He was born in Harlesden and educated at the Lower School of John Lyon (now The John Lyon School) in Harrow and at University College London. He joined the adult education staff of the University of Bristol in 1947, moving to the BBC in Bristol in 1954 as a radio talks producer and industrial correspondent. In 1966 he joined the staff of Bristol College of Science and Technology (which later became part of the University of Bath).
He was one of the most prominent personalities on the European museum scene and one of the pioneers of industrial archaeology in the 1960s, a broadcaster and the author of numerous books. In 1963 he wrote one of the first books on the subject, Industrial Archaeology: An Introduction, and in 1965 his Industrial Archaeology of Southern England. He was the first editor of the Journal of Industrial Archaeology in which, with others, he produced an annual review of the rapidly growing literature. In 1972 he published his book on Building Materials in the Longmans IA series, and in 1979 he co-wrote, with Julian Pettifer, Diamonds in the Sky, the result of historical research on the social history of air travel for the BBC television series of the same name.
The latter part of his career was largely devoted to work on museums, producing gazetteers such as the classic Cambridge Guide to Museums of Britain and Ireland (1987) on which he collaborated with Ann Nicholls.
He founded National Heritage, the UK museums action movement,in 1974 with John Letts and then the Museum of the Year Award. Subsequently he created the European Museum of the Year Award and the European Museum Forum, both aimed at stimulating the international interchange of ideas and creating networks of inspiration.
The Hudson Gallery at the Museum of Bath at Work was opened on 4 July 2007. Part of the exhibition is the result of contact with ten historical societies which each submitted four images and 100 words of text they felt best described their area. Other exhibits include the cabinet-making industry in the city and local inventors. Kenneth Hudson was one of the original trustees of the museum.