John Clare Doneth was born December 28, 1910 in Copemish, Michigan to Peter and Sarah Doneth. Doneth attended Michigan State College, earning a bachelor's degree in agriculture in June 1933. He received his master's degree in agriculture economics from Cornell University in 1939. His early career was spent teaching vocational agriculture and coaching at Woodland High School, from 1934 to 1936. On July 15, 1936 he joined the Department of Agricultural Economics at MSC. He was promoted to assistant professor in 1939, associate professor in 1948, and full professor in 1957. Doneth was also an Extension Specialist in Farm Management, and in that role won the Superior Service Award from the U. S. Department of Agriculture in 1964. He founded the Telefarm Program, an electronic recordkeeping system for farmers. In January, 1973 Doneth retired from MSU with the title Professor Emeritus.

Doneth married Virginia Hoy-Prendergast of Owosso, Michigan, on December 28, 1948. They had four sons and three daughters. In his personal life, he was active in community and church affairs, including holding many council and committee positions. After his retirement from MSU, Doneth was coordinator and director of Friendship Travelers. Along with his wife, Virginia, he led over 23 groups to 60 countries.

Doneth died on March 15, 1986 at the age of 75.