John Fisher, son of a farmer, received his schooling in Lancaster and continued his studies at the Hariss Institute, Preston, where he obtained the National Diploma in Agriculture (NDA) and Lancashire County Diploma in Agriculture. After also obtaining the Diploma in Dairying at the Hutton School of Dairying he went to the University of Edinburgh, where he became an outstanding student and was awarded the Bachelor of Science (BSc) degree in Agriculture in 1909.
That same year Fisher emigrated to Natal where, from 22 August 1909, he had been appointed as biologist and lecturer in biology at Cedara, a research station of the Department of Agriculture and a School of Agriculture which later developed into the well-known College of Agriculture. In April 1913 he was promoted to vice-principal of the school. During 1917 he served as acting principal of the Elsenburg School of Agriculture, near Stellenbosch, until the appointment of Mr T.G. Reinecke from the beginning of 1918. He returned to Cedara at the end of 1917, where he became principal at that time and where he remained until his retirement in 1947. Under his guidance research was conducted that demonstrated the huge potential of the sourveld for cattle breeding and milk production. He was also in high demand as a judge of livestock at agricultural shows.
In January 1944, at the request of Prof R.B. Denison*, principal of Natal University College (NUC), Fisher prepared a report on the possible establishment of a Faculty of Agriculture at NUC. He envisaged a three-pronged faculty, situated at Pietermaritzburg, Cedara, and Baynesfield (the latter an estate left in trust for agricultural research by Joseph Baynes). Though the three-pronged approach proved impracticable, the establishment of the faculty was approved in principle in 1946. It came into existence in 1949, when NUC became the independent University of Natal.
Fisher contributed a number of articles to agricultural journals, for example, "Two fungus diseases of coniferous trees" (Agricultural Journal of the Union of South Africa, 1912); "Grasses for pastures in Natal" (Farming in South Africa, 1936); and "Farming in Natal, past and future" (South African Journal of Science, 1938). Shortly after his retirement he produced his most important publication, Farming, practical and scientific (Cape Town, 1949). Two years later he wrote Agricultural science for secondary and high schools (1951).
In 1936 the University of South Africa, through the Natal University College, awarded Fisher an honorary Doctor of Philosophy degree for his contributions to agriculture, particularly his research on cultivated pastures. He was a member of the South African Association for the Advancement of Science and in 1938 served as president of Section C (which included Agriculture).
After his retirement in 1947 Fisher took up farming near Nottingham Road and acted as technical adviser to Fisons Fertilisers. In 1916 he married Margaret Hamilton Ireland, with whom he had a son and a daughter.