 – 5 January 1924) was a New Zealand servant, midwife, welfare worker, feminist and social reformer.
She was born in County Kilkenny, Ireland in about 1857 as Mary Josephine Crampton.
She founded the Women's Social and Political League in Wellington and was its president for many years.
Through political infighting within the organisation, Player resigned the presidency and was replaced by Louisa Seddon, whose objective it was to endorse the increasingly conservative policies of the Liberal Government, which was led by her husband Richard Seddon.
She died by drowning in the Nelson suburb of Atawhai on 5 January 1924 at one of her daughter's homes; the coroner ruled that the death was a suicide due to depression.