Rear Admiral Kenneth Haydn Farnhill CB OBE (13 April 1913 – 6 December 1983) was a senior Royal Navy officer.

Born on 13 April 1913, Kenneth Farnhill was educated at Bedford School.

He joined the Royal Navy in 1930 and served during the Second World War.

Promoted to the rank of Rear Admiral in 1966, he was Director of the Management of Intelligence at the Ministry of Defence between 1966 and 1969.

He retired from the Royal Navy in 1969 and was Secretary of the Defence, Press and Broadcasting Advisory Committee, responsible for issuing D-Notices, between 1973 and 1980.