Frederick Brundrett was born on 25 November 1894 in Ebbw Vale, Monmouthshire [Wales], the eldest son of Walter Brundrett, general secretary and accountant with the Ebbw Vale Steel, Iron, and Coal Company, and his wife, Ada. He was educated at Rossall School, Fleetwood, Lancashire, and at Sidney Sussex College, Cambridge, studying mathematics. In 1920 Brundrett married Enid James: their only child, a son, was killed in Italy in 1944.

Brundrett joined the wireless branch of the Royal Naval Volunteer Reserve in 1916, carrying out research work on underwater communications with submarines. In 1919 he joined the Admiralty and was sent to the Royal Naval Signal School in Portsmouth, where he played a leading part in the development of short-wave radio. Brundrett remained at the signal school until 1937, when he was transferred to the headquarters of the Royal Naval Scientific Service in London and promoted to principal scientific officer. He became a superintending scientist in 1939, assistant director of scientific research in 1940, deputy director in 1942, and in 1946 became chief of the Royal Naval Scientific Service. In 1950 he was appointed deputy scientific adviser to the Minister of Defence, serving first under Sir Henry Tizard and then under Sir John Cockcroft, whom he succeeded in 1954 as scientific adviser and chairman of the defence research policy committee, also taking on the position of Honorary Scientific Adviser to the Ministry of Civil Aviation (1953-59).

Brundrett's honours included the CB in 1946, KBE in 1950, and KCB in 1956. After his retirement in December 1959, Brundrett undertook many other tasks in the public service. He had already become chairman of the Civil Aviation Radio Advisory Committee (1958-60) and now also served as a civil service commissioner for seven years (1960-67), chairman of the Air Traffic Control Board, chairman of the naval aircraft research committee of the Aeronautical Research Council (1960-66) and was made Honorary Vice-President of the Society for Underwater Technology in 1972. Brundrett was also keenly interested in agriculture. He chaired the council of the Red and White Friesian Cattle Society, became president of the Agricultural Co-operative Association and helped to develop co-operative marketing for poultry and eggs. He was also chairman of trustees for the Rural Industries Bureau (1961-66), a member of the White Fish Authority (1961-73) and chairman of the Board of Governors for Houghton Poultry Research Station (1962-68). He died on 1 August 1974.