William Parkin (24 August 1801 – 31 May 1889) was an English-born businessman, politician and philanthropist. He emigrated to the British Province of South Australia with his wife in 1839 and represented the City of Adelaide in the House of Assembly from 1860 to 1862 before becoming a member of the Legislative Council from 1866 to 1867. Parkin was a benefactor of the South Australian Congregational Church and founded many religious philanthropic efforts.