Ruth Harrison (1920—2000) was a leading British animal welfare activist and author.
In 1964 she published Animal Machines which describes intensive poultry and livestock farming. The book was said to have exposed the whole reality of intensive farming. It was published in seven countries and was the inspiration for the European Convention for the Protection of Animals Kept for Farming Purposes. In 1986 she was awarded an OBE.
Ruth Harrison is also the daughter of author Stephen Winsten.