Geoffrey Bertram Robert "Bob" Feilden CBE FRSFREng FIMechE (20 February 1917 – 1 May 2004) was a mechanical engineer, and an important part of the Power Jets team that developed the first jet engine with Frank Whittle in the early 1940s. He was Chair of the Committee on Engineering Design from 1961 and authored the 1963 'Report of the Feilden Committee on Engineering Design'.
Feilden was born in Meadway Court, Hampstead Garden Suburb, London on 20 February 1917. He was the son of Major Robert Feilden MC and Olive Binyon. He spent his early years in British Columbia, western Canada, as his father had ill health from being gassed in the First World War. He returned to England when he was eight, after his father died swimming in a lake in the Okanagan area.
He attended Heath Mount School in Hampstead, then Bedford School as a major scholar. In 1935 he worked for a year at British Thomson-Houston at Rugby (later to be the first home of Power Jets). He went to King's College, Cambridge in 1936, where he read Mechanical Sciences and Economics. In the summer holiday of 1937 he worked for Brown Boveri Company in Baden in Switzerland.
From 1939 to 1940 he worked for Unilever at Port Sunlight, arriving in September 1939, the very start of World War Two.
In 1940 he joined Power Jets, then at Rugby. He managed the engine test programme.
In 1946, through an acquaintance with Geoffrey Bone, the son of Victor Bone, he went to work for Ruston & Hornsby in Lincoln. He recruited some of his former colleagues at Power Jets.
In 1954 he became the Engineering Director, having seen the TA gas turbine enter production in 1952. The first commercial turbine was sold to an oil field in Kuwait. He also designed the AT diesel engine, also for marine applications.